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ChromaTalk Archives: March 2010

Re: unknown patch cassette

Go to first message in thread, February 2010

August B. Raring [21010148] · Wed, 3 Mar 2010 11:23:58 +0100

August's email seemed to be empty but prompted Jesper's response below.

Jesper Ödemark [21010135] · Wed, 03 Mar 2010 11:30:47 +0100

Same as the one I won. It arrived the day before yesterday but i've been too busy working so I haven't checked it out yet.

August B. Raring [21010148] · Wed, 3 Mar 2010 12:06:56 +0100

Hi Jesper,

I did a quick check of the "unknown patch cassette":

There are about 20-30 single patches, I didn't count them,almost most of them are from the factory presets set 1 or 2,as far as I remember. The modifications made, are that some of them are arpeggiated or for example the release time is altered. The only 3 or 4 patches that seem to be "homebrewed" are unuseful noises, in my opinion.

I think the cassette isn't worth the money I paid for it: EURO 2.60 incl. shipping!

So I'm anxious what you do think about it!

Jesper Ödemark [21010135] · Wed, 03 Mar 2010 12:12:08 +0100

OK, so you bought one too... I'll get back with a review once I've had time to load them.

Chroma Polaris

Rob Belcher [16330123] · Wed, 03 Mar 2010 14:27:57 +0000

Hi guys,

I bought a Chroma Polaris a while back, was supposed to be fully working but its arrived with some issues.

I'm currently considering selling it because i could do with clearing a little debt.

Anyway, the reason for my post, im wondering sonically if the Polaris would give me anything that my Oberheim Xpander and Rhodes Chroma Expander wouldnt give me?

Using the CEM 3374 VCO into CEM 3372 VCF plus digital envelopes im guessing its not going to be a million miles away from the Xpander which also uses those chips.

However i know the chips are not the whole story..

Anyway, if anyone has any thoughts on this, sort of mulling over if i should keep it or sell it..

Dave Bradley [16330135] · Wed, 3 Mar 2010 10:45:06 -0600

I wouldn't see any reason to keep it, if you have Xpander and Chroma already.

David Gowin [21030611] · Wed, 3 Mar 2010 11:53:42 -0500

I would say the Polaris might be a good synth too keep. The onboard sequencer, tempo tap ability, some really interesting sounds can be made, it can sound pretty fat and it is part of the ARP design heritage.

Paul DeRocco [21030230] · Wed, 3 Mar 2010 09:30:40 -0800

Only the Polaris has selective pitch bend. Depending on your playing style, that may be important.

JLCooper ChromaFace Schematic

Chris Ryan [21030691] · Thu, 4 Mar 2010 22:34:09 -0800

This month's site update is an interesting historical/technical footnote. I contacted JLCooper Electronics and to ask if they had any remaining information on their (ancient) MIDI retrofit for the Chroma. Joe Uribe in Product Support kindly wrote back and sent the schematic.

Lars Johansson [21030632] · Sat, 6 Mar 2010 00:07:42 +0100

Now,

if someone could do a clone of the Oberface, I would be very grateful.

August B. Raring [21010148] · Fri, 12 Mar 2010 23:09:49 +0100

very interesting, thank you!

Some time ago I had much trouble with the Chromaface and would have been grateful for the schematics .I changed all IC's that were possible, with no result. Until I noticed that the reason was the power supply!!! Having installed it into the Chroma I had used the Chroma's digital 5V. An external PSU solved the problem.

By the way I found out that the Chromaface-manual on the Chroma-website is missing two pages mainly about "multi-channel vs one channel receiving"(pages 4 and 5). Unfortunately i got no scanner so I can't copy it for you.

I also noticed a possibly bug in the chromaface: If a pitch bend midi signal is all the way down the result is a pitch bend all the way up, a very funny behavior!

Chris Ryan [21030691] · Fri, 12 Mar 2010 19:59:33 -0800

On 2010-03-12, at 2:09 PM, August B. Raring wrote:

By the way I found out that the Chromaface-manual on the Chroma-website is missing two pages mainly about "multi-channel vs one channel receiving"(pages 4 and 5). Unfortunately i got no scanner so I can't copy it for you.

