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ChromaTalk Archives: April 2007

Re: MIDI Controllers

Go to first message in thread, March 2007

David Clarke [21030085++] · Sun, 01 Apr 2007 15:17:53 -0400

Andrew Dalebrook [21010180] wrote:

...Behringer BCR-2000 (a MIDI knob box) through the KMX interface,... Because each CC edits one parameter on one voice (A or B) only, you would effectively have to edit each parameter twice, one for the A voice, one for the B. Whereas editing both parameters on the Chroma directly is accomplished by pressing both "Edit A" and "Edit B" simultaneously. Is there a certain trick to merge CCs together, perhaps in software?

Andrew - there's no feature in the Chroma/KMX itself, as it truly treats the A & B parameters as separate entities.

It's clearer to see why they'd do this when you consider a voice architecture/patch mode which isn't 16-channel mode/independent channel mode. For instance, consider a mode like Parallel Filter mode, with Cross Mod. In that configuration you probably really wouldn't want to manipulate A and B at the same time, since they're really controlling different elements of the sound.

Software control surfaces (the faders view in Cakewalk, for instance) do allow controls to be linked together so that when you move one slider (e.g., the "A" slider), other sliders can also move (e.g., the "B" slider).

Or could this be an addition to the CC+ soft/firmware?

It is technically possible to have the CC+ modified to do this, but it would be an open question to the group whether this would be generally desirable feature.

Andrew Dalebrook [21010180] · Wed, 4 Apr 2007 01:27:05 +1200

When I bought my Chroma almost a year ago, I said I would be buying a Behringer BCR-2000 to use for patch editing. I got the BCR a few months later, and it was sitting around, until now. Note: I do NOT work for Behringer!

Basically, I have programmed the BCR to edit parameters on my Chroma, and I think it works very well. Even though I have the KMX interface, which only offers a subset of controls to edit, it will do for now; until I can afford a CC+ (!).

The basic MIDI setup I have been using goes: BCR-2000 (MIDI)-> Midisport 2x2 (MIDI)->Chroma (MIDI)->BCR-2000 (Midisport 2x2 (USB)<-> Toshiba laptop).

If anyone has a BCR-2000, or is planning to get one, I have programmed the knobs on my unit and dumped the sysex files, which I have provided as "BCR2000P1EditA.syx" and "BCR2000P2EditB.syx". By loading the sysex files onto the BCR, you edit the "A" parameters with P(reset) 1 and the "B" parameters with P(reset) 2.

All parameters on the knob controller are outlined on the provided Schematic. They are approximately arranged by row. Werner was saying the other day that his external controllers don't work because the ranges are too short (for example: resonance = 0-7). This is not a problem with the BCR, because you can adjust the minimum and maximum values as you wish. So, "resonance" really has values 0-7 in equal steps upon turning the knob fully clockwise.

The problem arises when the MIDI data is fed into the Chroma. Ken explains he made the interface so you could send CC for bipolar controllers (like Mod Depth), but for the other parameters, you are effectively wasting half your knob or slider.

So, I used the MIDI map function of MIDI-OX (A freeware MIDI utility program that the author asks you pay for if using professionally, http://www.midiox.com ) to translate the "real" values into CC data that the KMX interface can understand:

MIDI-OX.exe -> Options -> Data Mapping... -> Load "Map BCR to Chroma CC" (Check the box that says "Turn on MIDI mapping...")

This will work whether P1 or P2 (on the BCR) is selected.

The way the map works is by converting any MIDI message to any other. So say CC#10 (Pitch Tune A) changes from values 0 to 63 on the BCR. The map will output CC#10, values 64 to 127 to the Chroma.

The second issue, as I alluded to a few weeks ago, is that sometimes you want to edit the A and B parameters simultaneously. Again, I have found a way to overcome this, with a MIDI map:

MIDI-OX.exe -> View -> Port Routings... -> Right click on the routing that is between the BCR-2000 and the Chroma; select Properties -> Select "Map file" drop down box; select "Map A to B" (Check the box that says "Turn on MIDI mapping...")

Note that this second map receives "corrected" CC data (from the first MIDI map). For example, say CC#10 (Pitch Tune A) changes from values 64 to 127 from the first MIDI map. The map will then output CC#10 (Pitch Tune A), values 64 to 127 AND CC#11 (Pitch Tune B), values 64 to 127 to the Chroma.

Again, this works whether P1 or P2 (on the BCR) is selected.

