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ChromaTalk Archives: Feburary 2013

Ring mod patch and wave shape/width

David Hobson [21030506] · Fri, 1 Feb 2013 17:29:59 -0500

Hello,

I was wondering if anybody on the list may know why the wave width settings need to be at or near 32 to discern an audible ring modulation.

Do the width parameters serve double duty as volume for the ring mod? What exactly is going on in the Chroma when using the ring mod?

Thanks,

David Hobson 21030506

Heinz Weierhorst [21010276] · Sat, 2 Feb 2013 13:47:53 +0100

Hi David.

Because the Chromas ring mod is an digital one, exor gate in this case, it's only a real ring mod when both inputs are 50% squares.

David Hobson [21030506] · Sun, 3 Feb 2013 00:24:32 -0500

Heinz,

Thank you for your reply.

It's alive but not tuning

Daniel Benoit [21030109] · Fri, 01 Feb 2013 22:39:20 -0500

Hi

A few year ago my Chroma when down...All voiceboards wouldn't tune. After spending a lot of days trying to make it work, (changing most of the logic and analog ic's) on the I/O board and motherboard, It decided to put it aside.

Yesteday a spent a few hours going thru all the tuning related circuits and changed the last IC's that were on the tuning path. it almost worked...

Now my chroma will sometime go thru the tuning sequence, disable a few voiceboards, and keep the others active. (in a almost kind of random way...)

When played, the active voiceboards are way out of tune... If I do repeated "setsplit+50"s, the active voiceboards endup disabled

This Chroma has the CC+ and PSU upgrade installed, all DC voltage are clean and exactly in the "ok" range (12.07V/-12.08V/digital =5.01V/ analog = 5.05V)

All Adjustements on I/O board and voiceboards are OK (DA offset = 0.000V) VR1/2on voiceboards adjusted to 50% duty cylce of waveform.

When I look with the scope, the Zero crossing signal is clean and seems to work

What could I be missing out?

Any help and advice would be appriaciated

Daniel Benoit

Chroma in Montreal

Technician Larry [21030198] · Fri, 1 Feb 2013 20:49:15 -0800

Autotune problems possibly caused by some weak link in the signal path perhaps(?). I recently serviced a Memorymoog that always failed one particular voice. The voice sounded fine, but the final VCA, a CEM3360, had noticeably less output signal voltage peak to peak than the other voices. While this was obvious when looking at it with the scope, audibly it was not at all obvious. In fact, I couldn't hear the difference, yet moving this socketed IC from voice to voice proved that a couple of db drop in signal level was most certainly the problem. I remember another autotune issue on some other synth years back with symptoms similar to what you describe. The fix was replacing a multiplex IC on the CPU board that was passing weak signals. I'm not familiar with the Chroma autotune configuration, but I thought perhaps these observations might be relevant.

Some Chroma Troubles with CC+

Go to first message in thread, January 2013

John Leimseider [21030434++] · Tue, 5 Feb 2013 09:40:14 -0700

On Jan 13, 2013, at 9:26 AM, matrix wrote:

Which template are you using? There are two, one for The Missing Link and one for Core Midi. The one for The Missing Link is wireless but will not work with other Midi adapters.

Have you tried the core MIDI version? Did you write one of them? I'd really like to get this going... Thanks!

Leon van der Sangen [21010301] · Tue, 5 Feb 2013 17:55:46 +0100

Hi,

The Irig should work with the core midi. The editor to use is found at iPad Editors: TouchOSC iPad Template Modifications.

Marais · Tue, 5 Feb 2013 12:21:27 -0500

I use an Alesis I/O dock (make sure your iPad iOS is updated), works fine.

John Leimseider [21030434++] · Tue, 5 Feb 2013 10:14:11 -0700

Do I need the camera connection kit also, or just the Irig? Sorry for the ignorant questions... I fix synths, I don't know all that much about computers... Thanks for your help!

Leon van der Sangen [21010301] · Tue, 5 Feb 2013 18:21:00 +0100

If it's the irig-midi you only need the irig and the irig midicable

Parameter Chart Version 2.1

Chris Ryan [21030691] · Tue, 5 Feb 2013 22:38:03 -0800

I've made some changes and improvements to the parameter chart. Version 2.1 additions and corrections:

  • Hyperlinks from the PDF to the appropriate content on the web site for:
  • Fixed the diagram for Patch [1] value 4: added FM indicator between Amplifier B and Filter A.
  • Fixed the diagram for Patch [1] values 5 through 7: the connector line between the Osc A to Filter A, and Amp B to Filter B, has been adjusted to correspond to that in the Programming Manual (non-directional).
  • There are now three entries for Set Split 20: stock; Syntech; and CC+ – all linked to the corresponding content on the site.
  • Set Split 25 is now labelled "Execute Subroutine," as in the manual, rather than "Branch Subroutine" (it's not labelled at all on the original chart).
  • There are now separate entries for Set Split parameters P2 and P3 for Syntech and CC+.
  • Various other fixes and minor adjustments.
  • A few related fixes to Programming Manual: Panel Parameter Descriptions.

Note that I am no longer maintaining the "original parameter chart" (v1.x) PDF, so there will be some errors and omissions in it.

Thanks to Eric Mattei [21030443+] for extensive help with this; also David Clarke [21030085++].

On another topic, there have been some issues with the mailing list in the last couple of weeks. I'm working on it and had to reinstate some of you who were unsubscribed automatically due to some overzealous spam protection programs (it's entirely possible that the same thing will happen again). If you missed some messages, please check the January archives; in particular, Eric's post Patch [1], Value = 9 Series Filter doc on which we'd like some feedback.

David Hobson [21030506] · Tue, 12 Feb 2013 23:39:45 -0500

Parameter Chart

Thank you Chris for putting together the new and revamped Parameter Chart. Thanks for the effort.

Chris Ryan [21030691] · Tue, 12 Feb 2013 20:49:42 -0800

You're most welcome. I hope some may find it useful.

AT unresponsive with CPS kit

Philippe [21010227] · Thu, 7 Feb 2013 19:49:11 +0100

Hi list,

I have just added the CPSkit to my Chroma but the Chroma doesn't react at all to the pressure applied to the kit. My CPS kit installation seems to be fine as when I install the damper bar+CPSkit into another Chroma the AT works perfectly. So it seems the problem is into the Chroma itself.

