ChromaTalk Archives: November 2006

• Chroma to Chroma Interface Lead (2 messages)
• Re: Repairing (2)
• windows interface (9)
• European CC+ important update (4)
  • European CC+ update
• Fwd: two more fully-working chromas for sale! (2)
• Free to good home (SN 21030175) (22)
• Rhodes Chroma vs. Oberheim OB-Xa (21)
  • [Chroma on eBay]
• New feature requests for CC+ (27)
  • computer editing of the Chroma
  • Dave's knob box
• DIY solution for a potentiometer interface for the chroma (or other synths) (22)
  • Oups forgot the layout file
• Chroma Knob Slider Cap - Resource?
• Chroma on eBay (9)
• Polaris # 301936 (4)
• Chroma for sale (to the group first)
• Update on 21010250

Chroma to Chroma Interface Lead

Chris Ryan [21030691] · Wed, 1 Nov 2006 07:56:14 -0800

I've posted Chroma to Chroma Interface Lead, a wiring diagram and notes by Martin Straw [21010093+] for Chroma-to-Chroma connections (including the Polaris).

David Clarke [21030085++] · Wed, 01 Nov 2006 19:27:01 -0500

By way of cross reference, the pinout for the cable is also available in the Service Manual for the Chroma, on the Balanced Output Schematic and Interface Cable Schematic.

The operation/purpose of the Set-Split commands are summarized on the Parameter Chart, and are discussed more in the Programming Manual.

The Polaris User's Manual also contains some material on what settings are recommended in terms of what should be turned on/off (settings-wise) when connecting a Polaris <-> Chroma with this type of cable.

Re: Repairing

Go to first message in thread (October 2006)

David Clarke [21030085++] · Wed, 01 Nov 2006 19:32:42 -0500

The powersupply in my chroma makes buzz sound all the time.. like without earhconnection or somthing. It doesn't really bother...but anyone else had it also? ...

Julius - if the sound you're referring to isn't on the audio outputs, but is actually a physical sound being made by the Chroma, then what you're hearing is likely 'normal.'

The large transformer in the original Chroma power supply actually does 'buzz' when turned on. This isn't necessarily an indication of anything being wrong - just a result of the specific power supply implementation and design.

... I will give that info found there to rhodes technician that will check it here. He never saw (or heard) a chroma before.. If there is somebody that my technician could contact if needed, it would be very nice indeed.

The Service Manual for the Chroma is available on-line from the site - and the good news is that the Chroma is (generally speaking) a straightforward item to repair. If the technician has specific questions, this list itself would be a good place to start with the initial query.

Totte K [21010104] · Thu, 2 Nov 2006 16:31:05 +0200

Awww..sucks- when turning it on last time it made clear and sharp Bzzzzui! -sound and don't start at all anymore. The sound came about straight from under the power on/off button.

Guess have to get a new powersupply atleast now.(?) Well I was kind of prepared for this when I bought it so this is it... funny equipment.

Thank's for help David. Yes the buzz wasn't so bad before but this was more effective sound. I'll post what happens in the Future :)

windows interface

Michael Salmon [21030155] · Sun, 05 Nov 2006 06:23:45 +0000

hi list folks,

i was reading through the history and read the threads of mark david's development, but none of it is available. mark, if you're still here can you please open source your stuff or something? maybe if you're busy i'd be able to act as maintainer, like put it on sourceforge or something? i dont have a midi converter box, so im pretty interested in what you've done.

also, if anyone else has a midi converter design, so i can build it myself, that would be great. in the end i just want to save/edit native patches, as well as use it as a midi keyboard.

Mark's work was later posted in its entirety: see A Windows Interface for the Rhodes Chroma.

Chris Ryan [21030691] · Sat, 4 Nov 2006 23:00:21 -0800

I asked Mark several times if he would be willing to host his work on the site, but he never got it to me. I don't believe he's still subscribed to the list, unless he's changed his e-mail address.

Jesper Ödemark [21010135] · Sun, 5 Nov 2006 08:33:18 +0100

If you need editing options and midi I guess Sandro's and David Clarke's CC+ is the way to go... While on the topic, how's work proceeding on the european batch Sandro?

See European CC+ important update below.

Michael Salmon [21030155] · Sun, 05 Nov 2006 07:54:15 +0000

That is too bad... do you have his email addy in the archives? Maybe we can send another request? did anyone actually test the thing? also what was the url, maybe just maybe archive.org has a copy?

Chris Ryan [21030691] · Sun, 5 Nov 2006 10:15:57 -0800

I checked archive.org a couple of years ago, but it wasn't there.

I have e-mailed Mark again at the most recent address I have for him.

Chris Ryan [21030691] · Wed, 8 Nov 2006 23:41:22 -0800

Mark responded that he is willing to open the source. He has been extremely busy with work and will be even more so until the end of the year, and if he gets a weekend free he will get everything back together and send it to me so I can host it on the site. He asked me to remind him if he's not done so by January.

Michael Salmon [21030155] · Thu, 09 Nov 2006 08:00:02 +0000

That's good news, we all know what it's like to get shifting priorities...! You tell him to feel free and contact me directly to do a transfer. What do you think putting the code on sourceforge under whatever open source license he prefers (gpl, bsd, etc) - using a hosted sw revision control system is nice. the project homepage on the chroma website would be great too.

Dave Bradley [16330135] · Thu, 9 Nov 2006 08:41:19 -0600

How far did this project ever get? I thought that it was never finished, e.g. not in working order.

Michael Salmon [21030155] · Fri, 10 Nov 2006 20:53:06 +0000

from the history it doesn't seem like it got to working order, but if there's something to build off of it should help. even if the code doesn't map to my preferred environment, that's okay.

Go to next message in thread, March 2007

European CC+ important update

Sandro Sfregola [21010294] · Sun, 5 Nov 2006 17:58:13 +0100

I'm really sorry to inform all the European CC+ customers that unfortunately there will be a delay in the shipment: a couple of parcels containing electronic components got trapped somewhere in the Italian mail distribution and I'm doing all the necessary work to solve this problem.

I will let you know of any progress: please be patient.

Jesper Ödemark [21010135] · Sun, 5 Nov 2006 19:49:23 +0100

Thanks for the update... I hope they're not like their spanish colleagues. I sold two Ddrum pads to a guy in Spain, they're made the round trip twice due to bad postal services.

Olli [21010284] · Mon, 6 Nov 2006 09:52:09 +0100

oh well, this is common practise in france, too. i have had countless issues like that with those guys... very, very, very annoying

Sandro Sfregola [21010294] · Wed, 22 Nov 2006 01:02:12 +0100

European CC+ update

A quick update about the "batch #2" European CC+: one of the 2 parcels I was waiting for has arrived; the other should be here soon.

Again, I'm really sorry for the delay; I hope you will understand: I'm doing all the possible.

Fwd: two more fully-working chromas for sale!

Chris Ryan [21030691] · Sun, 5 Nov 2006 12:24:07 -0800

From Peter Forrest (The A-Z of Analogue Synthesizers [1]):

The VEMIA auction ending Nov 11 has two more fully-serviced Chromas for sale. lots 5213 and 5214.

One is s/n 21010118, and one is 21030858.

I don't know a lot about them apart from the fact that I transported them to Roy Paynter's from the owner's a few months ago. They were both owned by a big collector in the north of England who has decided to sell up practically his entire collection. If anyone on chromachat is interested but can't get on to / with the website, they could email me directly to discuss these (or the other of the three in the auction). If they don't sell, there is a second chance Snday immediately after the auction, in which some items will have reduced prices.

Peter Forrest [21010096] · Sun, 5 Nov 2006 20:36:01 -0000

Thanks, Chris!

There's now a Polaris as well. lot 5227.

Peter

PS Snday is of course short for Sunday...

Free to good home (SN 21030175)

Brian Robison [21030175] · Sun, 5 Nov 2006 17:08:35 -0500

This past summer, I inherited Chroma SN 21030175. It is NOT currently working. David Clarke [21030085++] provided many helpful hints to me in early July, but for the past four months I've been too busy to pursue his suggestions, and it could be many more months before I get back to the repair effort... and frankly, I'm much more interested in other projects that more closely fit my professional interests (e.g., re-fretting a guitar in 31-tone equal temperament).

Because I paid nothing for this instrument, I feel it would be unethical to sell it, especially given its current condition (viz., defunct). Given the cost of shipping such a behemoth, I'd prefer to have someone come to Cambridge and pick it up in person. As of this writing, I expect this semester to be my last at MIT, so pickup would need to take place sometime in late December or early January.

So, if there's anyone out there who would be interested in reviving it, please contact me directly at one of the addresses below. [Removed.]

Dave Bradley [16330135] · Mon, 6 Nov 2006 14:58:40 -0600

I'd certainly pay for shipping if you can't give it away locally. Please contact me if interested.

Jesper Ödemark [21010135] · Tue, 7 Nov 2006 07:40:12 +0100

One of few times I regret not living in the States! ;)

Peter Forrest [21010096] · Tue, 7 Nov 2006 07:48:36 -0000

Don't forget that if you lived in, say, LA you would have as much trouble picking it up from New England as a Lapplander picking something up from the tip of mainland Greece...