If you send it to me (contact me off-list for an address) I'll scan it and send it back to you.

Werner Schöenenberger [21010114] · Sat, 13 Mar 2010 10:52:33 +0100

This month's site update is an interesting historical/technical footnote. I contacted JLCooper Electronics and to ask if they had any remaining information on their (ancient) MIDI retrofit for the Chroma. Joe Uribe in Product Support kindly wrote back and sent the schematic.

Hey Chris,

this is good news - there will be some people grateful for this information.

Looking for a rhodes chroma

Matt Hillier [21010094+] · Fri, 5 Mar 2010 12:05:32 +0000

Hi guys

just a longshot but if anyone ever has a chroma for sale please mail me

Tim Siefkes [21030850] · Fri, 5 Mar 2010 12:59:20 +0000

Matt,

I am considering putting mine up for sale this year. It'll need some work, not currently functional. Case, pedal, Syntech midi interface and yes even the old original Apple ][+ interface all come with it.

I'm located in Minnesota, so am not sure how we would handle shipping to the UK. Write me back offline for more details if really interested. I responded publicly here in case you don't want one that still needs work, but there might well be someone else who does.

Cubase 5, and CC+

Brent S · Sat, 6 Mar 2010 19:14:25 -0800

Hi everyone, great list and site. I just had 21030607 resurrected and a brand-new installed CC+.

Just so I don't go nuts trying to figure out what wrong here, does anyone have the Cubase/CC+ template working with vista64/Cubase5-32bit (or just with Cubase 5 period)?

Looking at the Chroma and the template setup, both seem to be expecting the same CCs (default CC+ setup), which is good. However,many of the switches in the template (including all for voice B) don't seem to be sending MIDI data (as per the CC+ midi activity light), and the subset that does sends the wrong thing (i.e. glide rate A sends pitch tune A).

The Chroma seems to be working fine, though I'm just a teensy tiny bit worried as the voice allocation display doesn't seem to display the B voices (which I confirmed were playing along with the As). But otherwise the problem seems to be on Cubase's end, I think.

David Clarke [21030085++] · Sat, 06 Mar 2010 23:15:38 -0500

Brent - one of the folks using Cubase with the map would be better to reply in terms of specifics, but I'm guessing that at least one change away from the default/shipped configuration of the CC+ would be required.

Specifically - if MIDI CCs are being used in the Cubase Panel (which I think they are), and if all the parameters are desired to be edited, then you'll want to make sure you're using the 'expanded' MIDI Controllers Map mode vs. the Syntech 'emulation' Mode.

In terms of specifics - that would mean entering [Set Split][36], choosing P18, and then selecting "Cust" (vs. "Cult"). [xref: Configuration Interface & MIDI Support]

Making this change will allow all parameters in the Chroma to be addressable via MIDI CCs.

Brent S · Mon, 8 Mar 2010 11:05:03 -0800

That was it! Thought I checked that, but must of goofed something else up at the time. Works great now.

CPS Kit update

Chris Borman [21030194+] · Mon, 8 Mar 2010 06:32:27 -0500

Hi Folks,

CPS Kit hit a production quality snag at the FSR Flex circuit to Mux board connection so I am going to Revision 2 that will employ the same circuitry and sensor using all rigid PCB. The issue is excessive movement on that junction point would cause one or more sensors to fail and the concern there is handling during customs inspection and installation. The good news is that CPS will be more robust and installation simplified given the sensor array will be on a single rigid 34.5" strip. I will have the CPS Rev 2 pcb in about two weeks.

Luca Sasdelli [21010226] · Mon, 08 Mar 2010 12:38:49 +0100

Hi Greg,

the update is a major one and I guess it would be more stable. Great! I hope there would no problem in shipping such as a delicate PCB...

Luca Sasdelli [21010226] · Mon, 08 Mar 2010 12:40:32 +0100

Greg???