I have dismantled the big board where J22 is soldered to verify that it was well-soldered with continuity tests and it seems all is fine. I even have dismantled the plastic connector of J22 and cleaned inside with alcohol but still nothing is happening. Would you suspect anything obvious that could be dead in the way from J22 to the CC+ that would cause AT to be unresponsive ?

(CC+ firmware is 215, I did Set Split 35 and applied maximum mod depth to pitch)

David Clarke [21030085++] · Thu, 7 Feb 2013 22:18:51 -0400

... So it seems the problem is into the Chroma itself. ... I have dismantled the big board where J22 is soldered to verify that it was well-soldered with continuity tests and it seems all is fine. I even have dismantled the plastic connector of J22 and cleaned inside with alcohol but still nothing is happening...

As a minimum I'd likely recommend looking at the signals on J22 with a 'scope.

You'd want to see if you're getting the strobes for the keys. Since you have another chroma that works with the interface, you could compare what you see on one vs. the other.

Beyond the strobes, I'd check to confirm that the supply voltages are present on the J22 connector - and then to monitor the PRESS analog output from the sensor. If you can see that signal pick up the pressure assertions from keys, then I'd go to the PRESS input to the ADC to confirm it makes it that far.

Philippe [21010227] · Mon, 11 Feb 2013 01:13:00 +0100

Hi David,

Thanks for your advices.

Since I have no scope I flipped the control panel up, unplugged the flat ribbon from J22 and measured voltages of J22 with a Multimeter. I got from left to right :

Chroma CPS working :

  • upper row : 0.03 - 0.70 - 0.03 - 5.01 - 0.03 - 5.05 - 12.01
  • lower row: -11.98 - 0 - 0.03 - 5.01 - 0.03 - 0.69 - 5.01

Chroma CPS not working:

  • upper row : 0.03 - 0.70 - 0 - 0 - 0 - 5.06 - 12.06
  • lower row: -12.11 - 0 - 0 - 0 - 0 - 0,71 - 5.03

the 4th hole of each row is missing its 5V. Does that tell you something about what might be going wrong ?

David Clarke [21030085++] · Sun, 10 Feb 2013 21:39:39 -0400

Since I have no scope I flipped the control panel up, unplugged the flat ribbon from J22 and measured voltages of J22 with a Multimeter. I got from left to right : ...

If you were looking at the connector as it would appear with the panel flipped up, then it would seem that the 'upper row' and 'lower row' values would correspond to:

Upper Row:

  • J22-7 = Digital Ground
  • J22-6 = Pressure Output from Sensor (also J22-13)
  • J22-5 = KS1
  • J22-4 = KS3
  • J22-3 = KS5
  • J22-2 = Analog 5V
  • J22-1 = Analog +12V

LowerRow:

  • J22-8 = Analog -12V
  • J22-9 = Analog Ground
  • J22-10 = KS0
  • J22-11 = KS2
  • J22-12 = KS4
  • J22-13 = Pressure Output from Sensor (also J22-6)
  • J22-14 = Digital 5V

Based on your measurements, both the working and not working configurations appear to have nominally proper 'voltages' (e.g., ground, 5V, +/-12V, etc.). The difference between the two cases are the "KS" signals.

You'll see that the "KS" signals come from Z30 on the I/O board, as seen on the middle, left-hand side of I/O Board Schematic 1.

When the WR_PRSS strobe becomes active, the values on the "D" inputs will be latched to appear on the "Q" outputs of that chip.

I believe the pressure will only be read when there is a key pressed/held for which the pressure value needs to be read. That means that you should generally only expect to see WR_PRSS become active when keys/notes are active.

As noted in Pressure Sensor & Interface: Technical.

The values on the KS0 - KS5 signals will uniquely select one of 64 keys for a pressure measurement.

Generally speaking, you need a scope to determine if these are doing what they should nor not - but if you only have a multimeter available, you may be able to get a sense of operation if you hold the same, single key on both the 'good' and 'bad' keyboards, and re-measure the KS signals and compare.

If you do see a difference, then focus would go to Z30 (which is immediately to the left of J22). Again - without a 'scope it would now be difficult to know if the issue is actually with Z30 (unless you can see physical damage on that chip/detect a lack of power/group to the chip) or something else (such as the WR_PRSS strobe signal).

Philippe [21010227] · Mon, 11 Feb 2013 13:00:05 +0100

Well actually Z30 is simply absent on my board ! I guess the next obvious step is to find the corresponding chip. Does Z30 have another job beyond transmitting pressure ?

David Clarke [21030085++] · Mon, 11 Feb 2013 08:38:05 -0400

Z30 is used to pass on the 'key' information to the pressure sensor (so the pressure sensor will know what key sensor to provide pressure data for). It is only used for this purpose and does not impact other functionality in the keyboard.

Z30 is essential for pressure sensor operation.

Paul DeRocco [21030230] · Mon, 11 Feb 2013 08:32:23 -0800

From: Phil a

Well actually Z30 is simply absent on my board !

I guess the next obvious step is to find the corresponding chip. Does Z30 have another job beyond transmitting pressure ?

Ahah. I suspect that the production department decided that, since they had never got around to manufacturing any sensors for sale, they could save the cost of one IC. Fortunately, it's a cheap and readily available IC. Any of these will work:

Since its purpose is to latch the key number and deliver it to the board, this would have left key 0 permanently selected. Didn't you notice that the bottom key worked perfectly? ;-)

Philippe [21010227] · Mon, 11 Feb 2013 18:23:24 +0100

Thanks for the links. No, I didn't notice, I probably didn't play that note in particular since none of the first keys I played worked.

Robb Witt · Mon, 11 Feb 2013 17:33:57 -0500

I love this board. Where else could you get insight like this?

Philippe [21010227] · Mon, 11 Feb 2013 23:43:12 +0100

+1 !

Doug Wellington [21030300] · Mon, 11 Feb 2013 15:47:40 -0700

I love this board. Where else could you get insight like this?

Yeah, this is cool.

A while back, a couple of us were trying to get something similar going about the Ensoniq PARIS system. We got some new effects development going and one of the guys even made a VST version of the EQ. Of course, once all the young punks graduated from college, they were gone.

Makes me appreciate this group all the more...

Paul DeRocco [21030230] · Mon, 11 Feb 2013 15:17:42 -0800

Yeah, here you get old farts like me instead of young punks.

Doug Wellington [21030300] · Mon, 11 Feb 2013 16:33:32 -0700

Heehee! Well, relative to some, I count as an old fart, having been born in the 50's...