What I then do is save the different presets in MIDI-OX. So, I load the map file "Map BCR to Chroma CC" as shown above and then:

MIDI-OX.exe -> Options -> MIDI devices; Save preset (e.g. "Edit A or B")

Then, keeping the first file open, I load the map file "Map A to B" into the Port Routings as shown above and then:

MIDI-OX.exe -> Options -> MIDI devices; Save preset (e.g. "Edit AB")

Depending on whether I want to edit individual or both parameters, I load the appropriate file.

***

It would also be possible to translate the CC data values sent from the Chroma, via another map file, back into the BCR (so that recognised parameter changes made on the Chroma can be seen as moving the knobs on the BCR), but I have not done this.

So even if you don't have a BCR-2000, you can possibly follow a similar train of thought for use with other controllers. I am unsure exactly how the MIDI implementation for the CC+ works, but perhaps people can use mapping to edit both the A and B parameters (or even multiple parameters!) at once.

I'm probably the only person using a PC for music! Perhaps there is software for Mac which can map CCs in a similar way.

I also agree with Werner that sending the CC values upon changing a program would be very cool, as it would adjust every knob on the controller to the actual values...

Files:

E&MM Peter Vettese Interview Excerpts

Chris Ryan [21030691] · Sun, 1 Apr 2007 22:40:04 -0700

New on the site this month, excerpts from an interview with Peter Vettese, who played the Chroma with Jethro Tull and Ian Anderson in the early 1980s. Perhaps most notable is that he hints at future directions for the instrument/platform; there have been suggestions that he did a promotional video for the Chroma, so may have had some inside information. Also, he is holding a Polaris on the front cover of the magazine; I'm not sure when that keyboard was released, but I thought it wasn't until 1984. It does appear to have the production prototype panel scheme.

Update on Site Expenses and Donations

Chris Ryan [21030691] · Sat, 7 Apr 2007 15:22:58 -0700

Back in the fall of 2005 I set up a PayPal donation system for the site. I really appreciate the donations that have been sent! It has made a real difference. As the hosting account is up for renewal, I thought I'd let everyone know where the fund stands.

To date I have received US$265 in donations. The exchange rate has changed significantly in the last year and a half, with the Canadian dollar strengthening against the US, but if I calculate based on a rate of 1.15 then this is approximately CAD$305, which is equivalent to about two years of hosting. So hosting costs are covered up to this fall, if I begin counting at the time I began accepting donations.

The only other significant and direct expense I think I've incurred was scanning for the Service Manual schematics last summer. As the schematics are oversize and detail is important, I opted for professional scanning, which cost CAD$126.08. Of course, I had originally set out to cover just the hosting costs via donation.

A few of you have attempted to donate but could not because you didn't have a PayPal account, or it wasn't verified; I've never been clear on exactly why. I've considered upgrading to a business account, which would have enabled these people to donate; perhaps I will do that, although there are fees (a percentage of each transaction).

This e-mail is for informational purposes only and is not intended as a solicitation. :)

Peter Forrest [21010096] · Sat, 7 Apr 2007 23:38:45 +0100

You deserve all the donations and much more, Chris! Thanks for the fantastic work you put in. I guess it might be worth upgrading to a business paypal account - 4.5% or whatever is expensive, but it would probably make sense.

Fwd: chroma hard program re-flash

Chris Ryan [21030691] · Mon, 9 Apr 2007 17:23:21 -0700

Does anyone have some advice for Todd?

Begin forwarded message:

I work in the repair department at Quickbeam Systems, Inc in Albuquerque, NM and am repairing a Chroma 2103 [21030077] that came in with a dead power supply, which I've fixed. I have no sound coming out of the output, despite having voltage being transferred at the keys switches. Voltage at the computer board is 4.99v. It seems like everything is fine voltages-wise, so I was wondering if you've seen hard program chips (e-proms in the computer board) being erased when the main power supply cap goes bad and who to contact if I need them re-flashed.

I appreciate your insight,

Todd Tijerina

Ron Joseph [21030042+] · Tue, 10 Apr 2007 18:32:41 +0000

Check the simple things first: (Parameter 5) How are your outputs assigned ?Is the dummy plug in the right output? Did you lose all your patches? Reload them and then check for mechanical issues. Good luck...

Werner Schöenenberger [21010114] · Tue, 10 Apr 2007 21:20:07 +0200

I also doubt that there is a damage to the EPROMS. They normally do not die due to low voltage... If the Instrument powers up normally and no bad voices are shown, then I would look in the output section. If it does not power up, maybe it can be the battery thing or the microprocessor or the clock generator...

