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ChromaTalk Archives: April 2012

Midi problem solved

David Hobson [21030506]

See earlier thread question about midi and cc+, March 2012


My midi problem with the cc+ and the syntech interface is solved thanks to the documentation provided on the Rhodes Chroma I need to fix my other problem, learning to read directions.

Refurb project underway

Dave Blees [21030552]

Today I finally got around to replacing the power supply on good ol' 21030552 with one of Luca's [21010226] that I've had sitting on the shelf here for a couple of years, AND I also installed a CC+ card that I've had for almost as long. One of the joys of being rather freshly unemployed is that I finally have time for such projects.

This project went quite smoothly, and as anticipated, everything works perfectly. Thanks, guys! Nice to have some actual useful patches back in the memory again, and even though the machine was functioning notmally before, it was so nice to power it up today and not hear that annoying power supply buzz!

Now that I know this will work, next up is the woodworking part, to fix an EXTREME case of "case rot". A friend in the exotic hardwoods business has supplied me with enough of 2 different woods - Ipe (Brazilian Walnut), and Jatoba - both of which would be appropriate to the project, so I had been considering just cutting everything twice so I could have one whole set of Chroma woody bits made of each wood. (This is provided of course that I successfully make all the cuts without too many wood-trashing errors!)

I am intending to put this machine up for sale once I have it in tip-top shape, so with that in mind, I have a few questions for the group:

  • If I do manage to succeed in creating an "extra" set of wood bits in this process, what might they be worth to anybody?
  • Also, since the original but twice-repaired power supply and the old computer board with Rev14 EPROMS are all in working order and were removed fully intact, I plan to include those as spares if any potential buyer wants them. However, I am assuming that an old original Chroma PSU is probably worth close to nothing. Would that assumption be correct? Should I just throw the old PSU on a trash pile?
  • Since I had had a Syntech MIDI card installed using the "expansion" (#2, formerly blank panel) RS-232 port space, I had to remove that to put in the CC+'s MIDI kit. I understand that the Syntech would function concurrently with the CC+, but would there be any reason to use both other than to retain some possible backward compatibility with software that may address the Syntech? Is there any conceivable advantage to using both?

I'm sure I'll post some more questions soon, plus some pics once I have the new woody bits on. Come to think of it, I'd better shoot some "before" pics tonight....

Chris Ryan [21030691]

I am assuming that an old original Chroma PSU is probably worth close to nothing. Would that assumption be correct?

See the Price History: there was one sold last year for USD$50.00.

Chroma weight with SPSU

Heath Finnie [21030175]

Does anyone know what the weight of a Chroma is with the original PSU replaced with the much smaller Luca SPSU? Curious how much lighter it is.

Luca Sasdelli [21010226]

Hi Heath,

the SPSU kit weight is a bit less than 1kg, this to allow to ship it with minimum costs. The original one should be around 4kgs, I guess (the transformer only is 3kgs).

Re: Tapper Assembly on eBay

Go to first message in thread, March 2012

Chris Ryan [21030691]

On 30/03/2012, at 12:43 PM, Chris Ryan wrote:

Item #300688342078, starting bid USD$19.99, no bids yet, ends April 2.

Sold for USD$19.99.

Zawinul playing his Chroma

Chris Borman [21030194+]

Brian McCully [21030361]

That's awesome, Chris. I saw [Weather Report] with Omar [Hakim] and Victor [Bailey] in NYC at the Palladium during that time (expecting to see Jaco [Pastorius] - but Victor did fine). Great show, and Omar was over the top. Years later I saw Zawinul in Providence RI doing his solo tour, with a Chroma and/or Expander (with lots of Korgs and the vocoder). Zawinul's tech told me (after the end of the show, as the stagehands were packing up) that the Expander was a real pain in the butt to keep functional. Anyhow - thanks much for sharing - it brought me way back in time and was out of the blue. It was especially fun to see the Wayne and Josef clips from their younger years - I wonder if us synth guys like our toys too cuz they're 'shiny'. ;>) -Brian

Re: Last of the CPS Kits

Go to previous messages in thread, February 2012

Werner Schöenenberger [21010114]

Hallo Chris and hallo list,

first I thought, I will send this message only to you, Chris [Borman], but then I thought it is worth to send it to the list as well.