Chroma with CC+ For Sale from RL Music

Chris Ryan [21030691] · Mon, 11 Feb 2013 23:24:30 -0800

"This superb example was brought in from the USA and we have subjected it to an extensive restorative overhaul, both cosmetically and operationally ... brand new 5 volt PSU" and the "amazing" CC+. £5690. See the listing on RL Music's site.

I asked Richard about the serial number and we're pretty sure it's 21030379, which was sold last year (and had similarly great photos, pre-restoration).

SN21030379a

SN21030379b

Syntech/Chroma Cult/KMX MIDI interface on eBay

Chris Ryan [21030691] · Mon, 18 Feb 2013 12:51:13 -0800

Item #300863489089, two available at USD$250.00, ends March 19. "New in box. Purchased from manufacturer!" Rest of description copied directly from the manual at the site.

eBay300863489089

Ken Ypparila [21030229] · Mon, 18 Feb 2013 13:10:52 -0800

I think he bought my last two several months ago.

Eric W. Mattei [21030443+] · Mon, 18 Feb 2013 13:27:53 -0800

If I'm not mistaken, that's one heck of a mark up. But if they're the last fresh ones in the world, I guess it's understandable.

Ken Ypparila [21030229] · Mon, 18 Feb 2013 14:54:25 -0800

500%

Rhodes Chroma

David [21030184] · Sat, 23 Feb 2013 23:06:10 -0500

I have a Chroma that is in excellent physical condition. It appears to have a new power source, the MIDI upgrade and the CPU Plus (CC+) upgrade. It powers up and responds to commands but does not produce sound. I followed the instructions to check the mother board and the EQ board by re- directing the output signal to socket numbers 2 or 3 but still got no sound. Since I am not a music equipment guy, maybe I am doing something incorrectly in an attempt to get this synth to play. Any suggestions would be greatly appreciated.

Thanks…David

David Clarke [21030085++] · Sun, 24 Feb 2013 00:40:33 -0400

I have a Chroma that is in excellent physical condition...It powers up and responds to commands but does not produce sound...

David - do you know the history of this keyboard? Specifically - was it originally believed to be OK/making sound, or is this a unit that is known to have issues?

Assuming it was believe to been OK, there is a possibility that it is just a simple matter of the keyboard not actually being configured to locally produce sound (e.g., set to 'local off' mode).

As you noted that there was a CC+ installted, some quick/easy things to check:

Enter programming mode by selecting [SET SPLIT][36].

  • Press P17 and confirm that it is set to "On" (Local Control)
  • Press P22 and confirm that it is set to "Chro" (Chroma, vs. Expander)

Exit programming mode (e.g., enter [SET SPLIT][36] again).

Select [SET SPLIT][39] to create a scratch patch.

Select [SET SPLIT][37] to enter voice-watch mode. When you press keys, you should see elements of the small LED display light up. If you do not, there is a problem with the reading of the keyboard data into the Chroma. If you do and now also hear sounds - then there was a problem with one of the settings above (e.g., perhaps local control turned off, or the unit somehow set to act like an Expander vs. a Chroma).

If you see the LED displays, but don't hear any output, then we'd be looking for something amiss on the volume side. If a Volume pedal is installed, it should be shifted to the other state. It would be worth-while also assessing if there is audio out either the XLR or 1/4" jacks.

Let us know how you make out/what you see during your tests.

David [21030184] · Sun, 24 Feb 2013 00:02:11 -0500

David,

I inherited this as part of an estate. Knowing who the previous owner was I would bet that the unit was in working order but positive. I know it was part of a studio and I believe the fairly talented previous owner did some music mixing and other technical things associated with the music world so very possible it is not set to "local control". I will run some of the tests you suggested tomorrow and let you know how I make out.

Really appreciate the help.

David [21030184] · Sun, 24 Feb 2013 09:06:40 -0500

David,

One other stupid question. Do I need an amp plugged in for the unit to produce sound?

Marais · Sun, 24 Feb 2013 09:50:43 -0500

just some other tips,

make sure you're using the 1/4" mono output, this needs to go to an amp w/speaker, stereo, powered computer speakers for ie.to hear anything.

volume slider up, and control volume pedal (if connected) up

David [21030184] · Sun, 24 Feb 2013 09:52:08 -0500

Thanks...let's see what happens

David [21030184] · Sun, 24 Feb 2013 13:55:28 -0500

Dave, Not sure if I did everything correctly or not but still no sound. Any chance we could talk on the phone? Tks....David

David Clarke [21030085++] · Mon, 25 Feb 2013 16:02:40 -0400

David - a call will likely be logistically difficult for the next while.

That said - if you can provide some indications back to the group of what was/wasn't seen then others can also help.

To recap, there are no speakers intended to be built in to the Chroma - and so yes, you do require an external speaker/AMP connection. The location of connection is also also potentially important.

With reference to this drawing:

backpanel

(as visible from Performance Manual: Hookup)

you'd normally connect a mono 1/4" jack to one of the 'Mono Out' jacks.

When you pressed the [Set Split] button, followed by pressing the "37" button from the right hand side of the control panel [to select 'voice watch mode' - what (if anything) did you see in the small LED display on the Chroma when you pressed keys?

Did you see anything show up, or did it remain completely blank (regardless of whether keys were pressed or not)?

Nicholas Vining [21030777] · Mon, 25 Feb 2013 16:04:08 -0800

Hi David (non-Clarke David):

Can you let us know what the serial # of the Chroma is? It would be interesting (and possibly helpful) for us to know if it is already in the registry; the previous owners may have left Clues.

David [21030184] · Mon, 25 Feb 2013 19:45:54 -0500

Nick,

I can't find a serial number anywhere...I will look again. I do know the previous owners name. Can we look him up that way?

Nicholas Vining [21030777] · Mon, 25 Feb 2013 16:49:54 -0800

It should be on the back of the Chroma, by the power switch, on a little metal screwed-in inset thingy with "S/N" written on it. Is that plaque not there?

David [21030184] · Mon, 25 Feb 2013 20:01:48 -0500

Nick, Plate is not there and couldn't find it inside where it is supposed to be...seems odd. I guess we can't look for the previous owner by name. Also, David C. I did run those tests you asked and will try to give you the feedback via email shortly. When I went into programing mode and hit P17 it said OFF. Is it a toggle to turn it back on to local?

Nicholas Vining [21030777] · Mon, 25 Feb 2013 17:07:19 -0800

You can try the Chroma registry:

to see if you can find the person in question, but you'll just have to search each page by hand. It puzzles me that somebody would have a CC+ and *not* be in the registry, so your chances are pretty good.