Quickbeam Systems · Wed, 11 Apr 2007 10:00:39 -0600

no audio output

i am not getting any audio output. the power supply was damaged because of a bad cap and fixed. all chips have the correct voltage according to the proper values stated online and in the schematics. is it possible that when the power supply blew the fuse it could have erased the eprom chips z-29 thru z-36? all other functions are working; LEDs, function keys, etc. i have gone through all the troubleshooting directives and still no sound! also when turned on no errors are being displayed in the 'data readout' screen. i can cause an error by unpluging components to make sure that it can read errors but when made to be 100%, no errors and no audio output! the SN #21030077.

thanks

Randel Osborne [21030467] · Wed, 11 Apr 2007 12:23:29 -0400

Re: no audio output

The eproms hold the instructions for the microprocessor, so the front panel would not function if they had failed.

I'd listen to the output with a high gain - if the EQ affects the very low signal noise of the instrument when it is on, you have eliminated the EQ and output circuitry as points of failure.

If the display blinks 16 times upon powerup, and no errors are given, the voice cards have passed autotune, and are functioning.

I might have a look at the keyboard scan - the stack switch boards, and the keyboard scanning portion of the I/O card.

If the unit is fitted with a MIDI interface, you could determine if it plays via MIDI.

Dave Bradley [16330135] · Wed, 11 Apr 2007 12:51:40 -0400

Re: no audio output

Do you have service schematics? Backtrack to the audio outputs of the individual voice cards and see if you have audio there, then move forward to the output board. It could be as simple as a bad opamp.

Chris Ryan [21030691] · Wed, 11 Apr 2007 09:57:51 -0700

Re: no audio output

Do you have service schematics?

The schematics are available at the site.

John B. Rotondi [21030185+] · Wed, 11 Apr 2007 14:29:49 -0700

Re: no audio output

Hi!

There are many members more knowledgeable than I about the inner workings of the Chroma, and it has been a while since I've used mine- but If I may interject here to reiterate what I believe another member may have mentioned, and which might have been missed by someone who does not normally work on such programmable musical instruments- btw, no assumptions being made here, but I hadn't heard of the service person in this matter mentioning investigation of this particular issue, which may have such symptoms, but not be related to the original loss of the power supply:

The Chroma may be functioning 100% correctly- but might have lost the stored voice programming NMOS memory that contains the values for the 100 parameters comprising each of 50 'patches' that actually cause the voices to produce sound. I believe an empty patch produces a null output, if I recall correctly? This is volatile RAM that is battery backed. Are these two AA batteries intact and functional? People often forget to replace them in time. There is a [SET SPLIT] parameter that queries the battery voltage, but I would put a voltmeter across them directly and check. If the batts are dead, then there are no stored patches to tell the voices to make sound, so there should be no sound- as with any computer, it just does what it is told!

You can program in a basic patch manually and attempt to play it, or load through the cassette port if you have a Chroma programming tape available.

If the batteries check good, then you might want to (looking at the schematic) place a scope on the voice card (#1 to start) and hit a key, and see if you get a waveform at the 'A' Voice VCA input- then at it's output (which is the A/B VCA Sum point)- then at one of the outputs of the 1 of 4 audio buss selector, where it leaves the card. All these items are programmable, based on patch parameters. If signal gets off this card, then the unit IS producing sound that you should be able to hear at the main mono output if everything is functioning normally, and the various volume parameters and controls are turned up. You can then trace it through the audio signal path to see where it ends up... but if there is no output from the dual channel voice boards, then the problem is probably not audio related, but most likely logic or interface related, IMHO.

I hope this information is helpful.

Regards to all Chromaphiles- and thanks to Chris and the CC+ team for all the continued great work!!

Ron Joseph [21030042+] · Wed, 11 Apr 2007 22:57:44 +0000

Re: no audio output

That was me. I had a similiar issue w/ one of mine. Had an issue w/ the power supply and when I fixed it...no sound. Turns out the patch memory was wiped.

Second screw up was my mis- use of the dummy plug. Audio was routed to a different output....also managed to think I had a non working board when I accidently changed Parameter 5 ( Output select ).

Simple stuff for those who are very familiar w/ the Chroma but enough to stump me several times.

Quickbeam Systems · Tue, 17 Apr 2007 14:46:33 -0600

Re: no audio output

hi john,

i think we have narrowed it down to the VCAs not getting voltage to turn on so therefore, no output. what does the voltage need to be @ TP1 and TP2 on the I\O board? is that even where we might measure to solve this problem? everyhting else is working and has proper voltage according to info we already have. we see signal throughout the channel boards.

John Leimseider [21030434++] · Tue, 17 Apr 2007 15:20:59 -0600

Re: no audio output

You should really look at the output of the DEMUX'es for volume on the individual voice cards. You won't be able to tell which voltage is which on the DAC output unless you sync it to something that aligns the time to something known... Do the oscillators track the keyboard pitch? Since each voice card has separate control, it doesn't make sense that none are working and it's just the volume CVs... Are you sure that you have valid patch data? Have you set it to a scratch patch?