Chris, thank you very much for the [personal] reply (missed your answer yesterday - sorry). As written in a previous note, I am really astonished how many people did improvements of this great instrument: the CC+, PSU, your CPS, the Enabler, I am sure I missed some. It is an exciting community. Just thinking back when I received my Chroma [in 2000; see 21010114] and Chris [Ryan] had the web page. It took me more than one year to fix it. I just thought I will fix it and sell it. But after a year of work, I heard its sound for the first time and never thought again to give it away. And I never regretted this decision. One day I will go for an Enabler finally because this makes the synth a very creative instrument with direct sound parameter access.

I do not know ANY other instrument where people put in so much energy to keep it up to date. There are some others worth to do it, but only few people are willing to spend their time to keep those instruments alive. So THANK YOU ALL FOR YOUR CONTRIBUTION TO THIS WONDERFUL INSTRUMENT.

Additionally there are only few user groups with this solid and friendly communication. This is worth to be mentioned again as well. Thank you to the best community in the world of synthesizers.



Most of us at one time have had the great honor of owning, playing, designing, supporting, repairing, etc. one of best synthesizers ever made! Think of it! And there may still be a few tricks up a few sleeves out there, right guys? :)

Chris Borman [21030194+]

Thank you Werner and Marias, you guys got that right! The CC+ guys are certainly the cream of the crop here replacing the logic, re-coding and enhancing the Chroma operating software. My contribution is a simple pile of variable resistors, but lots of fun to play nonetheless! Randel’s [21030467] Knob Box [Enabler] is of course very impressive! The PSU? Without that little utilitarian device, nothing else would matter over time. All the other contributions and of course Chris R [21030691] enabling us all worldwide to work together towards betterment of the instrument and ourselves.

I have thoroughly enjoyed working with the Chroma and all of you.

Luca Sasdelli [21010226]

I should add to your list the New EQ Board by Heinz [21010276]: even if not in production, Heinz put schematics and PCB layout available and his work is both a modern analog audio processor and a smart way to recover two CEM3360s, useful for DVB repairings. Such as a board would provide an easy way to replace the OAs with different ones, that could provide a sound that could match each own taste.

By building that new EQ Board, a Phones Amp would be easily added to the instrument.

Another interesting idea could be a brand new jack board, to better arrange all output wirings in a neat way.

Of course the most important remake would be the Dual Voice Board, but the problems in replacing the CEM3350 double VCF seems very hard to overcome (see Heinz' and Paul DeRocco' threads). Should this issue being solved, a new Channel Motherboard could be designed, with more robust connectors and maybe some improvements in the logic.

The possibilities are huge and exciting, to improve an incredibly sounding machine :)

Heinz Weierhorst [21010276]

Hi Luca, Hi all.

A new jack board is already done by me - i.e. two jack boards , one for audio the other for controlers as pedals and so on.

A new CMB was also finished two years ago. All connectors are gold plated and most of the digital stuff is replaced by two Lattice PLDs. Tom Wiltshires PIC noise is added and it's possible to have stereo on output 2 and 3. If stereo is unwanted the Chroma behaves as normal.

Another feature is an external audio input without killing noise, but that needs a little work on the CMBs. A resistor and a jumper is added.

The SSM2164 is no problem even production has ceased. There are enough around the world 'cause Behringer and others used them extensive in mixers and so on. On the other hand coolaudio is producing a clone. Something about new DVBs. A solution for new Filters and VCAs could be the SSM2164. They have build in expo convertors and need only minimal components for a filter. An excellent linear VCA was hooked up by Mike Irwine using one halve of the SSM2164.

For sale Chroma Expander upgraded

Rob Belcher [16330123]

Hello all,

Sadly it's time to sell my Chroma Expander. Unit has been fully upgraded at great expense. New switching power supply, replacing the old unreliable psu. CC+ cpu / midi board installed. Fully recapped throughout, all trimmers also replaced. New wood work.

Some spare CEM parts and user manual. Rare unit, i think there were about 250 Expander's made [see Instrument Registry]. Full working order and very good condition. Please email me if interested. For the record i have participated in discussions on the Chroma mailing list now and then for many years, i have also sold some chroma parts and cem chips to other members and have numerous refernces and feedback for those that would like it.