David Clarke [21030085++] · Mon, 25 Feb 2013 21:22:00 -0400

... David C. I did run those tests you asked and will try to give you the feedback via email shortly. When I went into programing mode and hit P17 it said OFF. Is it a toggle to turn it back on to local?

If it says 'off', you'll want to change it to say 'on.'

To change the value, use the Parameter Control Slider to the left of the big 2 digit LED display on the panel.

As you move the slider up, you should see the value change from 'off' to 'on'.

David [21030184] · Mon, 25 Feb 2013 20:47:09 -0500

Nick, Nice going...found a post from the original owner. Would the serial # be above his name or below? I'm assuming above. Apparently it was working fine in Jan. 09 except for one voice card. He may have fixed that buy the time I got it. I'm going to see if I can get the local on...Thanks guys...

Here is his post: [See the entry for 21030184]

David [21030184] · Mon, 25 Feb 2013 21:19:11 -0500

If it says 'off', you'll want to change it to say 'on.'

To change the value, use the Parameter Control Slider to the left of the big 2 digit LED display on the panel.

As you move the slider up, you should see the value change from 'off' to 'on'.

David, You have made my day, my month and my year. You are the man. The Chroma is producing sound!!! FINALLY I know what it sounds like. Had it listed for sale and spoke to dozens of interested people and not one of them had a clue what to do to make it work. Maybe they did and were using that to try and negotiate a price well below its value. I really do owe you one. Thank you so much!!

I went through the keys and a couple of them when pressed the sound continued as though they stuck. Didn't know what to do at that point to get the sound to stop so I shut it down for about 10 seconds then back on and it stopped. Does it need to be cleaned?

David Clarke [21030085++] · Mon, 25 Feb 2013 22:34:34 -0400

... The Chroma is producing sound!!!

The 'Local Off' setting makes sense given your earlier posting where the previous owner had noted that they used it as their 'master keyboard'.

Of course, if you were just looking to use the Chroma standalone (as you were), you certainly want Local Control 'On', so they keys will cause the Keyboard to make sound locally.

Glad to hear that things now seem to be generally operational.

I went through the keys and a couple of them when pressed the sound continued as though they stuck. Didn't know what to do at that point to get the sound to stop so I shut it down for about 10 seconds then back on and it stopped. Does it need to be cleaned?

They key contacts could just be dirty, or they may be out of adjustment.

Take a peek at Chroma Keyboard Repairs (January 2012)

(There will be other discussions in the archives too which can be searched from the 'site search' box on the main page.)

David [21030184] · Tue, 26 Feb 2013 21:09:15 -0500

David, Can I turn it on with the cover off or does the ground wire need to be connected? Also is there a way to stop the sound produced by the stuck key without turning it off completely? Also is the serial # above the persons names in the posting or below the posting? Want to make sure to make a note of the correct number.... Thanks again

Paul DeRocco [21030230] · Tue, 26 Feb 2013 18:18:23 -0800

From: DLE

David, Can I turn it on with the cover off or does the ground wire need to be connected?

Just make sure the loose ground wire doesn't short to anything else.

Also is there a way to stop the sound produced by the stuck key without turning it off completely?

Stuck notes are almost always dirty contacts, but they can also be bent contacts. If you examine the switch contacts, you should be able to see if anything looks crooked. If not, you can clean them by cutting a strip of paper, dousing it with alcohol, pressing the key, inserting the wet paper between the moving contact and lower contact, releasing the key, and then wiggling the paper back and forth. The paper has just enough abrasion to take off most junk. You can clean the other side by sliding the paper between the moving contact and the upper contact with the key released, then pressing the key, and wiggling the paper.

Also is the serial # above the persons names in the posting or below the posting? Want to make sure to make a note of the correct number.... Thanks again

The number is above the name.

David [21030184] · Tue, 26 Feb 2013 21:23:45 -0500

Thanks Paul...

David Clarke [21030085++] · Tue, 26 Feb 2013 22:27:17 -0400

Just make sure the loose ground wire doesn't short to anything else.

David - following up to Paul's reply, it is also possible to have the cover off AND to leave the ground wire connected. You can just sit the cover behind the Chroma, leaving the rear-panel ground wire attached.

The presence/absence of the ground going to the rear panel won't in and of itself affect operation (e.g., you're OK to leave it on - or to disconnect it while the lid is off - but as noted by Paul, if disconnected, watch out where it ends up gonig).

David [21030184] · Tue, 26 Feb 2013 21:40:24 -0500

Thanks David..

Using the chroma on its side?

Joe Porter [21030058] · Sun, 24 Feb 2013 17:16:18 +0000

Hi,

Has anyone on the mailing list used their chroma on its side without any problems? I'm moving stuff about in my studio and since I only use the chroma now with MIDI, I was thinking of putting it on/against a wall so it takes up less studio space. Probably keys side down, back (where connectors are) up. Am I going to have problems with voice cards coming loose etc. or will it continue to work fine in this position? Any advice?

Thanks,
Joe

Chris Ryan [21030691] · Sun, 24 Feb 2013 09:18:05 -0800

I used my Chroma via MIDI on its side for several years and never had a problem.

Joe Porter [21030058] · Sun, 24 Feb 2013 17:36:05 +0000

Thanks Chris. Was that with the left or right side facing down or with the side where the keys are facing down?

Chris Ryan [21030691] · Sun, 24 Feb 2013 09:41:19 -0800

Left or right—not sure which.

New to midi and bcr2000

David Hobson [21030506] · Mon, 25 Feb 2013 13:15:41 -0500

Hello,

I have read through the entire article on the bcr2000 and its use with the Chroma and I believe I set everything up correctly, but nothing changes.

I installed the .syx to the bcr2000 and plugged it into the midi interface (syntech) and noting changes when i rotate the cutoff dial.

All I want the BCR2000 for is programming the Chroma WITHOUT connecting it to my computer, just by itself. I don't know hardly anything about this still after reading the article except how to set up the CC+.

I know i am doing something wrong, but I for the life of me cannot figure out what.

Seeing all I want to do is directly connect the bcr2000 to my midi interface could somebody provide me with a simple setup for both the bcr2000 and the CC+?

Currently, the bcr2000 is setup as S-3

The CC+ is set up like it says on the site:

Configuring the Chroma

On the Chroma/Expander perform the following:

  • [Set Split 36]
  • Select [P6] - Ensure set to “On”
  • Select [P18] - Select “CUSt”
  • Select [P20] - Move “Parameter Control” slider
  • Select [P24] - Select “Prog”
  • [Set Split 36]
  • Can anyone help me?