Quickbeam Systems · Tue, 17 Apr 2007 17:25:57 -0600

Re: no audio output

there is signal all the way to Z16A but nothing is coming out of the chip. i'm not sure if the patch data is good. i do not know how to set it to a scratch patch. the display does not indicate any errors, so i am assuming the voice cards are in working order. i also do not know if the oscillators are tracking the pitch. how do you test for that?

Dave Bradley [16330135] · Tue, 17 Apr 2007 20:51:12 -0500

Re: no audio output

See Calibration and Checkout, 7th paragraph for instructions on setting up a scratch patch. It is absolutely essential that you start from reasonable default values when testing for sound.

John Leimseider [21030434++] · Wed, 18 Apr 2007 07:35:09 -0600

Re: no audio output

You should read the owner's manual on the website for the scratch patch. It's very possible that nothing is wrong, except the memory is wiped. That's what I suspect.

Ron Joseph [21030042+] · Wed, 18 Apr 2007 15:10:08 +0000

Re: no audio output

Hey John,

I recommended that as well. I don't know why he hasn't ruled it out. There's a bank of patches on the site in wav. format ( I think). Maybe someone w/ better computer skills could post a direct link w/ some instructions on how to load it. Hopefully it's something that simple.

As an aside, thanks for your help on the power converter problem.Much appreciated :)

Quickbeam Systems Vasquez · Wed, 18 Apr 2007 13:04:26 -0600

Re: no audio output

hi john,

that is what we have come to suspect now as well, thanks for the tip. we have got audio output but no programs. we hear white noise and are able to make some parameter changes. how can we get the original programs into the unit?

Chris Ryan [21030691] · Wed, 18 Apr 2007 13:11:33 -0700

Re: no audio output

Does the Chroma have a MIDI retrofit or CPU Plus? If so, then you will need an app or utility to send sysex [Mac OS X, Windows]. Lots of patches can be found at the site. If you have to load via audio, use the Factory 5 set available in .wav format, or convert other banks from sysex using the conversion tools.

CC+ and SPSU on my Chroma

Luca Sasdelli [21010226] · Sat, 14 Apr 2007 11:43:44 +0200

Hi all,

at last, I've installed both new CC+ and SPSU, after a couple of years keeping instrument stored. I've also taken the keyboard apart, vacuumed the case, re-routed most of wiring, cleaned contacts and connectors all around.

Now my Chroma is re-born, CC+ works great and I'm impressed by the MIDI implementation; simply I connect my laptop with plenty of VSTs and the monster is now unbeatable.

Best compliments to Sandro and David for the big job!

CC+ Remote Control (Program and Instrument CC Modes)

Go to first message in thread (March 2007)

David Clarke [21030085++] · Sat, 14 Apr 2007 09:59:08 -0400

Werner Schöenenberger [21010114] wrote:

Additionally I do not understand the need of the different MIDI CC mode (P24). In my opinion only the "Prog" mode is needed since all changes to Prog 0 are gone whenever a Program Change is made (as long as there was not a patch save done before). What is the advantage of the "Inst" mode?

There was a couple thoughts behind the Inst mode.

First, that is the mode that the KMX/Syntech interface uses - so to keep an equivalent mode of operation we wanted to keep it.

Second (at least for me) it comes in handy because its 'non-destructive.' On those occasions where I've modified a sound to something I like (e.g., from the front panel), but not stored/saved it yet - any changes via CC in Prog mode could get me to a point where I couldn't easily get back to the original patch. This isn't an issue in Inst mode.

Perhaps the biggest reason "Inst" (Instrument) mode is present though is its ability to modify the behaviour of more than one instrument on the Chroma.

If you're in 'Prog' mode - the cc's you send can only manipulate those Chroma sounds which as based on Prog 0. This is great if only one patch is intended to be tweaked on the Chroma.

If however you want to have several different voices simultaneously sounding on the Chroma (e.g., Patch 12 on Midi channel 3, Patch 19 on Midi channel 4, Patch 45 on Midi channel 5, etc.) and you want each of these patches dynamically changed/tweaked (e.g., via sequenced data on a computer), then Inst mode will allow this to be done.

In summary - Prog mode will only affect Prog 0, whereas Inst mode will affect the currently actively 'Instrument' on the given Midi channel. Prog mode would seem to be most useful when editing/creating a patch, whereas Inst mode is often more appropriate during playback/sequencing.