Sorry Chris :)

Peter Forrest [21010096] · Mon, 8 Mar 2010 11:51:18 -0000

It might be worthwhile checking out the packaging requirements for a long thin PCB in advance - could possibly need some specialised packing to insure safety in shipping?

Chris Borman [21030194+] · Mon, 8 Mar 2010 07:05:01 -0500

I have. USPS offers a 38" rigid shipping tube for protection. I've already ordered a couple dozen.

Arun Majumdar [21030348] · Mon, 22 Mar 2010 20:56:48 -0400

Hi Chris,

Thanks for the update. Let me know if there is any small cost differential - I am happy to make sure you're not loosing out - we're a small community and it's important for us to be supportive so please let me know of you need any extra $ going forward.

Chris Borman [21030194+] · Mon, 22 Mar 2010 22:36:53 -0400

Much appreciated Arun and Chroma Community but that is not necessary. Not a big difference, $10/$20 more for domestic/Int. and USPS provides free shipping materials (tubes, doc bags). The next production run will reflect the additional S&H.

The Rev 2 boards are due in next week or so which solve the flex circuitry/connector reliability issue and fixed a couple goofs on my part, so the wait should be worth it. The board house that I thought could, according to their website info, could not do a 34.5" PCB. So to avoid double NRE & production costs for left and right 17.25" sensor array PCBs, I designed a single PCB with the component side for the upper keys, flip it over and the Solder side is for the lower keys and uses the Rev 1 parts (minus the connectors!). See attached Rev 2 design. The two sensors will be mounted to a 34.5" x 1/4" support/spacer to make a single sensor assembly and bring the sensors closer to the contact point. The damper bar on my Chroma is mounted all the way down which is worse case and was not far enough for sufficient contact.

A little joke aside.

Heinz Weierhorst [21010276] · Mon, 8 Mar 2010 20:00:58 +0100

When checking out the MIDI connections of my Chroma the test object was a Korg Poly 800-II. First at all the Poly needs a new battery. Done. Next I made all connections and set the tune-sliders of both synths to center. The result was heavy detuning. So I first checked the Chroma with a strobe-tuner and after that the Poly. The bad part was the Poly. So searching the internet for a service manual. Got it. Looking at the schematic (I hate Korgs schematics) there was a trimpot for tuning-center - but it was at the endpoint. So I set it to middle position and after that the master -oscillator was calibrated to exact tune. Now checking out again and believe me after ours the Chroma needs no auto-tune and stays stable as it's digital counterpart! Okay to be fair the temperature was relativly stable and I've done a lot of work on the voiceboards.

Jesper Ödemark [21010135] · Tue, 09 Mar 2010 10:38:50 +0100

HW skrev:

The bad part was the Poly.

The bad part is _always_ the Poly-800. Why pollute a nice studio environment with a cheap crap-synth like that? Call me unfair, but I really hate it (having owned two over the years).

Now checking out again and believe me after ours the Chroma needs no auto-tune and stays stable as it's digital counterpart! Okay to be fair the temperature was relativly stable and I've done a lot of work on the voiceboards.

That, one the other hand, is great news! :)

Luca Sasdelli [21010226] · Tue, 09 Mar 2010 11:53:50 +0100

Uh,

why call it a crap-synth? Well... it didn't have velocity sensitivity, but it did sound someway. And, okay, there was only one filter... but was it relevant in a typical '80s rock mix? Yes, it used top-level divider, so the sound was terrific "digital"... and if you need a fatter sound, you can double the DCOs; uh, I know, the polyphony fall to 4 voices... this to let you improve creativity and musical genius! Three EGs with four DCOs is a huge implementation, never paired!

I agree... it was a crap :)

Jesper Ödemark [21010135] · Tue, 09 Mar 2010 12:09:56 +0100

Luca Sasdelli skrev:

Uh, why call it a crap-synth?

Let's see below...