Thank you,

David Hobson

David Clarke [21030085++] · Mon, 25 Feb 2013 15:56:29 -0400

I have read through the entire article on the bcr2000 and its use with the Chroma and I believe I set everything up correctly, but nothing changes...

David - with reference to the 'troubleshooting' section from BCR2000 Set Up, what do you see/what don't you see?

For instance, assuming that the BCR2000 is set for program "1", do you see the MIDI Out LED on the BCR 2000 illuminate? (If not, attention would be in the programming of the BCR2000).

If the BCR2000 MIDI Out LED illuminates (in response to turning a knob on the BCR2000), do you see the MIDI in LED on the MIDI CC+ (or in the Chroma's LED display) flash? IF you see the BCR2000 LED flash but not the one on the Chroma, is the Chroma's base MIDI channel set to correspond to the channel that the BCR2000 is transmitting on?

David Hobson [21030506] · Mon, 25 Feb 2013 15:51:29 -0500

Hello David,

And thanks for your reply.

I got it to a point where the midi lights on the bcr are lit when i play the keyboard. The lights also light up when i depress the keyboard...The .syx is loaded and it is just midi in and midi out to the chroma from the bcr. I This is what happens...I get a dislay in the chroma that says "DP error" when i change from edit a to edit b. I do not know what that means. I will try changing the midi channel

Any further helps would be appreciated,

David

David Clarke [21030085++] · Mon, 25 Feb 2013 17:07:31 -0400

I got it to a point where the midi lights on the bcr are lit when i play the keyboard... ... I get a dislay in the chroma that says "DP error" when i change from edit a to edit b.

David - the "DP error" message is something I would normally expect to see with the Syntech MIDI interface (vs. the CC+). It generally indicates that the unit has received a SYSEX message that it doesn't understand.

While I'm aware of you having the CC+, I do not recall you getting the MIDI cable set for it. Did you perhaps build a set yourself - or might you be using MIDI via the Syntech/KMX MIDI interface? E.g., in terms of the physical attachment of the MIDI cables to the Chroma, where do the cables go? Do they go to a box that looks like the Syntech, connectors directly attached to the back of the Chroma or other?

David Hobson [21030506] · Mon, 25 Feb 2013 18:45:17 -0500

Hello David,

I am using the syntech interface (the rectangular black box that plugs in the scsi port) I have the in from the bcr2000 going from the the out of syntech...and i have the out from the bcr going to the in on syntech. and the syntech is plugged into the back of the Chroma And I did not buy the midi cable, I am hoping that this can be figured out:)

Regards, David

David Hobson [21030506] · Mon, 25 Feb 2013 19:44:08 -0500

Hello,

I hope this goes to the rest of the users,

I have a bcr2000 hooked up to my chroma vis a syntech interface. I dowloaded the .syx file to program th BCR2000, but then I unplugged the coputer and dedicated the in and out to the chroma directly.

The midi lights com on on the BCR2000 when the keyboard is played and the lights come on when i turn a knob on the bcr2000 but the Chroma ignores it, it seems.

I just bought this bcr2000 new and I would like to get working on some patches...would someone on the Chroma mailing list help me out?

I would appreciate it,

Thanks,

David Hobson

David Clarke [21030085++] · Mon, 25 Feb 2013 20:49:10 -0400

... I am using the syntech interface... I have the in from the bcr2000 going from the the out of syntech...

David - this is sort of a good news, not-so-good news situation.

Based on the obversations you've shared earlier, the good news is:

  • the BCR2000 is likely programmed correctly with the .syx files;
  • the connections between the BCR2000 and the Chroma are OK;
  • the BCR2000 is sending data; and,
  • the Chroma is receiving MIDI data.

The not-so-good news is:

  • the Syntech interface does not allow you to control all of the Chroma's parameters via MIDI continuous controllers
  • the BCR2000 programs that are on the Chroma site are specifically intended for the CC+ MIDI interface that allows you to full access to all of the parameters, and allows the BCR2000's parameters to be updated based on a SYSEX request from the BCR2000.

The "Why the CC+?" paragraph in the BCR2000 setup page touches on this.

In this paragraph, the reference to the CC+ isn't just to the CPU board, but is specifically a reference to using the MIDI interface provided by the CC+.

There would be nothing to prevent you from successfully using the BCR2000 with the Chroma and the Syntech interface - but:

  1. You'd not have access to all of the parameters;
  2. You'd not have access to some of the other 'talkback' features offered by the CC+ MIDI interface; and,
  3. You couldn't use the .syx files for the BCR2000 currently on the Chroma site for the BCR2000; rather, you would need to modify the BCR2000 controller map to match what the Syntech interface expects.

David Hobson [21030506] · Mon, 25 Feb 2013 20:04:20 -0500

Well,

Thats not the best news I have heard, but I guess could buy a cc+ midi cable because I need it and I want it. You have answered my queston,

Thanks for that mate!

David Hobson [21030506] · Mon, 25 Feb 2013 20:11:51 -0500

Another question and i will desist, Is the cc+ midi cable still availabe? Could you send me the link if they are available? Thank you, David hobson

David Clarke [21030085++] · Mon, 25 Feb 2013 22:28:50 -0400

Thats not the best news I have heard, but I guess could buy a cc+ midi cable because I need it and I want it... Is the cc+ midi cable still availabe? Could you send me the link if they are available?

David - some general options, starting from the fastest/cheapest:

Use the Syntech interface with the BCR2000

You already have all the hardware, and so this is a $0 cost approach. While you may not have control over every parameter, the Syntech interface is a nice, solid, reliable interface that will still offer a good amount of usable control.

You can use the features of the BCR2000 to 'learn' parameters, or use the free B-Control Edit/BC Manager software (referenced on the BCR2000 page) to graphically set parameters. With some changes to the BCR2000 setup, you could be up and running with the combination of hardware you already have in just a few hours.

Build your own CC+ Cable

If you're not looking to eventually add on the alphanumeric display (http://www.rhodeschroma.com/?id=cpuplusalphadisplay) and you don't need a pretty box - you can build your own cable with just:

  • 1 6-pin connector
  • 5+ feet of cable
  • 2 5-pin circular DIN (MIDI) connectors

You can use the 'MIDI' connections shown here: Wiring Diagrams for Internal and External Cables

For $10 - $20 worth of parts, you could have a functional interface in a couple of days (the time to get the connectors, if not already on hand).