David Clarke [21030085++] · Sat, 14 Apr 2007 10:02:22 -0400

re: CC+ Remote Control (Auto Parameter-Send by CC)

Werner Schöenenberger wrote:

  1. Parameter-Send by CC

    A further mode would help users of controllers with automated faders (or belts). If there would be a mode which sends all parameters as MIDI CC commands when a patch is selected, the attached device would be able to adjust faders and pots to the current sound. This would make it easier to make small changes to the sounds and would give an overview of the parameter settings. Maybe this mode also could be switched on/off with a CC+ Parameter (e.g. P27)

Any comments from other CC+ users (or folks perhaps considering a CC+)? Is this a feature you'd like to have?

Åke Danielson [21010068] · Sat, 14 Apr 2007 17:04:31 +0200

Hi David,

I think that the Parameter-Send would be a great features for computer editors. The actual settings of a sound could then be shown to the user for a better overview. Switchable (ON/OFF) to avoid congestion when not needed. Also the Sysex-Send of the current sound using a switch would make storing sounds together with their songs much easier.

Fredo Fraile [21040011+] · Sat, 14 Apr 2007 17:13:43 +0200

Any comments from other CC+ users (or folks perhaps considering a CC+)? Is this a feature you'd like to have?

YES YES YES,i would like to have it!

Werner Schöenenberger [21010114] · Sun, 15 Apr 2007 21:56:05 +0200

There was a couple thoughts behind the Inst mode. [...]

Hi David,

well - this is enlightening ;-) . Everything is reasonable - I simply did not think that far. Thank you for making things clear.

Chroma 21030016 on craigslist

Chris Ryan [21030691] · Tue, 24 Apr 2007 09:22:45 -0700

"Offers until midnight 24 April 2007."

URL removed. Excerpt from the posting:

This unit has the original ARP (says ARP on them) Voice Cards without the Rhodes logo on the back panel. This unit was recently serviced in Oakland CA and upon delivery, it was DOA (all blame to FedEx). It was just serviced by a technician who used to service YMO's gear. Works great. The background on this unit can be found in the Rhodes Chroma archives here. I was able to get my other Chroma working, and, although this one is nicer cosmetic condition, I'm sticking by my first one. There are two cosmetic issues: 1) some scratches on the top panel (new coat of epoxy will do it, maybe). and one replacement key of a different hue (at the top of the scale). Pictures can be found here.

Dave Bradley [16330135] · Tue, 24 Apr 2007 11:39:12 -0500

Looks like the volume slider is broken off.

Greg Montalbano, Analog Synthesizer Service · Tue, 24 Apr 2007 09:51:13 -0700

Just FYI, I'm the one who serviced this unit --- received it dead, repaired it & sent it to NY from CA (during which time it stopped working again -- these things really don't travel well). This is from my notes on what was done to it:

Ended up doing repairs on 6 of the 8 voice boards, rebuilding the CPU board (due to battery leak damage), doing extensive work on the I/O board, replacing the volume pot, replacing some dead ICs on the channel mother board, tweaking the power supply...

I've spent the day testing all the functions, and it appears to be intact; the only thing that's not right is the large LED display -- one segment of the left digit is burned out. This only shows up on the left digit 2 (i.e., programs 20 - 29); you can still tell what it's supposed to be.

Anyone with access to LOCAL service (or anyone who is sufficiently capable of working on it themselves) might want to check this unit out.

Chris Ryan [21030691] · Fri, 27 Apr 2007 18:45:38 -0700

The instrument was listed on eBay: item #120113851418, but apparently the auction has already ended; perhaps someone paid the "buy it now" price of US$3499.

David Clarke [21030085++] · Fri, 27 Apr 2007 23:21:47 -0400

It looks there was just an update to the listing, and it is now under a different number:

120113884894

Current bid is $305.00 USD.

setting up midi control

Jesper Ödemark [21010135] · Wed, 25 Apr 2007 20:22:34 +0200

Hi List!

My Doepfer Drehbank arrived today and I'm in the middle of mapping that the way I want it. My plan is to have each bank to correspond with each oscillator set (A vs. B) and the five first controls on the chroma appearing in both banks. I'm mapping the Drehbank like this;

Bank A (knob numbers)
Control (1-5) Glide (6-7) Sweep (8-12)
Envelope 1 (17-22) Envelope 2 (23-29)
Pitch (33-39) Waveshape (40-43)
Cutoff (49-57) Volume (58-62)

Bank B
Control (65-69) Glide (70-71) Sweep (72-76)
Envelope 1 (81-86) Envelope 2 (87-93)
Pitch (97-103) Waveshape (104-107)
Cutoff (113-121) Volume (122-126)

But then I run across this in the manual of the CC+; "The default MCM which is installed with Enhanced Programming (Set Split 36, P20) is below. This map attempts to provide a direct mapping for all the standard front-panel parameters on the Chroma."