Olli [21010284] · Tue, 07 Nov 2006 09:00:03 +0100

hehe i guess he was aware that he was overly simplyfying it, lol

Lars Johansson [21030632] · Tue, 7 Nov 2006 09:09:31 +0100

Hey hey hey......wait a minute, Jesper isn't a Lapplander anymore than you Peter is Scottish.

Lappland is 1500 kilometers away from where Jesper lives.

However, I live roughly 150 kilometers from Lappland. It still doesn't make me Lapplandish.

Peter Forrest [21010096] · Tue, 7 Nov 2006 08:26:47 -0000

hehe I wasn't meaning that Jesper was a Lapplander. Just that it's a hell of a lot further from the south-west of the US to the north-east than it is from the northern tip of Europe to the south (I think!!).

Olli [21010284] · Tue, 7 Nov 2006 09:31:33 +0100

enlighten me, whats the problem with being lapplandish?

Jesper Ödemark [21010135] · Tue, 7 Nov 2006 09:45:09 +0100

Sure, but;

• There's 25% VAT on import costs here
• I'm not in Lappland but at the other end of Sweden, some 1800 kilometers away.
• I'm no tech wiz
• I have no space for another Chroma ;)

...and if I would live in the US, California wouldn't be my choice. I spent a month there in 1990 and it was far too HOT!

electronically yours, jesper - without polar bears on the streets though ;)

Jesper Ödemark [21010135] · Tue, 7 Nov 2006 09:50:41 +0100

Prejudices (is that the word?);

• They hardly ever speak
• All wears knife (like the finnish people ;) )
• They're either unemployed or herding reindeers
• They all drink home-brewn booze
• They have at leasy 50 kilometers to the closest neighbour

etc.

Jesper Ödemark [21010135] · Tue, 7 Nov 2006 09:47:53 +0100

Don't forget that Geenland is part of Denmark and that Svalbarden/Spitsbergen as well as parts of Antarctica is norwegian territory!

electronically yours, jesper - getting off-topic like hell here

Peter Forrest [21010096] · Tue, 7 Nov 2006 08:47:42 -0000

Lack of sunlight in the winter? :o)

No, it's an amazing place with a resourceful, resilient population. It's a long way from, say, Athens Greece, but I think(without actually checking) I'd rather collect a Chroma from there if I lived in Athens than..... OK, one from Portland OR if I lived in Orlando FL....

(notice the use of the word Chroma :o))

Jeffrey D. McEachin [21030073+] · Tue, 07 Nov 2006 01:00:44 -0800

Cool! They sound like my kind of people! I think I'll take my next vacation in Lappland!

Lars Johansson [21030632] · Tue, 7 Nov 2006 10:02:45 +0100

http://www.saami.info/jojk/renar_thomasegemyrponga.wav

Imagine this with a fat Chroma-backing !

LJ - Like to work with Sami-musicians

http://medlem.spray.se/waveterm/LJLab2006/ [link obsolete in 2009]

Peter Forrest [21010096] · Tue, 7 Nov 2006 09:16:14 -0000

All I know is that going as a tourist in full-moon mid-winter and driving huskies thru a silent woodland is about the best thing I ever did in my life ;o)

(not to mention diving into the snow at -30 deg from a sauna at +50)

Peter

(and trying to sleep in an igloo was the worst).

PS Anyone heard of the mythical 2105 weather-hardened reindeer-fur-lined Chroma aimed at the Arctic market? :o)

Jeffrey D. McEachin [21030073+] · Tue, 07 Nov 2006 02:09:31 -0800

I'd rather collect a Chroma from there if I lived in Athens than..... OK, one from Portland OR if I lived in Orlando FL....

So, what's wrong w/ Portland OR?

We hardly ever speak (unless we feel like speaking to you) I wears knife (don't know about anyone else - I never ask to see anyone's knife!) We're either unemployed or herding cats (I know that's my job description) We all drink home-brewn booze (best beer in the US!) We have at least 50 feet to the closest neighbor

And we have a lack of sunlight in the winter. That's the best part!

It's all good. See you in Lappland for a Chroma jam!

;)

Olli [21010284] · Tue, 7 Nov 2006 11:16:15 +0100

PS Anyone heard of the mythical 2105 weather-hardened reindeer-fur-lined Chroma aimed at the Arctic market? :o)

the only thing i know that the looks of mine when i got it after 15 years sitting in the anvil case with tremendous foam rot was pretty close, hehe

Jesper Ödemark [21010135] · Tue, 7 Nov 2006 13:31:58 +0100

My thoughts goes toward the only 2102 which has only surfaced in Stockholm. I think _THAT_ is a re-furbished Lapponia-Chroma! ;)

Doug Wellington [21030300] · Tue, 7 Nov 2006 07:35:58 -0700

...and if I would live in the US, California wouldn't be my choice. I spent a month there in 1990 and it was far too HOT!

Nah, that's not hot. You should come here to Arizona! :-)

Doug (Moved here from California too...)

Chris Ryan [21030691] · Tue, 7 Nov 2006 21:11:41 -0800

Anyone heard of the mythical 2105 weather-hardened reindeer-fur-lined Chroma aimed at the Arctic market? :o)

One or two were spotted in Nunavut (for those who don't know, that's a territory in northern Canada) but due to the disappearing Arctic ice, upon which they depended, I believe they are now extinct.

Brian Robison [21030175] · Wed, 08 Nov 2006 13:04:10 -0500

Thanks to everyone who expressed an interest in Chroma 21030175.

Believe it or not, I was worried that I might have no takers. Instead, there are a dozen or so. I've been too busy to reply individually, so my apologies for this reply through the list.

Sometime later this week, I'll send a more detailed description of the instrument's current state to everyone who e-mailed me. (If you telephoned without sending an e-mail, please send me a note with your e-mail address.) People can then let me know whether they're still interested, and from the remaining pool, I'll create a lottery.

Mark A. Lange [21030459+] · Wed, 8 Nov 2006 12:13:35 -0600

Too much fun! How much are the tickets :)

Rhodes Chroma vs. Oberheim OB-Xa

Tom Hughes [21030251+] [21030251] · Tue, 07 Nov 2006 07:49:39 -0500

Hi,

I finally found someone to take a look at my recently acquired non-functioning Chroma, so I still don't have any first hand experience with it. But I have, in the meantime, gotten a hold of an Oberheim OB-Xa and I think it's great. I'm wondering who has had both the Chroma and OB-Xa and what observations people might have comparing and contrasting the two. I'm aware that the Oberheim is very limited in comparison in terms of control over the various parameters. So I guess I'm looking for sound comparisons, or anything else that might seem relevant or interesting.

Chris Ryan [21030691] · Tue, 7 Nov 2006 20:58:57 -0800

I bought an OB-8 (the OB-Xa's successor) in the summer of 1983. It had that nice Oberheim sound, but it was very unreliable (in my limited experience, far more so than the Chroma). After months of attempting to have it serviced, I returned it and bought my Chroma that December. I still remember that my impressions of the Chroma in comparison were that it was from, or heralded, a new class of synthesizers; more importantly, it seemed to me more like a musical instrument than the Oberheim. That was partly the keyboard, but also the sonic (programming) flexibility. In fact, I had looked at the Chroma just before my Oberheim finally arrived, and recall it being a little intimidating (as well as more expensive), both because of the single-slider interface and, I think, because it seemed somehow a more "serious" or "advanced" keyboard. My friends encouraged me to go with the Chroma (actually chanting, "Chroma ... Chroma ... Chroma"), but the OB-8 was already pre-ordered.

Jesper Ödemark [21010135] · Wed, 8 Nov 2006 07:44:36 +0100

What a beautiful story from the past - here's another! :)

I was 9 at the release of the Chroma and was still more interested in LEGO than musical machines but I remember seeing my first Chroma in 1990 or so. This was just before the boom of vintage analogue synthesizers and a guy in Malmö (the biggest town nearby and just across the bridge from Copenhagen) had realised what was about to happen so he bought literally tonnes of synthesizers in the US and shipped a container full of stuff to Sweden and his vintage music shop.

The broken stuff was slowly put back in service and the shelves were always full of cool but expensive stuff (remember, I was now 16). I used to visit the shop and go drooling over stuff like the MS-20, Axxe, SH-2 etc. And there also was a Chroma, next to a Rhodes piano and a PPG (I think).

I remember thinking it looked big, big, big and wondered what crazy person would build such an impressive instrument without the ability to program it properly. I was convinced that there were some knob box available that had been lost for this one...

Now I know better... and soon I'll be able to control my Chroma with a knob box if all goes according to plans!

Rob Belcher [16330123] · Wed, 08 Nov 2006 06:57:45 +0000

Hi Jesper, Who is making the knob box for the Chroma for you? I'd love to get one for mine...

Jesper Ödemark [21010135] · Wed, 8 Nov 2006 08:10:35 +0100

My knob project will take advantage of Sandro's and David's CC+ and then add a Doepfer Pocket Dial on the midi chain. I spoke to Sandro about this and he said it should work. I'll keep you posted when the CC+ has arrived, has been installed and the Pocket Dial has been programmed to send on the right channels... (expect a few more months ;) )

If it works as I hope I'll do a Chroma-style new case for the Pocket Dial. %)

Rob Belcher [16330123] · Wed, 08 Nov 2006 09:48:31 +0000

Oh right, nice :)

It would be cool, if an enclosure is made for a knob box, that maybe we could do a group thing and get a few done at the same time? Id love one for my Expander, or even a VST editor for it...