Order a CC+ Cable

While these are most commonly purchased (and tested) as part of a CC+ order, they could be purchased separately.

The cable set consists of the 'Internal' and 'External' cables shown here:

(While the picture on the site shows a plain silver covered face for the MIDI box - all but the very first North Amercian-built units have actually a black face with an orange legend, as shown in the attached).

Per the information here: How Can I Get a CC+?

The CC+ MIDI Interconnection kit/cable is $70 USD.

The next planned build/test of units will likely occur at the start of April (e.g., read to mean - none of these are currently on-hand, if one was desired, April would likely be the soonest it would be available).

Best regards,

David Clarke

David Hobson [21030506] · Tue, 26 Feb 2013 00:44:24 -0500

Templates for BCR2000

Hello group!

Is there anybody out there who uses a syntech midi interface with their BCR2000 who would not mind sharing your setup with me? It would help alot,

Thanks,

David

Seattle - Polaris and other ARP classics for sale

Brian McCully [21030361] · Tue, 26 Feb 2013 17:50:23 -0800

I sometimes stop by the Trading Musician in Seattle, and today there was a motherlode of old keyboards there. There's a Chroma Polaris (with possibly 1 voice out - I didn't try it, but it was under $200), a Quadra in great shape, a 2600 in really nice shape (~$4900), an Odyssey (I think...) and also there, was a Chroma Expander (#0120) and a Chroma (with the halloween front panel, but no visible serial number, and smells like it toasted something inside big time), but they are now gone, as I couldn't help myself. My wife could only say "well I guess you've got a project on your hands". I never ever thought that I would own an Expander...

I've got 48 hours to get cash back, but I think for now I've just got a lot more Chroma in house. I will definitely be asking some questions of the list - maybe post some pix too. There is MIDI on both of them - three MIDI DINs close to one another, which I don't recognize. Anyway I just wanted to post this to let the list know that the Polaris (etc) is/was available. cheers, -Brian

David Clarke [21030085++] · Tue, 26 Feb 2013 22:22:10 -0400

Chroma and Expander

... there, was a Chroma Expander (#0120) and a Chroma (with the halloween front panel, but no visible serial number, and smells like it toasted something inside big time), but they are now gone, as I couldn't help myself...

Congratulations on your purchases!

One of the things I've always liked about the Chroma/Chroma Expander is that most of the things inside can still be fixed with items that are available, making them quite servicable in the long term.

As long as all the big, mechanical pieces are there (and someone hasn't pulled all the CEM chips) - you generally should be fine.

... My wife could only say "well I guess you've got a project on your hands".

I know that the wives of a lot of my gear-buying friends would not necessarily be so understanding :->

The 0120 Expander seems to have sold on Ebay back in 2011 for 6,800. Here's hoping you were able to get a significantly better deal.

It would be good to be able to see if the Halloween Chroma has a serial number inside and to get some additional information for the registry.

... There is MIDI on both of them - three MIDI DINs close to one another, which I don't recognize.

Perhaps the Kenton kit?

Paul DeRocco [21030230] · Tue, 26 Feb 2013 18:20:56 -0800

Lucky you. If you find the Chroma beyond repair, and want to dump it, let me know. I'm always on the lookout for gutless Chromas to put my Digital Chroma stuff inside.

Nicholas Vining [21030777] · Tue, 26 Feb 2013 18:22:29 -0800

Re: Chroma and Expander

Trading Musician's website has the Chroma Expander listed for $999.00. So yes, he got a good deal indeed. :-)

That said... how in the world did it end up over there?

Brian McCully [21030361] · Tue, 26 Feb 2013 19:44:58 -0800

Re: Chroma and Expander

Thanks, David. The first thing I need to do is pry them open to look for the darn batteries (which is why your brainboard upgrade rocks!) and then swap them out immediately - hopefully no 'residue'. Yes - it looks like a Kenton kit, on both units. Need to upgrade that. No sys-ex? yuk.

Yes, my wife is wonderful (.)!! She is having fun razzing me right now. That would be crazy if that Expander went for $6800 on ebay. How do I find an internal serial number on a Chroma?

In the store I was staring at the Expander (mulling over life, etc.) and the store guy said 'and I have a Chroma in the back room that 'smoked' up on us...want to see that?'). I was really surprised to see the orange-ie front panel. He was just kind of spinning the leaning Chroma around on its scratched up side panel (ouch). -Brian

David Clarke [21030085++] · Wed, 27 Feb 2013 13:27:38 -0400

Re: Chroma and Expander

... How do I find an internal serial number on a Chroma?

If present, it is generally written in marker on the raw wood on the base of the chassis, near the channel card motherboard, usually near the back cover. With reference to this picture:

internalcablerouting

you can see the 21030085 serial number written in the lower left-hand corner.

(The same idea should be true for both the Exander and the Chroma).

Some other examples from the registry:

Marais · Wed, 27 Feb 2013 13:04:49 -0500

Re: Chroma and Expander

could someone buy David a pint please : ) m

David Gowin [21030611] · Wed, 27 Feb 2013 10:02:52 -0800

Re: Chroma and Expander

I think a night out with unlimited pints would be a good thanks for all his help and knowledge. And maybe a good curry after!

Marais · Wed, 27 Feb 2013 13:31:04 -0500

Re: Chroma and Expander

you might need a bush pilot to visit him now lol

Nicholas Vining [21030777] · Wed, 27 Feb 2013 15:37:31 -0800

Re: Chroma and Expander

I have now retrieved the Chroma Polaris from Trading Musician. I can't resist a bargain. It seems like it's in good shape, too, other than the one dead voice (which the previous owner has apparently been playing with the old keyboard-and-tape trick).

Paul Tillotson [21030218] · Wed, 27 Feb 2013 23:43:01 +0000

Re: Chroma and Expander

I managed to restrain myself from going in this morning and buying the Polaris by convincing myself that it would need a new membrane. You are kind of ruining it for me... :)

Enjoy it. I'll find one eventually, though the Trading Musician is about a mile from my home and place of business and I actually was a keyboard and PA salesman there for a couple years about 10 years ago.

Chris Borman [21030194+] · Wed, 27 Feb 2013 19:01:52 -0500

Re: Chroma and Expander

If anyone gets that Quadra, I’ll trade my Chroma for it.

Chris Borman [21030194+] · Wed, 27 Feb 2013 19:07:18 -0500

Re: Chroma and Expander

So the Polaris is a membrane pratt-reed?