Well... it didn't have velocity sensitivity, but it did sound someway. And, okay, there was only one filter... but was it relevant in a typical '80s rock mix? Yes, it used top-level divider, so the sound was terrific "digital"... and if you need a fatter sound, you can double the DCOs; uh, I know, the polyphony fall to 4 voices... this to let you improve creativity and musical genius! Three EGs with four DCOs is a huge implementation, never paired! I agree... it was a crap :)

Spot on! I first assumed you would defend it. *haha*

Don't forget that the great detune (along with all other controls) are stepped in few steps (not unlike the Chroma resonance, though that's a flaw I can ignore when seeing all the good stuff) for state of the art zipper-like sweeps and modulations. And the general build quality with all that plastic. What a design dream come true! :)

Rob Belcher [16330123] · Tue, 09 Mar 2010 11:43:16 +0000

Except for the Prophet VS of course.. 4 DCOS, 3 EG.. Unison, velocity/ aftertouch. :)

Luca Sasdelli [21010226] · Tue, 09 Mar 2010 12:49:15 +0100

Uhm... the Prophet VS had 4 DCO "per voice". Poly 800 had 4 DCO "per instrument" :) (8 DCO if "fat" disabled) Four notes and full stop!

Heinz Weierhorst [21010276] · Tue, 9 Mar 2010 18:02:52 +0100

Why did I choose a Poly 800? Simple because I own one and it has small dimensions and weight. Ideal for moving around. But it's the best way to a youngsters, who's world is digital nowadays completly to show what analog can do! So set the Poly to a similar sound, eight voice polyphonic, switch off the effect section and hold down a chord for a while. It's really boring! Now do that to the auditor with the Chroma. Who will be the winner? O.K. - it's not that fair because the Poly is a little step higher than an electric toy.

Chroma demoed on Ihavesynth

Michael Zacherl [21030253] · Thu, 11 Mar 2010 15:30:25 +0100

I'm sure you know about that ... just in case: Rhodes Chroma Demo - Polyphonic Dream (have yet to read/watch it)

Rob Belcher [16330123] · Thu, 11 Mar 2010 14:36:28 +0000

Hi... Those videos have been on Youtube for a while [see Recordings and Videos]. Still worth a watch. Couldn't believe how close that Mellotron flute patch sounded. Not sure which video that one is in.

Expander etc. For Sale

Chris Ryan [21030691] · Sun, 14 Mar 2010 12:45:01 -0700

Steve Grom, Director of Marketing at Fender during the Chroma era, is selling some of his Chromas and related items:

  • Chroma Expander, USD$2500 includes US shipping;
  • two "project" Chromas that need to be restored cosmetically and electrically;
  • two full sets of channel boards that have been tested (in the Expander) but both units have power supply issues;
  • some power supply parts.

For more details, see For Sale by Steve Grom, November 2009. [Contact information removed.]

Key Scanner EPROM

David Hobson [21030506] · Tue, 16 Mar 2010 10:16:29 -0700

Hello,

I don't believe I ever have posted to the users group before...But I need some help. Does anyone have a key scanner Eprom available out of an old unit that I could purchase, Or does anyone know of where I could find one?

John Leimseider [21030434++] · Tue, 16 Mar 2010 11:44:54 -0600

I can burn them if you need it...

David Clarke [21030085++] · Tue, 16 Mar 2010 19:13:00 -0400

If you know someone that can create EPROMs (in general) then they can use the images available on the site to make a Chroma Key Scan EPROM for you: see EPROM Code and specifically: 3_KYBDSN.obj.

David Hobson [21030506] · Tue, 16 Mar 2010 17:07:55 -0700

Thanks for the replies,

I have managed to find the eprom cods from the chroma cult site and my keyboard now works! Great News!

Thanks for the help

NOS Ivories on eBay

Chris Ryan [21030691] · Tue, 16 Mar 2010 19:32:54 -0700

Item #250597872845, "buy it now" price of USD$150.00, ends March 22. From the description: "It is my belief that these are keys for the Arp Chroma as well as the Rhodes Chroma. I worked at the facility that manufactured the Chromas, when the facility was shut down I acquired a NOS box of ivories, the only two units that were manufactured at this facility was the Rhodes Chroma and the Rhodes 4 voice electric piano. The keys are for one or these units. I have no way to check/measure the actual keys as sadly, my Chroma's are all long gone. Please measure your keys carefully!" There are several pictures with measurements. Can anyone verify these are from a Chroma?