I have a CC+ kit coming from Sandro too, i had one reserved for me early in the ordering for the second batch of kits.

(Sandro if you reading this i will send money for kit very very soon ; )

Rob Vandivier [21030396] · Wed, 8 Nov 2006 10:54:04 -0500

I always wanted them knobs. Keep us posted!

Tom Hughes [21030251+] [21030251] · Sun, 12 Nov 2006 15:02:31 -0500

Anyone else with any Chroma vs. OB-Xa stories?

Mal Meehan [21010182++] · Sun, 12 Nov 2006 20:22:41 +0000

Not had an OB-XA but had an OB-8 set-up with my Chromas (but sold the OB-8 last year).

My OB-8 was very reliable (slightly different experience to the previous post) but i do know that their eproms can go and if that happens then you lose everything.

I liked the sound of the Oberheim and it could sound quite big if you doubled up the patches but for me it didn't have the organic sound of the Chroma.

Sure, it was possible to set up some killer modulation on the OB-8 and have 2 different vibratos coming in at different delayed times but everything sounded nice and predictable...

I think some of that may have been down to the non velocity keyboard but also the Oberheim is quite a clean sound.

I do however like the filters on the OB-8... and I hear the OB-X/Xa filters are even more powerful... some great lead screechers coming out of those synth.

Not sure you can compare the two units though as the Chroma is a league above the likes of the OB range... the Jupiter Range ... the Prophet range etc (I have owned them all)...

There are very few synths that you can compare a Chroma with, and I actually think the Chroma can emulate a lot of its peers... however, one thing lacking on the Chroma for me is the hands-on control that the other synths have... I really do think there is a need for that knob box guys!!!

Dave Bradley [16330135] · Sun, 12 Nov 2006 15:43:26 -0600

For me back in the day, the only synth to compare with my Chroma sound complexity wise was the Oberheim Xpander. Other than that, nothing compares until Andromeda came out.

Jack Colburne [21030142+] · Mon, 13 Nov 2006 00:02:42 -0500

Yeah, I always considered the Xpander / Matrix-12 as the only other analog synths in the same league as the Chroma. The OB series sounds wonderful, but they're pretty straight forward as far as voice architecture goes. The flexibility of the Xpander family was, like the Chroma, a programmer's dream.

Now that the Red Sox have won a World Series, if I can ever get my hands on a working Matrix-12 (basically 2 Xpanders w/ keyboard), I can die happily.... as long as I get to play with and MIDI up the Chromas and Matrix for a while first.

To me, the high-end mainstream competitors were the OB-Xa/OB-8, Roland Jupiter 8 (later the MKS-80 Super Jupiter), the Prophet series (5, 10, T8), the Yamaha CS-80 (sortof), and, for a while, the MemoryMoog (absolutely massive sounding beast). I think of them in "the same breath" The Chroma and Xpander/Matrix were clearly in a class of their own.

Mal Meehan [21010182++] · Mon, 13 Nov 2006 06:23:04 +0000

I had a Matrix12 sat above a Chroma in my set-up for some years... Impressive machine but somehow i never got on with it.

I bought one because of the legend that goes with it and like the CS-80, if you are collecting it's a must have synth but for me the sound was just too perfect.

It was a great synth to program with the displays and the soft knobs... a fore runner in design to all the midi controller keyboards available today but again, just like the OB range the M12 was a little too controlled for me... I like my analogs to sound organic and slightly out of control but the Matrix12 had too clean a sound... there were some string and brass patched on it that could give a Triton a run for its money!

The problem for me is that both the Chroma and something like the Matrix12 are what i call "locked out" synths... it's quite difficult to program on the fly compared to something like a jupiter 8 or Memorymoog etc.

Up until recently I owned 3 Chromas as the best working method for me is to load up my favorite patches and then use them effectively as preset synths... the new computer board will help with that by allowing more patches to be saved on a single unit but the Chroma is seriously lacking in immediacy compared with a CS80 or similar.

To me, the high-end mainstream competitors were the OB-Xa/OB-8, Roland Jupiter 8 (later the MKS-80 Super Jupiter), the Prophet series (5, 10, T8), the Yamaha CS-80 (sortof), and, for a while, the MemoryMoog (absolutely massive sounding beast) I think of them in "the same breath"

I actually think that the Chroma is above pretty much all the synths you listed... I would suggest the Chroma could be compared to the CS-80 because of the vast double sound engine and after touch keyboard, and possible the Matrix12 as discussed, but the Jupiter 8, Memorymoog and P5 are all lesser range synths. The SCi T8 has a build quality that would be up there with the Chroma and has a very nice keyboard action but the sound engine is actually quite weak (although the velocity and aftertouch make up for it).

I would put the Chroma up there with the likes of the PPG Wave2.3, Synclavier II, Crumar GDS/Synergy and even the DX range (DX1 naturally)... other then the CS-80 I don't think there's another analog synth you can match it to for quality of sound and it can only be matched to some of the more up market digital synths that came later for features (and very few synths for build quality).

Jesper Ödemark [21010135] · Mon, 13 Nov 2006 08:16:59 +0100

Not sure you can compare the two units though as the Chroma is a league above the likes of the OB range... the Jupiter Range ... the Prophet range etc (I have owned them all)...

So, which are _in_ the Chroma range then? Not the Polaris I guess. The T8? The CS-80? The PS-3300? (the 3200 sure wasn't, I've owned one) The Matrix-12? Funny how all these (if they qualify) cost at least twice that of a Chroma these days. I saw the Chromas at Vemia going cheap.

There are very few synths that you can compare a Chroma with, and I actually think the Chroma can emulate a lot of its peers... however, one thing lacking on the Chroma for me is the hands-on control that the other synths have... I really do think there is a need for that knob box guys!!!

Amen! I sure hope it'll work out 'cause my invested euros are meant to give it knob control. I have a newly switched PSU so that shouldn't 'cause any troubles... I also think that the lack of knobs is the reason for the second hand price!

Jesper Ödemark [21010135] · Mon, 13 Nov 2006 08:57:02 +0100

I'm still in the process of getting my badly battered VX-600 back into shape but I've heard only good things about it and its modulation possibilities so maybe that goes in there too... But not the feel of the keys though which is basic crap.

Mal Meehan [21010182++] · Mon, 13 Nov 2006 08:23:39 +0000

So, which are _in_ the Chroma range then? Not the Polaris I guess. The T8? The CS-80? The PS-3300? (the 3200 sure wasn't, I've owned one) The Matrix-12? Funny how all these (if they qualify) cost at least twice that of a Chroma these days. I saw the Chromas at Vemia going cheap.

The Polaris is like the "Juno" range for Roland... and the Korg PS range are great but they are not strictly analogue polysynths as they use divide down oscilators... I'm surprised you didn't like your 3200 as I have always found the PS3100 fun and quite lush sounding (for strings anyway). Forgetting sound then I would rate the Chroma along side the CS80, T8, DX/GX1, Synergy and Synclavier II for build quality (although both the Jupiter 8 and Memorymoog have great build quality... just not enough grandeur).

I think the cost of Chromas unlike other synths does not reflect the quality of the unit... mainly because there are many "non-functioning" Chromas out there going cheap. Also, unless you know about the Chroma you are unlikely to buy one if you see one... it has a slightly unfriendly face compared to a Jupiter or a Prophet which has an immediacy because of all the controls. I know a lot of well known synthesists who wouldn't go near a Chroma but soon as you get them in front of one and playing they love the sound.

There's a very small market for Chromas so prices are reasonably level ... I have never paid more than £800 for a Chroma and I have owned 4 over the last 16 years but prices are rising as it becomes easier to fix and better documented (Thanks Chris!), I could foresee a situation in the future when someone takes the leap and re-issues technology based on the Chroma architecture... add a knobby interface to a Chroma and you have a synth that can still outshine the current crop of new analogue polysynths (Andromeda, polyevolver etc).

Mal Meehan [21010182++] · Mon, 13 Nov 2006 08:26:11 +0000

VX600... Is that the little Akai thing?

How can you rate that along side the Chroma?

The AX-80 perhaps, as the gas displays are quite interesting and the sound was very phat but the VX600... surely not?

Jack Colburne [21030142+] · Tue, 14 Nov 2006 02:20:12 -0500

I actually think that the Chroma is above pretty much all the synths you listed...

I was agreeing with you, hence the Chroma is not on that list. I meant that they were competing with each other, and that, to me, the Chroma and Matrix were in a league of their own.

That's also why I bought my first Chroma when it was new. (Used most of them plenty, but, except for an MKS-80, did not own them as "new").

I understand what you mean by the Chroma sounding "organic". And flexibilty-wise, if I needed something programmed quickly, I would turn to one on the list. But when I wanted something never heard before (at least by me, and usually musical) or wanted to explore the possibilities, I'd use the Chroma.

Even though we should discuss and compare vintage synths, it's easy to forget that they each had very different and characteristic sounds (the enduring and classic ones, anyway) making it hard to place them in any "other-than-specs" heirarchy except personal-preference. They were not trying to be the same thing. It would get to the point where a producer would demand a Rev 2 Prophet-5 and frown upon a later Rev 3 (different oscillators). Many players used to be able to recognise a particular synth on a recording the way a guitarist can tell a Strat or Rickenbacker 12-string from a mile away. (The CS-80 is a primo example of that). And the different sounds of the different synths could serve different purposes.