How am I suppose to interpret it (moron alert!)? "Set Split to the value 36 and then press button 20"?

I'm a knob fiddler, no button presser. Help! ;)

Werner Schöenenberger [21010114] · Wed, 25 Apr 2007 20:57:11 +0200

Hi Jesper,

well, even if I did not change any MCM until now, I interpret it as following:

  • With "Set Split" and parameter "36" at the same time you enter the programming mode of the CC+. If you press "Set Split" and "36" again, you leave the programming mode. Pressing "Set Split" and "36" again you re-enter the programming mode.
  • In programming mode, pressing parameter "20" will initialise the MCM to the default settings.
  • If you want to change the default parameters at your wish (e.g. as described in your list below), you have to press parameter "19" to enter the "edit MCM" mode.
  • In this edit MCM mode, the display will somehow show like "C013 009" which means that controller #13 is linked to Chroma parameter #9 (see list in the manual)
  • To select the controller id, you press "Edit A" and with the slider you select the Controller. "C013" will move to anything you select.
  • To select the Chroma parameter, you press "Edit B" and with the slider you select the parameter number. "009" will move to anything you select.
  • Now you can edit the list at your wish. I think it is a good idea to make notes about your changes.
  • Pressing another parameter, e.g. parameter 7 or press "Set Split " and "36" will leave the edit MCM mode.

So if for example you want to configure the MCM that "B-Glide Rate" (which is Chroma Parameter # 056) is controlled by Controller #70, as assumed by your list below, in MCM edit you have to

  • press "Edit A" and move the slider until your display shows "C070 xxx", where xxx is any value between 000 and 127
  • press "Edit B" and move the slider until your display shows "C070 056"

Then the assignment is done.

Happy configuring ;-)

Jesper Ödemark [21010135] · Wed, 25 Apr 2007 22:10:31 +0200

Thanks Werner... I'll dive into this tomorrow... I'm going to hit the sack now... :)

David Clarke [21030085++] · Wed, 25 Apr 2007 18:04:08 -0400

I'm a knob fiddler, no button presser. Help! ;)

My thanks to Werner as his explanation on how to use the interface was better than I could have put together.

In addition to his e-mail, I can add that if you want don't want to use a 'custom' map and instead want to the default 'enhanced' map on the CC+ (the one referenced in the manual) (and set up a custom mapping on the knob box), then:

  1. Press Set-Split and then press "36". The large LED display should now read "EP"
  2. Press "18" (MCM Mode Selection), and use the data entry slider until the display reads "CUST".
  3. Press "20" (Init MCM), and move the slider (you'll see the 'program modified LED bit flash).
  4. Exit programming mode by either doing Set-Split 36, just just by pressing "36". The Chroma should have its normal display.

After you have done these steps, the Chroma's configuration will be as per the chart in the on-line manual.

Based on your note, you'd like the 5 control parameters to be assigned to Knobs 1-5 (in bank A).

Per the table, those controls are mapped to MIDI CC 115 -> 119, so (if I understand correctly), then on the Doepfer you'd (for instance):

  • Map Bank A, Knob 1 -> MIDI CC 115 (Patch)
  • Map Bank A, Knob 2 -> MIDI CC 116 (Fsw Mode)
  • Map Bank A, Knob 3 -> MIDI CC 117 (Kybd Alg)
  • Map Bank A, Knob 4 -> MIDI CC 118 (Detune)
  • Map Bank A, Knob 5 -> MIDI CC 119 (Out Select)

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 07:15:35 +0200

My thanks to Werner as his explanation on how to use the interface was better than I could have put together.

Yes, I followed that too... I hope I can get a kid-free hour to tweak around with the Chroma settings today.

Per the table, those controls are mapped to MIDI CC 115 -> 119, so (if I understand correctly), then on the Doepfer you'd (for instance):

  • Map Bank A, Knob 1 -> MIDI CC 115 (Patch)
  • Map Bank A, Knob 2 -> MIDI CC 116 (Fsw Mode)
  • Map Bank A, Knob 3 -> MIDI CC 117 (Kybd Alg)
  • Map Bank A, Knob 4 -> MIDI CC 118 (Detune)
  • Map Bank A, Knob 5 -> MIDI CC 119 (Out Select)

...and I'm going to do the same for channel B so that knob 65-69 does the same. Regarding the Drehbank I can also mention that the knobs are spread in 4 lines with 16 knobs in each. At the right end of each line the two last knobs (15-16, 31-32, 47-48 and 63-64) has inputs on the back for control voltages too. Therefor I excluded these and apply these later using foot control, midi messages such as aftertouch etc.