Howie Shen [21030552] · Wed, 27 Feb 2013 16:20:32 -0800

Re: Chroma and Expander

I phoned Trading Musician this morning when they opened and specifically asked about the Quadra. John, the sales guy, stood at the synth with phone in hand to answer some of my basic questions. Apparently it has been fully checked out by them and is in 100% working shape. All sliders are present with slider caps, and none are sticky/stiff. Cosmetic condition was described as "not mint like brand new, but only a few nicks here and there that make it seem like a 2 year old currently manufactured synth" according to John.

At $2499 I think it's a pretty good deal, considering broken Quadras in decent cosmetic shape are going for $2000+ on Ebay, and recently very clean working ones have gone fore $5500 and (gulp) $7000+.

I already have a beautiful one, but was sorely tempted to grab this one to see if it is even better behaved than mine.

The catch? Apparently the owner of Trading Musician is VERY wary of shipping any of these ARPs, so I was told that unless I had someone local who would pick it up for me (I'm in Los Angeles) they would rather not ship it.

So in a weird way I was relieved to be given that out...otherwise I'd be $2500 poorer right now but another Quadra richer!

Good luck to whomever gets it...the Quadra is one of my all-time favorites.

Chris Borman [21030194+] · Wed, 27 Feb 2013 19:53:55 -0500

Re: Chroma and Expander

I still have my front panel upgrade design where someone local could help with that dev project. Already have an interface cable to test CPS Kits via my PC and Microchip FS USB Demo board. Really like to see a Quadra...

Paul Tillotson [21030218] · Thu, 28 Feb 2013 00:59:59 +0000

Re: Chroma and Expander

I have 2 Quadras and the one that's supposed to be the fully functional one now has a couple dead keys and there are several notes that sustain after releasing the keys. I need to get it worked on again. I guess I haven't been following current prices but even at a bargain price of $2500 I find it expensive at least compaired to an under $1000 Expander or a $200 Polaris. I have always been obsessed with the Quadra but $5500 or $7000 for one? It's not even a real synth in many ways: it's a cynically designed market driven synth sandwich with some accidental magic built in. I'll probably be thinking about more Quadras tonight.

Paul Tillotson [21030218] · Thu, 28 Feb 2013 01:04:54 +0000

Re: Chroma and Expander

The membrane I was referring to was the control panel not a pratt read membrane keyboard. The Quadra, ARP electric piano(?) and the Chroma/Expander and Polaris all used membrane control panels but the Polaris seemed to fail at the ribbon connector much more than any of its ancestors.

Chris Borman [21030194+] · Wed, 27 Feb 2013 21:06:54 -0500

Re: Chroma and Expander

Right! I’ve got membrane keyboard actions on the brane ...

Paul DeRocco [21030230] · Wed, 27 Feb 2013 18:45:28 -0800

Re: Chroma and Expander

From: chrisborman

If anyone gets that Quadra, I'll trade my Chroma for it.

You'd trade a Chroma for a Quadra? Are you insane???

;-)

Doug Terrebonne [21030114] · Wed, 27 Feb 2013 21:38:07 -0800

Re: Chroma and Expander

Heh, yeah it seems insane to me too. Kinda like trading a 2600 for an Omni... :)

Jesper Ödemark [21010135] · Thu, 28 Feb 2013 10:19:03 +0100

Re: Chroma and Expander

chrisborman skrev 2013-02-28 01:01:

If anyone gets that Quadra, I’ll trade my Chroma for it.

Heresy! ;)

Brian McCully [21030361] · Thu, 28 Feb 2013 14:15:55 -0800

Re: Chroma and Expander

Ok - I have mostly tracked down and figured out what these two units are, or what they contain, as I opened them up too.

  1. The Expander is [1633]0120, it has been upgraded with a CC+, hence the previous registry listing with the Syntech interface and the Li-Ion battery is no longer applicable (yay). My confusion with which MIDI interface it had was because my Chroma with the CC+ has the cable with the little 3 MIDI DIN box, whereas this had an internally mounted set of 3 MIDI DIN's. There is a fan / older power supply, and the ambient noise sounds like a small refrigerator (which I could not hear in the store, but it is quite noisy in a quiet studio), so the first consideration is in swapping out the power supply and/or just yanking the fan. Anyhow. it's in great shape, and probably a keeper, sorry. And there's a good chance that Josef Zawinul played a few tunes through it...
  2. The Halloween paneled Chroma with no serial number is indeed the "Halloween" Chroma on Craigslist Denver" (on the forum dated June 23, 2011, with previous listings as well). The pictures match, with the 'Condor' labeled PS inside (with $30 sticker) and the off-color keys next to the cheek blocks. The top metal panel has a fan hole over the PS area, but no fan. The wood side panels are pretty scruffed up. And...it is a pretty unique looking unit with the 'candy corn' color scheme. (I have an extra blue green color scheme panel with 'ARP CHROMA' on it (vs. just 'CHROMA'), but this instrument's panel doesn't say ARP - I wonder what the production timeline for this color scheme was at ARP, and Fender?).

The CL ad stated at that time it had 'a MIDI interface', whereas now it actually has both a CC+ and a CPS kit - again quite a surprise when I opened it up (it has three generic I/T/O labeled MIDI DINs on the back). I was told it had just 'smoked up' before I purchased it (the salesperson said it was still sounding fine even while it smoked) so they just yanked the 115VAC plug and put it in the back room of the store, and I think I bought it the same day. I have not attempted to turn it on, but it sure smells like a burn in the PS area. Visual internal inspection didn't yield a clue about what fried. I'll see how far I get with repairs and some other updates, then consider the next options.

Both instrument's CC+ firmware chips were v2.15 from May 2011. regards, -Brian

Ron Joseph [21030042+] · Thu, 28 Feb 2013 19:09:01 -0500

Re: Chroma and Expander

There's quite a bit of information about the various panel schemes on the site. Summing it up: 2 membrane types and four possible overlays. Halloween panels came at the end of the Chroma production run and were a very limited prototype run.The miscolored keys makes me think that the keybed at least came from one of the first fifty Chromas,more than likely the whole synth. Originally, all the keys were white but the main part of the keyboard turned yellow the way a lot of old computer plastic did. The end keys are not a standard key shape and must have been produced separately and from different materials. (I've wanted to try the "whitening "trick I've heard about online and try to bring the yellowish keybed back to white). The second run must have used a different keybed as it doesn't exhibit this quirk...Ron

Brian McCully [21030361] · Thu, 28 Feb 2013 17:35:43 -0800

Re: Chroma and Expander

Thanks, Ron. The site is awesomely quite comprehensive but I'm typically only browsing for more immediate needs. I also now see quite a few discussion links from the past owner(s) of this Chroma. I'm just trying to figure out if there's anything special about the unit other than the non-standard power supply and the panel. I found a link that stated it was basically a stock unit.