We all agree on the musicality of the Chroma; I rarely used it on anything that was not music related. (For me, the Prophet was great for sound effects of all types). And for me, the CS-80 had the same kind of musicality; in the pop world, Toto's "Africa" was always a great example of a synth as "living" musical instrument... not the soaring leads or the Emulator kalimba, but the thick, textured pad throughout. Simple and gorgeous.

I am not nearly as familar with many newer synths, but, though still not analog, the Kurzweil K2000, then the K2500 are the closest I've come to the level of programibility/flexibility of the Chroma/Matrix, etc. Not to sound like a commercial, but the limit using the V.A.S.T. engine was pretty much your imagination. As a sampler and a subtractive synth, they are extremely powerful. It was very convenient to be able to sequence an orchestral piece, a rock tune, a classic rock piano/organ tune, and a pseudo-analog trance piece on the same synth... with nothing else. I even used some key-mapped open-filter oscillator samples from my Jupiter to vary the Kurzweil's "analog" sound. But they can still be fairly static compared to true analog. I still have and will always use my K2000 and K2500.

... it's quite difficult to program on the fly compared to something like a jupiter 8 or Memorymoog etc.

I totally agree. One of the reasons that it was never a synth for "everyone". You always had to think about what you were doing... you can't just grab some knobs/sliders and see what happens...there is something to be said for grabbing the envelope sliders with one hand and shaping it in a single move.

The SCi T8...sound engine is actually quite weak.

Always thought it sounded like a "lesser" Prophet (more like a Prophet-600?) But as a "major" synth, I put it in the list anyway. Nice touch-sensitive keyboard. ... I still liked it. :-)

I would put the Chroma up there with the likes of the PPG Wave2.3, Synclavier II, Crumer GDS/Synergy and even the DX range.

I never really think of the Chroma in comparison with any of the digtals you mentioned. Considered a Synergy once, but couldn't program it without a GDS.. a pretty expensive preset machine. Still have a TX-7 module (program it via MIDI), but I was never a very big DX fan. My favorite DX-type sounds are "chiffy" sorts of sounds (e.g. Jefferson Starship's "We Built this City").

...(and very few synths for build quality)

Hmmmmmm... I had more problems with my Chromas than any other machines I ever owned. (but it was worth it). It's easily more delicate than any other beast I've used. Had the least problems with Rolands, and, interestingly enough, I never had problems with the Kurzweils.

Mal Meehan [21010182++] · Tue, 14 Nov 2006 10:54:20 +0000

Many players used to be able to recognise a particular synth on a recording the way a guitarist can tell a Strat or Rickenbacker 12-string from a mile away. (The CS-80 is a primo example of that). And the different sounds of the different synths could serve different purposes.

Yes agreed ... in a very geeky manner I can normally tell you what synth is played in a track. Not so with modern S&S synths but definitely older tracks using analogs.

Always thought [the SCi T8] sounded like a "lesser" Prophet (more like a Prophet-600?) But as a "major" synth, I put it in the list anyway. Nice touch-sensitive keyboard. ... I still liked it. :-)

I have never owned a T8 but it is on my list "to own" sometime... I did own a MIDImini and the velocity mod worked so well that the synth just sounded leagues above my Model D (Which sounded fantastic with a few of the RMS modifications such as soft clip distortion). Having played the T8, that's how I remember it... not a great sound engine but a pleasure to play through the velocity and aftertouch on the great feeling keyboard... a players synth just like the Chroma.

I never really think of the Chroma in comparison with any of the digtals you mentioned. Considered a Synergy once, but couldn't program it without a GDS.. a pretty expensive preset machine. Still have a TX-7 module (program it via MIDI), but I was never a very big DX fan. My favorite DX-type sounds are "chiffy" sorts of sounds (e.g. Jefferson Starship's "We Built this City").

Not specifically talking about sound, more like character... it stands out like the other synth listed did, it brought something to the analog realm that other analog polysynths missed.

Hmmmmmm... I had more problems with my Chromas than any other machines I ever owned. (but it was worth it). It's easily more delicate than any other beast I've used. Had the least problems with Rolands, and, interestingly enough, I never had problems with the Kurzweils.

Yes... I can safely say everyone on the list has had some problems with their Chromas over the years... I had all mine restored with new power supplies last year and they are rock solid and now there is enough information on the web to be able to fix-up voice cards so all-in-all I think it's a very sustainable synth. I was referring to the substantial build of the Chroma, to me it's the difference between a plasticy Juno 106 and a grand piano.

Tom Klepacki [21030025] · Tue, 14 Nov 2006 12:38:16 -0500

...Had the least problems with Rolands, and, interestingly enough, I never had problems with the Kurzweils.

Agreed. Roland has always made a product that will always work. Like a Peavey amp. (May not sound good, BUT... it will always fire up on any gig...)

However, I swore off Roland years ago, because they always left a feature or two out of their current offering. Which was later added to the next board. (Which was missing something for the next go-around. Grrrr.)

I play a Korg out now. Rock-solid dependable, and not lacking features... Used it for years. I used to kick L.H. bass using a (Univox) Korg Mini-Korg K-II. 1973. Sorry I sold that synth. Fat, analog bass... I played it thru a pre-CBS Dual Showman amp, with 2 bottoms (4x15 JBL D-140's). That combination moved air in a night club.

The K-II had a slider-filter that you could emulate a (pseudo) man-woman spoken conversation, in combination with different key notes, slight portamento, and a volume pedal. Fun. We used it as a 'stage bit' between the guy guitar player, and the girl singer. They'd act out a conversation/ arguement, and I'd provide the synthetic voices. Kinda like a silent movie piano player. Miss dem days!

The Chroma was a rip with the inverted keyboard function. I'd tell someone that I played so well, that I could play upside down/ backwards.... And stand in front, and take a request. And play backwards. (But, in reality, frontwards! Except for the black keys, but you could learn to invert them...) But, I'm sure all you Chroma owners have done that, right?

....I was referring to the substantial build of the Chroma

A word of advice. If you ever play on a steamship, take your Chroma. If the boat sinks, you could always use the Anvil case as a raft! (The 'Titanic' musicians didn't have a chance atop a violin case!)

Jesper Ödemark [21010135] · Tue, 14 Nov 2006 19:35:47 +0100

However, I swore off Roland years ago, because they always left a feature or two out of their current offering. Which was later added to the next board. (Which was missing something for the next go-around. Grrrr.)

Being a sucker for analogue monophonics I started out with the cheaper stuff in my student days and have then sold off and traded for bigger and better models. That's what happened with Yamaha; starting with CS-5, getting CS-15 (still thinking it a lot of bang for the bucks) and now having a CS-30. Korg; MS_10 to MS-20 (getting another MS-10 'cause I missed it so though). Moog; Rogue -> Taurus 2 (same I know, but cooler) -> MiniMoog etc. In the Roland stable though I started my entire analogue "career" with an SH-09 so that I'm keeping even though I've moved from that (and another 09) -> SH-101 -> SH-1 -> SH-5. Rolands kicks ass when it comes to sturdyness and stability. I have had a Juno-60 which I hated and a JX-8P which I hated even more. But they always worked and they kept their tuning like a good wine it's taste...

Regarding the Chroma I'd not take that on tour and it's not the size nor the rareness, it's that I wouldn't trust it. There's something about the feeling about this girl that make me keep her locked up at home. ;)

....I was referring to the substantial build of the Chroma

A word of advice. If you ever play on a steamship, take your Chroma. If the boat sinks, you could always use the Anvil case as a raft! (The 'Titanic' musicians didn't have a chance atop a violin case!)

Last time I moved the case around in our storage room I never thought of it as light-weight. ;)

Bob Brenenstuhl [21030894] · Tue, 14 Nov 2006 17:06:17 -0500

[Chroma on eBay]

Hey, I just noticed a Chroma on Ebay auction # 180051047188 I can't afford it, but it sounds like a good deal to me! Enjoy!

This is Chroma 21030348, new to the registry and purchased by Richard Willoughby. Pictures from the auction:

New feature requests for CC+

David Clarke [21030085++] · Sun, 12 Nov 2006 15:41:46 -0500

This note follows up to the "New feature requests for CC+" thread started back in September.

We are all familiar with the user-interface of the Chroma, and we probably all have experience on other synths about how good (or bad/inaccessible) certain features can be.

Since most (all) of the users of the CC+ board are from this list, it seems to make sense to have the newly proposed features defined here (cooperatively). In that way, everyone (or at least the majority) believes the feature/plan is good. [There's no benefit if Sandro or I attempt to implement a feature that is unwanted, or is convenient only for one of us to use.]

We can give advice about whether something is physically able to be implemented, but beyond the nuts-and-bolts of the implementation, it would be best if the group comes to consensus on what is desired and how it is to be implemented.

To trigger discussion, here's some questions in terms of the idea of the Random/Randomize patch generator:

• Should all parameters get randomized or should some never be randomized (e.g., volume level, output port, etc.)?
• If only some parameters should be randomized, should this be a fixed set - or should the user be able to specify which ones?
• If the user is to specify which ones, what is going to be a good way to do that? (keeping in mind that we have to deal only with the buttons that currently exist on the Chroma)
• Should the parameters get 'truly' randomized - or should they only move a maximum of a fixed percentage away from the current value in the patch?
• What's the best way to trigger the 'randomize' feature? A set-split combination? a foot pedal? a single button, once in 'randomize mode'?