When this works it's only "chromifying" of the Drehbank left. Cherry end cheeks and maybe a black panel with blue/green/red/white graphics just like the Chroma. It fits beautifully on top of the program switches section...

Thanks for the extra info David!

Frank Hettlich · Thu, 26 Apr 2007 09:48:33 +0200

Hello Chroma group,

with all the discussion about the possible uses of the Doepfer Drehbank I am wondering if the development of a CHROMA KNOB BOX is still in progress or finally stopped?

See posts from November-December 2006 (DIY solution for a potentiometer interface for the chroma (or other synths)/Some other non diy solution for a fader box).

Sorry if this has been asked before.

Martin Pavlas [21030450] · Thu, 26 Apr 2007 10:45:05 +0200

Hi,

I keep working on it. The only trouble is that I have not enough time to do it faster. You can find a very short story about it at:

http://www.martin.tk/chromanoff/ [url obsolete as of 2009.07; see archive.org version (missing images)]

I have a big deal of software written and tested. Hardware part was tested on pcb-test-boards. I am building the prototype unit these days.

As I worked on the project I eventually decided to build sort-of controller computer that can be extended with modules. The info on the website is a bit outdated. The major change is that it will not use XML for configuration files, as it generates too much overhead. And instead my own scripting language, I am considering using forth interpreter - ie. a very cool programming language from beginning of computer era. By doing this the unit can be programmed to do anything, depending on what program you load from a mmc card. Also, the prototype unit has built-in a USB port.

The cost of components (for core system with chromanoff module, excluding analog CV) and the pcb is below 100EUR. The big LCD plays a big role in it.

Christian Kleine [21030210] · Thu, 26 Apr 2007 10:51:18 +0200

Do you take pre-orders? ;-)

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 10:59:55 +0200

Looks nice! :)

I dig the name too...

Frank Hettlich · Thu, 26 Apr 2007 12:16:19 +0200

Hi Martin,

thanks a lot for replying so fast and in such detail!

Your decision to build a more generic controller is fully understandable looking at all the effort you put into this project.

I am especially pleased to see an optional cv/gate interface as the majority of my synth to synth/sequencer interfacing deliberately uses cv/gate.

As a purist I would have preferred dedicated knobs and buttons (and would even be willing to pay extra for that). But life always is a compromise and I am quite happy that someone like you is offering such a box in the future.

I wish you good luck (and spare time)!

Martin Pavlas [21030450] · Thu, 26 Apr 2007 13:52:23 +0200

Hi Frank,

the system can be easily extended to 24 encoders (if you don't use the possibility to 'click' the encoder), or 16 (if they are clickable). However, adding more encoders would require some redesign of GUI.

I tried to keep it small and rather universal, sort of swiss army knife. I said in past I would dump the info to some website. I am still planning to do it, there would be the source codes, schematics, pcbs, so anybody can branch it to his/her own path.

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 14:13:30 +0200

I don't want to rain on anybody's parade, but the Drehbank is also equipped with cv/gate in... 8 sockets...

jesper - hating the setup, loving the function

Werner Schöenenberger [21010114] · Thu, 26 Apr 2007 22:27:50 +0200

Hi Jesper,

I second the idea of David. Maybe it is much more easier to use the default MCM and just adjust the Drehbank to the MIDI controller expected by the Chroma - this might reduce your effort and maybe can be done with a computer...

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 22:32:10 +0200

It can be done with a computer, there is even a fancy program for it. I just started fiddling with the Chroma 'cause my PC have no midi port. But if I sort out the mentioned midi box problem I might be able to send it to the Drehbank from a friends computer...

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 22:30:46 +0200

Weird midibox

Hi!

I was having some progress with my programming of the Chroma together with the Drehbank but now, all of a sudden, the green LED on the CC+ midi box doesn't light up. It's not the Drehbank 'cause I've tested i from master keyboard, Pocket Dial (basically the same as the Drehbank but smaller) etc and not a glow. The Chroma works as supposed to through the normal EES midi I use though and the CC+ seems fine since all commands I've tested are OK.

Can I have received a "monday copy"? If so, my luck indeed... :) Or can I have overlooked something? I haven't sent anything except CC messages down that line and it worked earlier today...

BTW, the hot swedish summer is coming I can see that 'cause voice board 1 and 7 won't tune... :- /

Werner Schöenenberger [21010114] · Thu, 26 Apr 2007 22:41:06 +0200

Re: Weird midibox

Hi Jesper,

my first guess would be that you modified the MIDI channel. Press "Set Split 36" and then P1 to check if the MIDI channel still is set correct.