Some of the pictures from the auction:

Chroma on eBay Germany

Chris Ryan [21030691] · Tue, 16 Mar 2010 23:24:50 -0700

Item #150423491382, 10 bids, current bid €336.00, ends March 21. Looking at a translation of the description, it looks like the owner bought it in 1984 but hasn't used it in a long time and it has a few problems--perhaps due to memory loss (maybe a battery problem?). The wood seems to have a bit of foam rot. The Anvil case is included, along with pedals, footswitches, a JLCooper ChromaFace; Performance, Programming, and Service manuals, the brochure, and a few booklets in colours I haven't seen before: blue, yellow, and green. Anyone know what these might be?

Could someone who speaks German ask the seller for the serial number?

A few of the pictures:

Jesper Ödemark [21010135] · Wed, 17 Mar 2010 11:16:36 +0100

I've asked for the serial...

Helmut Segeth · Wed, 17 Mar 2010 16:23:19 +0100

Meanwhile got an answer from the owner. S/N is 21010293.

August B. Raring [21010148] · Wed, 17 Mar 2010 20:42:10 +0100

Andreas Bitterer from Hamburg, Germany, told me that the S/N of his CHROMA is 21010293 and that he intends to register on rhodeschroma.com! The green booklet on the foto is the German translation of the manual, maybe the other colors are other languages? I didn't ask for these.

Jesper Ödemark [21010135] · Thu, 18 Mar 2010 11:13:41 +0100

serial of german Ebay Chroma

Here's serial number direct from the seller of: eBay item 150423491382

"Sure thing. S/N 2101 0293."

But now I see it's already in the registry. A direct sibling of Sandro's Chroma [21010294] and one of the last in the European batch too...

Juicy set of manuals BTW.

Jesper Ödemark [21010135] · Thu, 18 Mar 2010 11:23:58 +0100

August B. Raring skrev:

Andreas Bitterer from Hamburg, Germany, told me that the S/N of his CHROMA is 21010293 and that he intends to register on rhodeschroma.com! The green booklet on the foto is the German translation of the manual, maybe the other colors are other languages? I didn't ask for these.

The blue is also a german version. If I recall correct it's a programming guide or computer interfacing dito. I have to check at home to be positive. My guess is that the yellow is something similar.

Chris Ryan [21030691] · Sun, 21 Mar 2010 10:21:51 -0700

Sold for €2.031,00.

Jesper Ödemark [21010135] · Sun, 21 Mar 2010 17:01:04 +0100

the german ebay chroma sold

2031 EUR... that's a bargain in Europe for that juicey setup!

Midi Patch Dump

David Hobson [21030506] · Sun, 28 Mar 2010 14:37:10 -0700

Hello,

I need some help (boy do I),

I am trying to perform a midi patch dump with my midi interface and "save all" does not send midi data to the midi interface. It has been a while since I purchased my midi interface so I am not sure what kind it is but I know it is a small black box with no name on it and of course the ribbon cable. Does anyone have this interface? Can you tell me how to perform a patch save using this black box...I could send some photos of the Black Box if necessary. I know I did it before because I am looking at three syx files is sysex that I created on the Chroma but my memory is bad and I need some assistance. Like, is there a certain key-combination I need to press to get it to save all?

Thank you for your time.

Chris Ryan [21030691] · Sun, 28 Mar 2010 14:46:03 -0700

It sounds like a Syntech (Chroma Cult) or clone. Have you looked at the Syntech manual?

David Hobson [21030506] · Sun, 28 Mar 2010 18:11:35 -0700

Hello Chris,

I have read the programming manual of the interface and I cannot make heads or tails of it. I may be slow but i just need to know how to save from the chroma to sysex a full patch dump... Please help me as I cannot seem to make sense of what i am reading.