In terms of some answers/notes to the other ideas originally suggested:

Wider range on LFOs - the closer to audio the better.

It is unlikely that you could get too much faster than it is today without hardware modifications to the voice cards.

The exact item which makes the Chroma flexible is also exactly what limits this parameter. Specifically, the LFOs are not routed in hardware; rather, they're generated in software (there's no free-running LFO oscillator in the Chroma - the LFO function is a software construct.)

What this means is, the upper frequency limit for the LFO is related to how long it takes the processor to calculate all the modulation values for a particular channel/voice and then get back after updating all the other channels to update the LFO value again.

The main processing cycle-time in the Chroma is 1024uS. Considering there's 8 channel boards - that gets your max. (Square) LFO rate to be just over 100Hz.

Finer resolution on envelope parameters (0-63) - useful on the fast end if the limiting caps were removed.

Probably possible.

It wouldn't be a small change as there's a lot of items which are impacted - such as patch structure, internal storage structure, etc.)

More filter resonance levels (might be a DAC resolution issue though - haven't looked at a schematic)

Not directly possible.

The 8 resonance levels are controlled via 3 binary inputs on each voice card. Providing more levels would mean changes to voice-card hardware.

There might be some interesting things that could be done if the resonance levels were modulated. For instance - to try to get a level between "5" and "6", perhaps the system could be set up to be "5" on one cycle, "6" on the next, "5" on the next, and so on. I'm not sure what this would sound like - but it might be worthy of some future investigation.

New keyboard polyphony expansion modes with Expander - spill new note requests to Expander when all channels are in use.

Probably possible.

LFO Speeds and envelopes derived from MIDI Clock. (1/4, 1/4t, 1/8, 1/8t, 1/16, 1/16t, 3/16, etc...)

Probably possible.

The resolution would likely be limited by the software update rate noted above.

Olli [21010284] · Wed, 15 Nov 2006 12:10:11 +0100

hi david,

as far as i am concerned the wish-list is pretty short.

above all comes the alphanumeric display for the parameters.

then i would say resonance resolution. i find the idea of modulating the resonance very interesting, not necessarily in itself but as it represents perhaps a way around the low parameter resolution. in the Xpander, it allows you to acheive very precise resonance settings despite the 63 step resolution. you just route another mod source to the reso, fix it at one level and play with the mod intensity to acheive additional reso settings as the mod intensity simply adds to the setting of the reso parameter. very cool. if that were possible, that would be incredible.

then, there is the LFO sync, which would be cool, especially for filter open/close to be synced to the length of one ore more patterns so no need for lightning fast sync (so 2/4 or 8/4 rather than 1/16) .

to me, these are the most obvious and the ones that would add most value to the synth OS.

i hope i don't hurt any feelings but, while nice, a randomizer function doesn't add any intrinsic value to the synth itself, thats why i would give it very low priority.

thanks for the great work that you guys do!

Mal Meehan [21010182++] · Wed, 15 Nov 2006 11:33:32 +0000

Hear, hear... I second that.

1. Alphanumeric display
2. Increased Resonance resolution
3. LFO sync

I find the idea of a random function to be of no real use... given that it's hard to get inside the programming of the Chroma (like reading a newspaper through a letter box) I think it would only infuriate me more as I would then have to go through all the parameter functions to find out what was "randomised", to find out how the new patch was made.

Better to read the newspaper through an open door!

Tom Moravansky [21030431] · Wed, 15 Nov 2006 06:48:03 -0500

Support for an alphanumeric display. That's all.

Randomization is an extremely low priority;

LFO, resonance resolution - don't care; leave the Chroma as a Chroma and just make it easier to use.

Since we aren't constrained to a pre-defined LCD size, maybe give some serious consideration to something other than 20x2 or 40x2 to make displaying some of the info more clear (algorithm for example).

In addition, give some thought as to mounting options. In my case, the best place would probably be in a small slanted project box that sits on top. Is it possible to mount the display somewhere on the front panel? (yes it would mean cutting through the panel, but still, it may be the best place for some folks).

Olli [21010284] · Wed, 15 Nov 2006 12:57:15 +0100

OK as we are free to give ideas: i was wondering : a REALLY cool feature sometimes in the future would be to create a mode which makes it easier to produce layered sounds than with the link parameter. i.e. link two voice cards together set one to one output and the other one to another for stereo and then edit them either together or seperately for subtle changes once the basic sound is produced. one would have to think a little further how this mode would be ideally structured to make editing as intuitive as possible. but wouldn't it be cool to have one mode with four oscs and four filters at your fingertips?

Olli [21010284] · Wed, 15 Nov 2006 13:26:19 +0100

sugestion "2 voicecard sound"-mode

actually there is something similar in the waldorf wave you can link two programs together and chose if you edit them simulaneously or separately and then you can detune them without having to go to the VCO section. very handy for very broad stereo sounds. it would even be easier if you didn't have to link two separate and independent programs together for that, as there is always the risk that you destroy the layer sound if you edit just one program forgetting that it is part of a multi setup. it would be easier to link them up in a separate mode, and save them together. that shouldn't be too difficult, no? but that would be truely awesome.

Jimmy Moyer [21030184] · Wed, 15 Nov 2006 15:30:38 -0500

1. Alpha display
2. Patch naming. Maybe even add tags for organizing.
3. LFO sync
4. More complicated envelopes. Though maybe not. I am of the thought to to not change things that structurally change the sound. Maybe this is one of those.

And though an alpha display is a no-brainer these days, just a note about programming and a small LCD display. I'd expand the analogy already given and say that programming a Chroma standalone is like reading a newspaper through a letter box, but the paper is in another language and you have to look up most of the words. A small display eliminates the language lookup. The letter box still remains.

A fix for the letterbox problem seems beyond the scope of th CC+ project unless the CC+ could drive a video monitor or an LCD panel large enough to show all the parameters.

I still use an ancient 386 running DOS and my full-screen Chroma front panel program. The Chroma is the easiest thing in the world to program if you can see all the parameters. Once the single display issue was solved, I really don't find myself wishing for a knob box.

Mal Meehan [21010182++] · Wed, 15 Nov 2006 20:44:40 +0000

James

What's the dos program that you have and how can I get a copy?

Chris Ryan [21030691] · Wed, 15 Nov 2006 16:12:34 -0500

What's the dos program that you have and how can I get a copy?

See MS-DOS Editors & Librarians: DOS Chroma Programmer.

Dave Bradley [16330135] · Wed, 15 Nov 2006 18:17:00 -0600

RE: random patch generator - a couple of options, one for total randomization, the other for randomizing all but a fixed list would be sufficient for me. Priority - low

RE: more env resolution - snappier envelopes and the ability to control them better would be a big sonic improvement to the Chroma, and would remove one of its big detractions. Priority - high

RE: faster LFOs - I knew these were software but assumed that with faster processors the routine could be sped up.

RE: more resonance resolution - so all we need is a voice card v. 2, right <g>?

Jesper Ödemark [21010135] · Thu, 16 Nov 2006 07:40:29 +0100

computer editing of the Chroma

I still use an ancient 386 running DOS and my full-screen Chroma front panel program. The Chroma is the easiest thing in the world to program if you can see all the parameters. Once the single display issue was solved, I really don't find myself wishing for a knob box.

But is that real-time? I mean, if you change some parameter, does that show up immediately on the screen and if you change something on the screen (guessing that that is possible too) is that transferred to the synthesizer on the double?

The problem I have had using the Kirschnig Chroma-Editor for Atari is that it lacks all that. You have to fool around and then dump the entire patch either way to hear or see the result. Not very user friendly, then I'd rather program in the dark in a way.

My wish-list for the CC+ upgrade comes when I've read all the postings this far. :)

Michael Salmon [21030155] · Thu, 16 Nov 2006 06:58:12 +0000

Re: computer editing of the Chroma

question on the chromaknob, was its design ever made available to the public?

Jesper Ödemark [21010135] · Thu, 16 Nov 2006 08:08:34 +0100

My feedback *annoying sinewave heard* on the future upgrade bench:

To trigger discussion, here's some questions in terms of the idea of the Random/Randomize patch generator:

My limited experience with random patches (Jupiter-6 with Europa-mod tested and my OSCar which goes into that mode if the contacts between analogue and digital board is dirty) ;) tells me that it's seldom of any use. On the OSCar you get 36 randomised sounds and maybe 1 or 2 is of any use. The rest is low frequency noise, annoying bleeps totally uncontrollable from the keyboard or midi, almost silent thumbs and the like.

So if there should be a random generator. Avoid randomisation of volume and other parameters you'd rather control yourself. It's OK with one, but I'd rather build sounds from scratch.

• If the user is to specify which ones, what is going to be a good way to do that? (keeping in mind that we have to deal only with the buttons that currently exist on the Chroma)

I'd go for an "exclude these-option" and then you could tap the parameter buttons to exclude.

Wider range on LFOs - the closer to audio the better.