And your contributions on the panel colors was interesting. Possibly I maybe have a (non-functioning wall art) ARP CHROMA panel prototype from the very first Chromas, and now the the orange/yellow panels from the last run (but they weren't officially released) pre-Polaris.

Chris Ryan [21030691] · Thu, 28 Feb 2013 17:39:18 -0800

Re: Chroma and Expander

See Chroma Panel Colour Themes.

Paul DeRocco [21030230] · Thu, 28 Feb 2013 19:05:50 -0800

Re: Chroma and Expander

I've got one of the prototype Polarises, but mine has all the correct labels on the switches, because those early guesses as to what the switches would do were corrected by sticking new labels over them. The stick-on labels had the correct font, so Rob Witt must have made up a sheet of them for just that purpose.

Also, I never noticed in that page the mention of a POLY/MONO parameter in place of FSW MODE on the original Chroma. I have no memory of any such thing--and I designed it. That must have been another "guess" as to what the switch would do, which got implemented differently when I wrote the firmware.

Go to next message in thread, March 2013

My sad Chroma story

Antoine W Caron [21030234] · Tue, 26 Feb 2013 21:59:47 -0500

I'm glad I found this site...and my Chroma original bill. I purchased Chroma sn 21030234 on July 9, 1984 at Steve's music store in Montréal. It was a dream come true. I sacrificed a lot to get it. I used it for a few years with my band RedShift and for solo projects after. Of course, it eventually started acting up and i got it serviced by a "reputable" tech guy (name available on request!). He fixed it real good and I kept using it for a while.

A year or so later, the Chroma went bad again: it powered up but made no sound. I took it back to the "reputable" guy. He looked at it and said he needed to find some parts for it. I waited and kept calling him regularly. I trusted him because he had previously fixed it well. A few months passed (I know, i wasn't very clever). I finally got tired and called him to say i was going to come and take it back. To make a long story short: the guy had divorced, lost everything (or so he said...). He blamed his ex wife, said he didn't know where the Chroma went, etc, etc.

So , if anybody comes across Chroma #21030234, this is the one that was stolen from me. FWIW, I saw that it is not in the register. I still have the case (complete with molten foam!), the pedals, the Chroma interface and an Apple IIe clone, a Syntech Chroma converter, various eproms from ealier operating system and all the manuals. I have the original bill. Any help appreciated.

Antoine W Caron [21030234] · Wed, 27 Feb 2013 20:44:46 +0000

My sad Chroma story part2

I wish to elaborate a bit more on my previous post (I tried to keep the first one short). Firstly, I don't really expect to recover my Chroma after all that time. Also, a bit of context may help to clarify how I could be robbed so "easily". This happened way before the recent "vintage synth" craving and the "back to analog" madness. At that time, a broken Chroma wasn't worth much and it was nearly impossible to find somebody to fix it. Now, a malfunctionning Chroma can sell for 3-4k on Ebay. All those options now available to restore and modernize it did not exist. Finally, I was going through difficult personal problems when those events took place. If it happened today, I would find the guy and... well get my instrument back one way or another...

Anyways, I guess my options now are the following:

  1. Find a relatively inexpensive Chroma in need of repair and missing all the accessories I already have and get if fixed properly (tough luck!)
  2. Try and sell all my Chroma accessories.

In the likely scenario that I pick option2, I would like to know from all you "up to date" Chroma fans what those accessories are worth (if anything) and if anybody on this list is interested in anything. Otherwise, I guess there is always Sh*tBay. To recap, I still have:

  • Chroma case (in need of removing old foam, cleaning and re-foaming)
  • Chroma Apple II interface, two multipin cables (I use to also have a Polaris...that I sold)
  • Apple IIe clone with 2 disk drives
  • Syntech (Chroma cult?) midi converter
  • various eproms, including one that says "rev 14"
  • the 2 Chroma pedals (twin brass switches and volume)
  • patch cassettes and all manuals

Any help appreciated

PS: I am subscribed to the digest, so I may not be aware of early replies to my first post.

Paul Tillotson [21030218] · Wed, 27 Feb 2013 23:36:55 +0000

Re: My sad Chroma story part2

I suspect that many of us Chroma owners now have unused Chroma Cult MIDI kits and partially working CPU boards and old wonky power supplies sitting around. Refoaming an anvil case for sale would eat up any profits that might be made from selling a road case that would go for under $200. It's a brave new world for the Chroma and it's hard to look at any dead Chroma as an unfixable parts machine to be abandoned on a tech's bench. Some of these parts should trickle down to folks that don't want to invest in the new Chroma replacement parts designs but then again the new power supply and CPU+ are pretty reasonable and easy to install.

Next: save the PolyMoog. Or maybe the Synergy.

Mark Yurkovic ("Shecky") · Thu, 28 Feb 2013 12:18:10 +0000

Re: My sad Chroma story part2

sigh.............I wish I had the money they're asking for it..........I was an original Chroma owner back in 1984............used it all the way through music school. I went to Berklee...........

Had it for years, just couldn't keep it running, or find anyone that could........... Now I collect synths, have just about one of everything, but a Chroma!!! I have a Polaris I found for $100 and it works great...........

Maybe someday......but they seem to go for several thousands of dollars now.......

Antoine W Caron [21030234] · Thu, 28 Feb 2013 14:23:20 -0500

Re: My sad Chroma story part2

I feel your pain Shecky. At least, it makes me feel a little bit better that someone else has a comparable story. Maybe we should form the " Club of Sad ex-Chroma owners" ;) Or the "Club for Hopeless Reunion Of Mortified Analogs !!!

Seriously, I look back at some stuff I did with my Chroma system and it still blows my mind. Like multi-track sequences on the Apple II with both the Chroma and Polaris going multi-timbral. I even used the Chroma+AppleII sequences live (1984, RedShift Subunit: just me and the late Ian Stephens). A favorite of mine was to use a split on the Chroma: the lower keyboard feeding its output to an MXR Distortion + for massive power chords, and the upper keys going to a BigMuff for distorted soloing. Insane fun.