Chris Ryan [21030691] · Sun, 28 Mar 2010 18:53:46 -0700

Take a look at the Loading and Saving Sounds Via MIDI section of the manual.

Ken Ypparila [21030229] · Sun, 28 Mar 2010 21:03:40 -0700

Press "set split" then "48"

Chris Ryan [21030691] · Sun, 28 Mar 2010 21:48:04 -0700

This is in the manual in the section The Special Functions.

David Hobson [21030506] · Mon, 29 Mar 2010 09:46:51 -0700

Hello Ken,

Thank you for refreshing my memory...I was having a hard time pressing 48 because it sticks a bit and i was questioning whether I had all of my faculties together. IT works, love the midi interface.

Specific Chroma problems.

Bruce Sklar [21030660] · Mon, 29 Mar 2010 14:24:44 -0400

I have a bit of a situation.

I replaced the big blue cap in my power supply, and now everything is functioning (it wasn't getting past tune up before) except-

  1. The keyboard or key logic seems finicky- sometimes playing will cause the panel to freeze. I did have it playing fine for a 24 hr period on Saturday.
  2. Store function doesnt work, and all programs are scrambled- No sound until i zeroed all parameters
  3. Arpeggiator functions don't seem to work.

Thoughts?

Paul DeRocco [21030230] · Mon, 29 Mar 2010 18:38:04 -0400

  1. The keyboard or key logic seems finicky- sometimes playing will cause the panel to freeze. I did have it playing fine for a 24 hr period on Saturday.

By causing the panel to freeze, do you mean crashing the system so that it needs to be turned off and on? The only way I can imagine that being caused by playing is if there is some bad location in the EPROM or RAM that only gets accessed when playing.

  1. Store function doesn't work, and all programs are scrambled- No sound until i zeroed all parameters

The Store function can be inhibited by the switch on the rear panel. If that's in the correct state, it's still possible that there is a bad connection from that switch up to the rest of the circuitry. And if the RAM lost its contents, due to dead batteries, powering it up would result in random parameters, not zero parameters.

  1. Arpeggiator functions don't seem to work.

Haven't a clue. However, it all sounds like there are still some hardware problems. You'd have to be really lucky to fix this without proper diagnostic tools and methods, like using a scope to trace through various parts of the circuitry with a good understanding of how it's supposed to work.

Luca Sasdelli [21010226] · Tue, 30 Mar 2010 12:13:54 +0200

Hi Bruce,

did you check the +5V digital after blue cap replacement? All your faults relies on logic, therefore you can begin with its dedicated power check.

The voltage should read +4.90V to +5.10V on chip pins.

Double check battery status, even by cleaning battery holder contacts.

Bruce Sklar [21030660] · Tue, 30 Mar 2010 06:35:49 -0400

Thanks for the response - as always this group of folks is awesome. Yeah, I forgot about the little switch- store function seems to work Yes, the panel freezes, needing to be turned off and on. Luca S. suggested checking the digital 5v voltage, i'll need to get someone techier than myself.

I'm wondering though, if it could be an ageing ribbon cable from the keyboard. I'll see if I can get my chroma club interface fired up to see if and external trigger works better.

Other than that, it would seem if what you were saying was true, the long term solution would be a CC+ replacement?

Paul DeRocco [21030230] · Tue, 30 Mar 2010 11:11:54 -0400

Thanks for the response - as always this group of folks is awesome. Yeah, I forgot about the little switch- store function seems to work Yes, the panel freezes, needing to be turned off and on. Luca S. suggested checking the digital 5v voltage, i'll need to get someone techier than myself.

I'm wondering though, if it could be an ageing ribbon cable from the keyboard. I'll see if I can get my chroma club interface fired up to see if and external trigger works better.

It's always worth checking every connector in sight, in an old piece of equipment. Unplug and replug everything. Even the socketed chips can be pried up slightly and then pushed back down, to ensure that they are making good contact. Do it with the power off, of course.

Other than that, it would seem if what you were saying was true, the long term solution would be a CC+ replacement?

That would "fix" problems on the CPU board, but you could still have problems elsewhere.