Item is located in the UK, local pickup or UPS shipping.

Rob Belcher.


Hopefully you have a Chroma keyboard still to keep. : )

Rob Belcher [16330123]

For sale restored Chroma Expander with CC+

Hi guys, I have had a fair bit of interest for my Expander but no sale yet. I have decided to reduce the asking price of the Expander to £4000. This price is firm, so please no offers. If any of you guys are looking for a fantastic condition restored Expander then this surely has to be the one! Ive posted some pictures of it in my advert for Gearslutz, so if you would like to see the condition and detailed description of restoration work have a look there: [url removed]

Chris Ryan [21030691]

Re: For sale restored Chroma Expander with CC+

Sold for £4000. This is Expander 16310012.

EES Chroma MIDI Interface for Sale

Chris Ryan [21030691]

Berry Goedemans has an EES MIDI interface for sale at Vemia: see item 9742. "Near mint" condition. Description: "The German company EES Technik für Musik produced this retrofit. It is an external interface with MIDI In and Out, selectable for Mono-Mode and 1-2-3 channel Multimode. It supports most of Chroma data including memory dumps for single sounds and all Chroma data (SysEx). More details: Lever 2: Pitch, Lever 1: Modulation, Volume: Control 7, Switch Channel Offset: MIDI Channel 1-8 or 9-16."


Polaris Atari Bank Loader (and other stuff)

Chris Ryan [21030691]

New on the site this month: some apps for Polaris owners who are Atari devotees (yes, perhaps a rarefied group), thanks to Albrecht Storz.

Chroma For Sale

Chris Ryan [21030691]

Noticed the site was getting a bunch of visits from and found a posting for a Chroma. Has the CC+, working condition, price €3250.


David Hobson [21030506]


Does anyone on this list have a soundDiver environment for Emagic SoundDiver? If yes, could you email me a copy?


Paul Hackett-Evans [21010094]

David, what do you mean by an environment, please? I have SoundDiver, but haven't used it for years since I sold my Chroma.

Chris Ryan [21030691]

See Mac OS X Editors & Librarians in the Patches section of the site.

David Hobson [21030506]


What I mean by environment is the library file that contains the data which sounddiver uses to set up for the instrument in question...I am using Mac OS 9.2.2 with Soundiver and I just need the set up for the Chroma. OS 9.2.2

Is that any more clear? Let me know and thanks.

Chris Ryan [21030691]

Yes, the library files for Chroma and Polaris are available at the site. However, note that SoundDiver itself required an XSKey, Emagic's copy protection dongle. I noticed that the downloads at Apple's linked from the site are gone; I'll remove the links, but again, they were of no use if you didn't have the dongle.

Paul Hackett-Evans [21010094]

I used my copy of SoundDiver on a PC, not a Mac. I didn't have a dongle. I seem to remember it only required to see the original cd-rom in the drive once every month for it to work.

David Hobson [21030506]


Well it looks like you cannot download it from your link or the legacy site (no such address anymore)...I am assuming that somebody out there owns what I Own, and needs it to work with OS 9.2. So if anybody out there has the file, let me know if you can help.

David Hobson [21030506]

Yes Paul, It requires you to have the disc and you need to insert it every month on macintosh OS 9.2

Chris Ryan [21030691]

Well it looks like you cannot download it from your link or the legacy site(no such address anymore).

Yes, that's what I indicated in my previous email. I will remove the link. But that link was to the application itself (and note that as this is the Mac OS X Editors & Librarians page, it was of course to the Mac version). But you had said you were looking for "the library file that contains the data which sounddiver uses to set up for the instrument in question." That file, Chroma.ADA, is indeed available from that page, and it's served from the site—I just confirmed by downloading it myself.

David Hobson [21030506]


I cannot seem to be able to use the link you are speaking of, and I think the "ADA" stands not f0or "environment" but what emagic called "adaptation". But if you feel like it maybe you could post the direct link for the ada file.

Thanks a million zillion,

Chris Ryan [21030691]

OK, trying to clear this up, I didn't know (or recall) that you weren't on Mac OS X. I'd advise upgrading; if your hardware can't support it, it isn't likely to work much longer--I hope you have backups. ;)

And I wasn't a SoundDiver user, so I don't know how its "environment" might have differed from that of Logic's. At any rate, you're right; ADA is an adaptation for a particular synthesizer. If you want a copy of that, it's available from the Mac OS X Editors & Librarians page.