Amen! Maybe with a feature to go back to original Chroma limits. I know I found it annoying on my modified TR-606 that there were no way to get the original cheesy sounds without twisting knobs and go by ear. I know why of course, but in this case I think it would be easier. Tell me if I'm wrong. Also, you can never have too slow LFO's either. ;)

Finer resolution on envelope parameters (0-63) - useful on the fast end if the limiting caps were removed.

Probably possible.

Finer resolution is always good. Especially with parameters that you control in real time, for example cutoff and resonance. Regarding resonance I couldn't agree more with other posters that more steps are needed and that that is the weakest parameter there is in the Chroma with just those eight steps. I love sounds where the resonance is on the edge of self-oscillation. It's totally impossible with just eight steps.

The 8 resonance levels are controlled via 3 binary inputs on each voice card. Providing more levels would mean changes to voice-card hardware.

Damn! :(

There might be some interesting things that could be done if the resonance levels were modulated. For instance - to try to get a level between "5" and "6", perhaps the system could be set up to be "5" on one cycle, "6" on the next, "5" on the next, and so on. I'm not sure what this would sound like - but it might be worthy of some future investigation.

Sounds quite cool. Like a LFO-modulated resonance I take it?

LFO Speeds and envelopes derived from MIDI Clock. (1/4, 1/4t, 1/8, 1/8t, 1/16, 1/16t, 3/16, etc...)

Probably possible.

That sounds like a splendid idea.

Regarding the display issues despcribed by other users I don't care. I think the little "letter box" is OK and my plan with the CC+ has all the time been to add a knob box so I personally don't see the use of a screen.

I came to think of some kind of "group patch circle" when I looked at my Mono/Poly. There you can set up the four oscillators with different waveforms and volume, tuning etc. Then you can let the MP4 step through the voices when you play a melody or let the arpeggiator step when in poly-mode. Couldn't this be done on the Chroma? I don't mean for the fuxxed up stuff I tend to go with on the MP4 but for more subtle changes the the stuff OH described when stereo panning. Group for example four patches and then let the Chroma step through or randomly choose one patch with each new key pressed. This probably works best when it's used as a monophonic synth but I sure think it would add a lot of "human feel" and "organic touch".

Did anyone follow my train of thoughts? Am I too far out in the wilderness now?

Jesper Ödemark [21010135] · Thu, 16 Nov 2006 08:14:16 +0100

Re: computer editing of the Chroma

question on the chromaknob, was its design ever made available to the public?

I think it's semi-official. I don't know if it made it onto the site, but I at least received a schematic though not all the code. I was promised the code if I built the knob stuff first 'cause it's such a huge project. :)

Before attempting that I plan to go with my CC+/Doepfer Pcket Dial combo first and see if that works out OK...

Michael Salmon [21030155] · Thu, 16 Nov 2006 07:50:29 +0000

Re: computer editing of the Chroma

yeah the expansion board looks awesome, but i still would love to hand tweak all the parameters on the fly. that feature is really important for certain types of expression. i guess ideally i'd build a CEB for midi and a chromaknob, but the chromaknob details aren't online.

so i guess im just wondering if when smart ppl in the community start hacking great ideas, can they put it on sourceforge or something? assuming it's not for profit of course.. but for the chroma that would be silly :)

david or other chroma hackers, if you're reading this feel free to contact me if you like the idea of open sourcing projects and would like any help at all.

Jesper Ödemark [21010135] · Thu, 16 Nov 2006 09:22:27 +0100

Re: computer editing of the Chroma

You want exactly what I want. So when the CC+ here and installed I'll start looking into configuring the Pocket Dial to do the work as I want it to. As mentioned before, I'll keep the list posted with the progress/regress...

Did anyone snatch any of the Chromas in the VEMIA auction BTW? I think they sold quite cheap.

Peter Forrest [21010096] · Thu, 16 Nov 2006 09:55:05 -0000

Re: computer editing of the Chroma

I agree that CC+ with knobs is the really exciting prospect.

One VEMIA Chroma is on its way to a successful pro musician, and I'll certainly tell him about the forum. The other two, amazingly, didn't sell, and while one is possibly spoken for, the other is not.

Considering they have been thoroughly serviced by Roy Paynter, a price under a thousand pounds would seem a really good deal, but there we go.

If anyone wants to inquire about them, please email me urgently, as I could possibly collect one or both in the next couple of days.

David Clarke [21030085++] · Thu, 16 Nov 2006 19:46:33 -0500

Re: computer editing of the Chroma

question on the chromaknob, was it's design ever made available to the public?

I think it's semi-official. I don't know if it made it onto the site, but I at least received a schematic though not all the code. ...

The schematics for the box are not on the site - but it is a straightforward/traditional implementation that is similar to what is done in most of the older synths with knobs (e.g., analog pots are fed into analog multiplexers. The specific pot is selected under CPU control - and the position of the knob read).

There have been a couple people who have approached me over the last couple years looking to build their own knob box. I have sent those people a copy of the schematics and have indicated that I'd be willing to assist them if they tried to implement. To date, I'm not aware that anyone has actually tried to build one.

Given that there's still a few people that get in touch about the box every year, I haven't totally ruled out the possibility of making up a few - but nothing is currently planned.

While it wouldn't necessarily fit as nicely, it may be ALOT cheaper to buy an old 486 computer with VGA, and then use the new patch editing capabilities in the CC+ interface and build a MIDI based editor with a standard PC program (SoundDiver/Cakewalk, etc.)

You wouldn't necessarily have a knob for each function - but as has recently been discussed, you would have the flexibility to see all the parameters simultaneously vs. only looking at limited information at a time on a smaller display.

(Cost-wise, you'd pay just about as much for a stand-alone 2-line display as you would for a used VGA monitor!)

Rob Vandivier [21030396] · Thu, 16 Nov 2006 20:33:47 -0500

Re: computer editing of the Chroma

If a box were available Id buy it. Ill never get around to making one in this life.

Michael Salmon [21030155] · Fri, 17 Nov 2006 02:19:31 +0000

Re: computer editing of the Chroma

yeah it makes sense, most of the work is just being accurate with so many connections. if you dont mind please send me the schematic when you have an opportunity, if nothing else im curious and interested

Jimmy Moyer [21030184] · Fri, 17 Nov 2006 00:00:16 -0500

Re: computer editing of the Chroma

But is that real-time? I mean, if you change some parameter, does that show up immediately on the screen and if you change something on the screen (guessing that that is possible too) is that transferred to the synthesizer on the double?

The problem I have had using the Kirschnig Chroma-Editor for Atari is that it lacks all that. You have to fool around and then dump the entire patch either way to hear or see the result. Not very user friendly, then I'd rather program in the dark in a way.

The PC display does update in real time. If you're changing patches the Chroma sends a message.

For changing parameters, the PC keeps querying the Chroma repeatedly for the current program parameters and updates the display. This adds a lot of MIDI traffic which you might not want if sequencing, for example, so you can turn the parameter polling on or off. (BTW, this program is a decendent of one written for a CP/M PC with a hand-build Chroma parallel interface. The business of polling for a parameter change was not needed as the Chroma interface will send a message on a parameter change.)

All editing is via the Chroma front panel and not the the PC.

Jesper Ödemark [21010135] · Fri, 17 Nov 2006 07:55:15 +0100

Re: computer editing of the Chroma

There have been a couple people who have approached me over the last couple years looking to build their own knob box. I have sent those people a copy of the schematics and have indicated that I'd be willing to assist them if they tried to implement. To date, I'm not aware that anyone has actually tried to build one.

I started the planning and then the CC+ turned up and I left even the planning. ;)

You wouldn't necessarily have a knob for each function - but as has recently been discussed, you would have the flexibility to see all the parameters simultaneously vs. only looking at limited information at a time on a smaller display.

A knob for each function is the coolest, but not cost effective. I looked at the Doepfer Drehbank before settling with the Pocket Dial. Drehbank has 64 knobs and Pocket Dial "just" 16 arranged in four different banks. If all goes according to plan (like to mention this all the time since I'm not there yet) I'll program mine to have bank 1 control control-, bank- and sweep-settings (button 1-12), bank 2 control the envelopes (button 13-25), bank 3 control pitch- and waveshape-settings (button 26-36) and bank 4 control cutoff- and volume-settings (button 37-50).

Here's the data and pics of the Pocket Dial if anyone cares to check it out (no, I'm not sponsored by Doepfer): http://www.doepfer.de/pd.htm

They're sold out but Ebay and similar sites are flooding with them and Doepfer even mentions that their german representative might have a few units around.

With 14 knobs to spare maybe there is stuff to implement that's currently under no control (for example future CC+ upgrades).

(Cost-wise, you'd pay just about as much for a stand-alone 2-line display as you would for a used VGA monitor!)

2-line displays can always be ripped from vicious digital synthesizers! *mohahahaaaa* ;)

Bob Brenenstuhl [21030894] · Fri, 17 Nov 2006 12:08:36 -0500

Regarding the display, I think the one provided on the Chroma is sufficient, especially if you had access to all the parameters with a knob box or other external means. (Laser surgury is coming way down in price, and your local doctor has been buzy gaining valuable practice the last few years) The only thing I would wish for is mabey a led to indicate the speed of the lfo. I was thinking about it, and realized you would need one for each program in a link, then I was thinking mabey the edit A and edit B leds could be made to flash with the lfo speed? As far as I'm concerned, that would be more useful then knowing what number the setting is set to. (Though knowing the numbers is definetly important so one can be set to a number that divides into the other.) Let me know what you think.