David Hobson [21030506]

thanks chris

Chroma 21030379 on eBay

Chris Ryan [21030691]

Item #120893684602, USD$4,999.00. From the description: "The unit is 100% functional and in nice cosmetic shape as well. I just had it fully serviced and it works great. It will come exactly as shown below in the pics so take a peek [there are very good photos posted of the unit]. This piece has been tested and is guaranteed to be in proper working order or your money back!" This is Chroma 21030379, new to the registry.

Chroma 21030077 on eBay

Chris Ryan [21030691]

Item #270957645042, no reserve, ends April 18, 7 bids so far, current bid USD$305.00.

From the description: "Straight from an estate. It is in very good condition with normal scratches, nicks and wear but overall very nice. Keys are all in very good condition with no chips or damage. The wood end pieces show some scratches, nicks, wear and there is a chip at the back edge of the one on the bass end (see photo). It turns on and powers up. The LEDs blink as it boots up just as the manual says it should. The controls all seem to work. You can select any of the 50 program numbers and they are displayed on the digital read out. The volume slider is somewhat scratchy. When some of the keys are played I can only hear some very faint notes and sounds but every once in a while they get louder. It will also produce some swells of white noise sometimes when keys are played. Although I have no idea how to work it, it seems to need servicing. Since it does produce some sound I'm guessing it's nothing major. Since it needs servicing I'm selling it 'as is.'"

Has a Syntech interface installed, along with the original manual. Also a couple of laminates sheets listing the paramters that I don't think I've seen before.

This is Chroma 20130077, the only previous info of which was that it was being repaired five years ago.

Chris Ryan [21030691]

Sold for USD$2,601.00.

Chroma 21030921 for Sale on Gearslutz

Chris Ryan [21030691]

From Bart Kok: FS Rhodes Chroma met upgrade cpu++ [sic]: "With the upgrade cpu board [CC+]. Serviced in 2010 by Music House (Utrecht, The Netherlands). Prefer local pick up only. Everything works 100%. Located in the Netherlands. Ebay user name: Exwel. I want to sell the Chroma because i want to buy a Rob Hordijk modulair Synth. PRICE: 3250 euro."

This is Chroma 21030921.

Chris Ryan [21030691]

Sold for USD$ €2500.00.

Lars Johansson [21030632]

2500 USD ?

Chris Ryan [21030691]

USD = U.S. Dollars, as opposed to Canadian dollars (CAD), Australian dollars (AUD), and New Zealand dollars (NZD). All currencies are indicated in the Price History.

Lars Johansson [21030632]

Yes, of course.

I was just thinking it was a very low price.

In the Gearslutz ad it says 2650 Euros.

Chris Ryan [21030691]

Oh, you're right. I had just assumed—will change this. Thanks for spotting it.

A few of my membrane switches on my Chroma aren't working

Michael Dykehouse [21030757]

Hello everyone,have a quick question for you.

This hasn't really bothered my at all (this issue has been present since I purchased the unit) but just wondering if it might be a simple fix. My first main transpose (down 1 oct) switch, no link switch, and load one buttons aren't working. If I load a patch that was saved (not by me, a patch I downloaded) with the down 1 oct or no link buttons activated they will light up, I'm just not able to switch them on or off if I make a neighboring adjustment. The placement of the switches leads me to believe the problem is somehow related. Any clues? Thanks for your help!

Paul DeRocco [21030230]

Let's hope the problem isn't inside the switch panel, because I don't think anyone's got any replacements. (I've had a batch of Polaris panels made up, because they ALL fail eventually, but Chromas are generally reliable.)

You could try opening up the unit and examining the membrane switch tails. The switches in question are all driven by the first strobe line, which is on the leftmost pin of the leftmost tail (viewed from the front of the instrument when the panel is flipped up). It's almost certainly not an electrical problem on the board, because the same line that drives those three switches also drives some of the switches on the right panel, as well as the first digit in the parameter display.

I suggest carefully popping open the tail connector and examining the tail. The top part of the connector snaps open and hinges back, allowing the tail to be slid out with no friction. You can't pull the tail out without doing this because there are three hooks on the connector which engage holes in the tail.

It's possible that the problem is just some contamination that has settled on the tail, and that opening and closing the connector will solve the problem. You might try cleaning the end of the tail, but I suggest gentle friction with a pencil eraser rather than solvents, because I'm not sure what solvents won't attack the silver ink.

If there's any damage right at the end of the tail, it could be possible to trim the end of the tail, but then you'd have to cut new holes in the tail to match the hooks on the connector. It might actually be simpler to cut the hooks off the connector, and just rely on friction to hold the tail in, or use a piece of tape.

Whatever you do, just be very careful not to damage the tails, because as I said there are no replacement panels available.

John Leimseider [21030434++]

I have a couple of replacements for the Chroma and Expander… Not many, though.

Michael Dykehouse [21030757]

Ok thanks guys. I attached a photo-which one do I unhinge? Sorry and thanks again for your help:)


Michael Dykehouse [21030757]

A few of my switches...

Ugh uploaded the wrong photo... sorry. Anyways, I tried re-seating all the cables and using the eraser trick but no dice. John, is the replacement you have an entire membrane replacement? If so how much would you want for it and is it something I could easily replace? I may just live with the problem-it's not that big of a deal.Thanks for your help and I greatly appreciate it you guys:)

John Leimseider [21030434++]

Re: A few of my switches...

Please send me an Email off-group and we can figure this out.

Michael Dykehouse [21030757]

FIXED IT!!! Thanks so much Paul, the connection was just a little bit off. I love having this resource and really appreciate all of the help and feedback I have received. I don't feel guilty saying this (hehe) here but the Chroma mops the floor with ANY poly of the past or present. And with the support here and at Mr. Ryan's website I look forward to many of years with my baby:) All the best, Mike


Could this be explained further please perhaps with a photo in case it happens to one us down the road. Thanks you, M

Paul DeRocco [21030230]

FIXED IT!!! Thanks so much Paul, the connection was just a little bit off.

Glad you got it sorted out. With old electronics, connectors are always the first thing to suspect.

Slider caps wanted

Doug Terrebonne [21030114]

Hi, anyone have any spare slider caps? Need some for a Polaris...

David Gowin [21030611]

Second that, if any spare slider caps for a Polaris, more than happy to pay fair price. Thank you!

Paul DeRocco [21030230]

Technology Transplant has Polaris knobs for sale. I've bought two sets, and am satisfied with them. They work on the Polaris as well as the Chroma, except that the Chroma's levers are thicker, and require the original Chroma knobs. E-mail [address removed] and ask him about them.

Doug Terrebonne [21030114]

I'd rather not deal with someone who tries to blackmail fellow synth folks (see [removed link to deleted thread on forums] )... Was hoping someone on the list had some...

See thread Polaris sliders, May 2012

Question regarding saving patches after editing with an external (iPad) editor

Michael Dykehouse [21030757]

Hello again, another quick question. I have been using iChromaCC+ and my iPad to edit my Chroma lately and it works flawlessly. My only problem is saving my edits into the Chroma. If I start with a preset, alter it and then save it just saves as the original preset. Any help would be great and thanks again, Mike

Matrix [21030220]

I had the same problem. The following from David Clarke [see Saving CC+ MIDI Edits?, March 2012] worked for me:

This can be normal behaviour, depending on how you have the CC+ parameters set up.

Specifically - the CC+ allows you to chose whether the MIDI CC messages should affect the 'instrument' (e.g., settings currently live in the voice cards) or whether it should affect the 'program.'

The former allows you to manipulate the sound of a patch without changing it - as you might want to do in a played-back sequence from a sequencer. The latter allows edits to the current patch.

Editing on the Chroma itself always affects the main program.

Check the setting of the "Select MIDI Continuous Controller Mode" from the CC+ configuration menu:

[Set Split][36] + P24

If "Inst" is selected, the Continuous Controller data will only affect the 'instrument', and not affect the program. (i.e., the changes are gone when the program is reselected, the Chroma is turned off, etc.) If "Prog" is selected, then any Continuous Controller data will change the values for Program 0 - and hence you'll be able to save it with the program (if you like).

(This selection was added as of firmware version 209)

Dave Blees [21030552]

Mike - Did you check the state of the LOCK/UNLOCK switch?