Dave Bradley [16330135] · Fri, 17 Nov 2006 11:20:37 -0600

I don't want numbers, I want alphanumeric readout of the parameters - instead of the Chroma telling me that kbd algorithm is set to 4, I want a display to say "All Chan Mono".

Bob Brenenstuhl [21030894] · Fri, 17 Nov 2006 12:47:58 -0500

That would be the tits! I obiviously didn't understand. Luckily I have the "poster" with the key on it, but that would be a real pain to use in a live setting. I've been trying to memorize the different "codes" but it's tough, and the less used functions are going to take years that way. Good idea! Anything that lets you jam more and think less (about things other then what your playing) is what I'm looking for.

musicforairports · Fri, 17 Nov 2006 08:02:04 -0500

Dave's knob box

I would buy one as well. Deposit in hand and ready to go to Dave if he so chooses one fine day.

I think a good design benchmark would be similar to this box for editing the Ensoniq: http://home.netspeed.com.au/aistorm/esqm.html

Perhaps with a cheery finish to match the Chroma. Something that could mount at a angle or be used on a lap.

Tom Hughes [21030251+] [21030251] · Fri, 17 Nov 2006 08:49:53 -0500

So, are we starting a knob box list? Count me in.

Go to next message in thread, December 2006

DIY solution for a potentiometer interface for the chroma (or other synths)

Daniel Benoit [21030109] · Thu, 16 Nov 2006 21:00:31 -0500

Regarding a midipot box for the Chroma, this is the easiest solution for even the non electronic "geek".

this is one exemple:
http://www.ucapps.de/midibox64.html

this is the base address:
http://www.ucapps.de/

To You order your pre made PCB and to order you parts:
http://www.avishowtech.com/mbhp/buy.html

I have built a 32 channels "fader" to midi converter with my students to "retrofit" in a "NEOTEK" Series II audio mixer,

The PCBs where assembled in a few hours. The hardest part for the students regarding "how" to programme the main circuit was to read the english instructions....(we are in Quebec...)

Once evey thing was figured(using the windows software to map the right midi controller to each faders)it took 10 minutes to have the fisrt pot outputing some midi data when we moved a pot on the mixer.

I have a spare midi CPU board and analog to digital board. I could "pre program the cpu to the correct midi conrtoller(or sysex values) to map the standard chroma parameters. I could leave the code available on the chroma site as long as no body makes money out of it....

Take a look at what some people have built whit this project
http://www.ucapps.de/gallery_midibox64.html

Daniel Benoit
With a "project" Chroma in Montreal
(retrofited left hand controler from a minimoog...)

Michael Salmon [21030155] · Thu, 16 Nov 2006 21:00:31 -0500

that is really neat. you know what actually might sell enough to make a small business? a midibox customized to look/feel like specific old synths, with software to auto-configure them with their soft-synth versions. in particular the 2600, minimoog, prophet 5, etc. but a midibox for the chroma controls would be neat, but nothing beats the chromaknob!

Jesper Ödemark [21010135] · Fri, 17 Nov 2006 07:59:19 +0100

I have a spare midi CPU board and analog to digital board. I could "pre program the cpu to the correct midi conrtoller(or sysex values) to map the standard chroma parameters. I could leave the code available on the chroma site as long as no body makes money out of it....

Please do - that is exactly what the Chroma community needs! If I get around to solving my mapping issues I'll gladly share too...

Jesper Ödemark [21010135] · Fri, 17 Nov 2006 08:03:34 +0100

If I'd _make_ a midibox for the Chroma based on the stuff at http://www.ucapps.de/ I'd sure would make it as thin as possible, but wide so that it fits on top of the button section of the Chroma with one button at exactly the same position as the button below. Then it would get wooden end cheeks and the same colour theme as the Chroma. Or why not make it a Halloween knob box while at it?! ;)

Martin Pavlas [21030450] · Fri, 17 Nov 2006 10:59:42 +0100

Hi,

Well, I am planning to work on knob controller for my chroma this winter. Actually, I bought my chroma with this project in mind. As David said, the electronics itself is rather simple (I would like to use atmel processor possibly with i2c bus for pots/switches). It's not a problem.

At present, my major issue to put together some specs for the project. Here is short list of what I am thinking about:

1. whether all parameters should have a knob / switch or if it should be only a subset of them
2. if I should use pots of all parameters or some of them will be done with switches
3. If it should support midi interface too (not only chromaface)
4. come up with some decent layout of the knobs/switches
5. have there a 'preset' button (as it's on prophet 5)
6. have there a possibility to manage parameter for both channels with one knob when it's needed.
7. have there some sort of modulation source (lfo/s&h) that could be used to modulate stuff (anything) directly in knobbox - for example to send s&h to resonance.

etc etc

If anybody has ideas or remarks I will definitely listen to it and I will be glad to give/share outcome of my work to anybody who is interested in that.

Important thing to say though is that I've been rather busy lately, ie. this project won't go really fast.

and yeah ... the front panel should defininely match chroma's style cos it's just gorgeous :)

Olli [21010284] · Fri, 17 Nov 2006 11:38:28 +0100

concerning the amount of knobs, i humbly suggest to somehow sum it up.

i.e. only implement them for one channel and then switch channels or create something like on the xpander with a couple of softknobs and different pages say one for the oscs end filter and one to control the envelopes.

IMHO this is the most elegant solution and keeps the workload for soldering and designing a PCB and box to a relative minimum while offering a tidy and ergonomic interface. i think, six knobs and a couple of buttons should do it.

and then, add some intelligent DISPLAY, maybe even a large one that shows all the names and values of the relevant parameters of the edited page, so, we could avoid changing the hardware on the chroma itself. but i don't know it the CC+ would support this...

Rob Vandivier [21030396] · Fri, 17 Nov 2006 08:34:53 -0500

This one looks like it has enough knobs :

http://www.midibox.org/midibox_gallery/greg_s1.jpg

Martin Pavlas [21030450] · Fri, 17 Nov 2006 22:04:14 +0100

yes, I was thinking about that idea too. Ensoniqs have something like that - pages + soft buttons + large display - and it's really easy to work with it. Attached you can find a simple idea of page driven interface with 8 or 10 knobs.

Here's some explanation:

Page select

They can be used to choose the page you want to work with. Active page is indicated with LED

After pressing a page select (up to) eight parameters will be displayed on the display. Each linked to a button and a knob.

Pages are collections of parameters. I tried to keep it as it is on Chroma's front panel. Some of them were combined (for example 'glide & pitch')

'Custom' page is a collection of parameters defined by user.

Display

I saw there are some 240x64 displays. It should be sufficient for 8 to 10 parameters. Every parameter would be displayed by using its name. Next to it (underneath / above / whatever) would be a value of the parameter. It would be displayed as text wherever it's possible.

There's a problem with 'cutoff' page as it has 9 parameters in total. Thus, does not work with 8-knobs idea.

Rotary encoders - knobs

knobs to change the value of corresponding parameter. What parameter is being changed depends on what's displayed on the display. The value (text) on the display is changing instantly when the knob is turned.

Channel select

defined if knobs are affecting parameter for channel A, B or both in the same time. LEDs are used to indicate what is active.

Read button

pressing this button will copy current patch from chroma to knobbox (has no name yet)

Parameter button + Parameter select

When 'custom' page is selected one can choose a parameter for given knob by pressing corresponding 'parameter-button' and turning 'Parameter-select' knob in the same time. Name of the parameters is showing on the display as the 'parameter-select' knob is being turned.

It's just a rough idea. Pages would need some more thinking. There could be possibly more 'custom' pages (that could be selected with 'parameter-select' knob. etc.

Does it make sense? any comments / remarks? As I said, my major trouble is that I don't know what path to take. dedicated buttons or something like this.

I don't know if the attached image will get through the mailing-list. If not, you can find it at http://www.netsafe.cz/knobby.png [link obsolete by 2009]

Olli [21010284] · Sat, 18 Nov 2006 00:22:05 +0100

exactly what i was thinking of, martin!!

this thing looks great! so neat! a programmers dream and it stays tidy. standing ovation!!

Olli [21010284] · Sat, 18 Nov 2006 00:26:16 +0100

I don't know if the attached image will get through the mailing-list. If not, you can find it at http://www.netsafe.cz/knobby.png

the only thing about this is that i don't understand what you need the parameter buttons and parameter select encoder for.

but it's late and maybe i didn't get something obvious... lol

Daniel Benoit [21030109] · Mon, 20 Nov 2006 00:05:39 -0500

I will work on a midibox "chroma" version

This is a layout of a pot panel configuration that would fit directly on the chroma's top, that would be exactly the same whith as the program switch section

The "signal" flow is almost... like a standard synt layout.

Daniel Benoit [21030109] · Mon, 20 Nov 2006 00:11:20 -0500

Oups forgot the layout file

Dave Bradley [16330135] · Sun, 19 Nov 2006 23:22:32 -0600

Re: Oups forgot the layout file

No Wave Mod Depth? Looks like you are one knob short.

Daniel Benoit [21030109] · Mon, 20 Nov 2006 01:15:02 -0500

Re: Oups forgot the layout file

modified with wave shape mod depth...

Dave Bradley [16330135] · Mon, 20 Nov 2006 09:04:04 -0600

I really get into this stuff, so one more round of suggestions:

MOD3 DEPTH should be MOD DEPTH on the waveshape.

Filter TUNE should be at the top to match Osc TUNE, then RES in middle and LP/HP at the bottom.

Paul Hackett-Evans [21010094] · Mon, 20 Nov 2006 21:11:37 -0000

This is nice. May I suggest that you alter the layout slightly so that the "Tune" knob is at the same height in the plan for both the Oscillator and Filter section? In descending order, I'd have that column of knobs in the filter section as Tune, Resonance and HP/LP.

I'd also like to see the A and B channels each have their own sections, one above the other.

Olli [21010284] · Mon, 20 Nov 2006 22:16:02 +0100

hi. i am surprised tha nobody seems to have noticed martin pavlas layout idea that seems very neat to me. the only thing i was wondering is what do you need the select wheel and parameter button for?

Martin Pavlas [21030450] · Sat, 25 Nov 2006 19:32:34 +0100

Hi,

sorry for a late reply I was on a business trip for a week...

It prolly looks too digital I guess ;) I like Daniel's proposal too, but I will keep working on the idea with encoders and pages.

As for paramerter buttons and select whell - there is one custom page (there could be possibly more of them). On this page you can have your own set of parameters to be modified with encoders (say some from filter page, some from oscilators, etc) - ie. sort of performance preset. In order to assign a parameter to specific encoder you press corresponding parameter button and turn the select wheel until you find the parameter. (Names of the parameters are showing up on the display as you turn the wheel).

If you guys are interested I can keep you up-to-date on how the project goes on the mailing list. If anybody has any input/remarks/questions, feel free to e-mail me or post it on the list. Also, I might set up a small website for the project.

Olli [21010284] · Thu, 30 Nov 2006 19:02:15 +0100

i AM interested. i think the best thing imaginable would be an Xpander-like UI, as the sound is similar also. i still have seen nothing better than the xpander UI. too many knobs on the A6. xpander is just perfect. you fetch what you want and edit it. period. there is never anything else in front of you than you actually want at the precise moment of editing something. cool

Michael Salmon [21030155] · Thu, 30 Nov 2006 20:57:17 +0000

I would be happy and willing to create a sourceforge project group for chroma hackers if people are interested? there people can post files, project status, source code, designs, etc. copyright and ownership of course can be retained by the author, but it's just a great way to keep track of things over time. of course it's all free to use that website.

See thread Some other non diy solution for a fader box, December 2006.

ORRRR (mostly pointed to Chris), if we had a wiki that allowed file uploads, we could basically do the same thing.. whatcha think?

Chris Ryan [21030691] · Thu, 30 Nov 2006 19:15:37 -0800

ORRRR (mostly pointed to Chris), if we had a wiki that allowed file uploads, we could basically do the same thing.. whatcha think?

Sounds like a great idea. I'll look into it. A friend pointed me to WikiMatrix; does anyone have any experience with wiki software, or can otherwise recommend a wiki that is Web standards compliant so I can fairly easily bend it into shape for the Chroma site?

Dave Bradley [16330135] · Thu, 30 Nov 2006 22:19:01 -0600

http://twiki.org/

We use this at work for a company intranet and it works well.

Go to next message in thread (Chroma Wiki), December 2006

Chroma Knob Slider Cap - Resource?

Uro [21030401] · Sat, 18 Nov 2006 20:18:39 -0800

Wanted to see if this part would do the trick for replacing the knob slider caps on the left side of the unit:

http://uk.farnell.com/jsp/Mechanical,+Office+&+Workplace/Knobs/MULTICOMP/CP-L175./displayProduct.jsp?sku=766756&_requestid=101081

Order number: 766756

If they are the same dimensions, then they are coincidentally the same as on the early E-mu (e.g., Emulator III, SP1200) units.

If not, well, who knows where we can?

Chroma on eBay

Chris Ryan [21030691] · Sun, 19 Nov 2006 19:57:39 -0800

Item #140053945105, Current bid US$500, ends November 26. Tidbits from the description: "One of the first ones still made by ARP ... This model has the boards with ARP Name on them. It has been in storage for several years. Was serviced before being put in storage but you are buying it as is. To the best of my knoledge there is nothing wrong with it but I have not turned it on since it was in storage."

I've e-mailed the seller for a serial number.

Here's the picture from the auction:

Doug Terrebonne [21030114] · Mon, 20 Nov 2006 00:15:46 -0800

I hope he removed the batteries before putting it in storage that long...

Ron Joseph [21030042+] · Mon, 20 Nov 2006 17:29:42 +0000

Just an obseesive note about my favorite compulsion. There are no vents on this chroma's top and the glaring white key is readily seen. I'm going to contact the guy about the parameter #2 just to make sure.

Peter Forrest [21010096] · Mon, 20 Nov 2006 17:42:51 -0000

Wow, that white key is very obvious! Please let us know what he says about #2 .

Ron Joseph [21030042+] · Mon, 20 Nov 2006 18:51:16 +0000

Is there a way to bleach plastic keys that have discolored like those on the early chromas? I know one owner just swapped the entire keybed, but that requires a dead Chroma carcass. Just a cosmetic issue but the white keys do look nicer than the discolored keys w/ white key exclamation point ;)

For those that have worked on various Chromas, are there any differences to the various keybeds. IIRC there were 3-4 different keybeds used. My Chromas action has always seemed excessively noisy. I never understood peoples admiration for the Chroma's keyboard. Mine doesn't seem so great but maybe the type used on mine wasn't as nice.

For more discussion about and mentions of discoloured Chroma keys, see Chroma 21030052/21010135 (March 2006) and Ron Joseph's post in the "Chroma 21010022 for sale on eBay" (September 2006).

Olli [21010284] · Mon, 20 Nov 2006 22:18:21 +0100

"To the best of my knoledge there is nothing wrong with it but I have not turned it on since it was in storage."

what might kept him from turning it on before selling it...?

Peter Forrest [21010096] · Mon, 20 Nov 2006 22:41:18 -0000

fear?

Jesper Ödemark [21010135] · Tue, 21 Nov 2006 13:48:48 +0100

It sure is easier to be honest this way. "It was OK when stored away. Now I haven't turned it on." is better than "I turned it on, nothing lighted up and after a while smoke came out of the vents and there was a funny smell. I ended up in an ER with a ten day memory loss and an implant in the back of my neck."

Jesper Ödemark [21010135] · Tue, 21 Nov 2006 14:02:17 +0100

Drench the white in tea or something for a few weeks. It might solve the problem and all will look like the Roland SH-range instead! :)

I Like the feel and touch of my Chroma keyboard, but there is something "clunky" about it. So if it is this you're referring to as noisy I have that problem too.

jesper - likes off-white

Polaris # 301936

Peter Forrest [21010096] · Mon, 20 Nov 2006 15:53:56 -0000

Well, at the weekend I collected the Polaris that was sold in the VEMIA auction [301936]. It's in remarkable cosmetic condition, seriously (after the dust was cleaned off) near-mint.

Long notes were cutting off abruptly, but I was amazed to find user instructions in the manual to re-calibrate the VCAs via the front panel controls. Even I was able to do this successfully in about three minutes.

The filter goes into self-oscillation VERY abruptly, but I seem to remember this happening with the other Polarises I've played in the past.

Any comments?

It's a very powerful synth, and I did tell the buyer that if he changes his mind I'd be really happy to step in. Otherwise, it's on its way to the Czech Republic in a few days' time. It sold for 375 UK pounds, by the way.

David Gowin [21030611] · Mon, 20 Nov 2006 11:08:28 -0500

From what I remember, the Resonance control was incremented in 7 stages so going from resonance to self osc was pretty easy. Otherwise, yeah, great keyboard, especially if you could get the memory expander kit to up the sequencer/recording storage capability. I have 2 Polaris's (Polari?) as well as a Chroma.

Jesper Ödemark [21010135] · Mon, 20 Nov 2006 17:19:58 +0100

I kept that on my watch list but decided not too... Good price!

Paul Hackett-Evans [21010094] · Mon, 20 Nov 2006 21:17:42 -0000

I'm still looking out for one, too.

Chroma for sale (to the group first)

Kevin Kelley [21030491+] · Mon, 20 Nov 2006 11:25:32 -0800

I have a chroma that is in good physical shape and worked great until the power supply died. I do not have time to repair this chroma due to school and work. I have a MAP 80 switching supply that I will include also all of the tech docs and manuals. The chroma is located in Florida 33701 and I am asking $800 that's what I paid for it when I purchased it. Please hit me up offline at [e-mail address removed] and i can send pics. Thanks

Update on 21010250

Paul Hackett-Evans [21010094] · Mon, 20 Nov 2006 22:49:25 -0000

I'm taking over the restoration of Chroma 21010250, from my friend Pete Riani.

Pete's Chroma was rescued from a rubbish skip at the Newcastle School of Music in 2001. Pete started by sending his power supply to Roy Paynter for service. Unfortunately, Pete became very seriously ill for a long time. He has now recovered, but doesn't feel able to carry on restoring the Chroma. Roy and I will take it on instead.

As with my Chroma, 21010094, I'll work on the cabinet, cosmetics and the keyboard, while Roy will do the electronics. I'll collect the parts of the Chroma from Pete before Christmas and we'll get started.