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 22:44:24 +0200

is it failing me? *sob*

It's not just the box, no matter which bank I choose I only get sound from patch 14, 15, 16, 48, 49 and 50 and some weirdness on a few in the lower 40's. The sounds are all the same as far as I can judge...

*getting desperate*

What now?!?!

Jesper Ödemark [21010135] · Thu, 26 Apr 2007 22:49:33 +0200

Re: Weird midibox

Damn... that wasn't it and I had checked it...

Adding to the confusion... The mentioned patches that do sound; 48-50 works through midi and fromt he keys, and 14-16 only from the keyboard. :(

I'm off to bed now and maybe some divine intervention will solve this during the night, but to me it sounds as if the Chroma has gone nuts.

David Clarke [21030085++] · Thu, 26 Apr 2007 20:35:50 -0400

Re: Weird midibox

Adding to the confusion... The mentioned patches that do sound; 48-50 works through midi and fromt he keys, and 14-16 only from the keyboard. :(

I'm off to bed now and maybe some divine intervention will solve this during the night, but to me it sounds as if the Chroma has gone nuts.

If problem is still present in the morning:

  • With the power off, disconnect all extra external items (EES MIDI, knob box, etc.)
  • Power on Chroma and check operation from the Keyboard.

If problems are still present:

  • See if a scratch patch outputs the way you'd expect it to.
  • Enter CC+ Configuration Mode (Set Split-36) and take note of the settings for all of the configuration settings (P1 -> P25)

If problems are gone, add each piece of external equipment one at a time to see what might be causal.

Jesper Ödemark [21010135] · Fri, 27 Apr 2007 08:41:01 +0200

patient 21010135

Hi List!

I spent the last hour testing the functions of the Chroma in a sound manner and not like tonight, filled with anxiety and irritation... anyway;

Unplugged it and removed everything except the out-plug. (and power cord *doh* ;) )

  • Autotune is OK
  • the mentioned working patches works from the keys
  • made a scratchpatch and saved it, it works
  • went through most of the "set split" functions - works fine (but I noted a battery drop, yesterday it was 3.02 and today 2.94, still well above 2.5, but I thought I should mention it since there is a problem (see below))
  • fiddled around with the programming - all OK, all oscillators tuned
  • unplugged and added each bit of equipment, one by one;
  • pedals OK
  • EES midi OK (only tested in) (I've not tested loading patches from midi nor cassette BTW)
  • CC+ midi OK (only tested in)
  • Pocket Dial works
  • Drehbank doesn't (but that's probably due to the re-configuration of the Chroma, it still sends midi)

Here comes the big mystery; I cannot change the ROM preset banks. I'm stuck in bank 3 (probably where I were when something went bad). I can save to it and it's still there after power off and on and all tested functions otherwise work.

Can I have sent some bad instruction by accident that somehow locked bank loading and partly cleared the ROM preset 3?! I think that doesn't sound very realistic. Can it be a software bug?

I'm very happy this baby is back in business, I was terrified yesterday that it had died on me. But something is still rotten in the state of Denmark (well, close at least) so all input appreciated. Sandro and David, please let me know if you want me to check something specific. I can handle a voltage meter, but I'm no tech wiz.

Jesper Ödemark [21010135] · Fri, 27 Apr 2007 22:18:46 +0200

Kick the stupid swede

Hi...

Well... I guess I'm not the first and most certainly not the last to embaress myself on the list so here we go; Do _NOT_ press param+bank number with the CC+ when the idea is to press prog+bank number... *doh* That issue solved. *sigh*

But, I did manage to erase those prom memories in some way but I'm not sure how. So tonight I kicked the girl back to life with Matthias Becker's patches I'd kept in the Chroma Editor. I guess taking the factory patches from tape via the Chroma to the Chroma Editor is my next step if I plan to fxxk up again.

Thanks to Werner and others with kind words. I often use the phrase "SBS-fel" which is swedish for "CBC-fault" where CBC stands for Crap Behind (the) Controls. This was indeed a SBS-fel...

I'll probably miss those "Cool Blue" patches though... back to getting the Drehbank to do it's job. Sorry for the wasted band width.

Werner Schöenenberger [21010114] · Sat, 28 Apr 2007 09:56:21 +0200

Re: Kick the stupid swede

Hallelujah Jesper,

how must it feel to be so happy ;-). I am glad with you, the issue is resolved.

Jesper Ödemark [21010135] · Sun, 29 Apr 2007 06:48:13 +0200

Re: Kick the stupid swede

Thanks!

But it would also be cool to know which command I sent cleared the memories...

David Clarke [21030085++] · Sun, 29 Apr 2007 12:36:39 -0400

Re: Kick the stupid swede

But it would also be cool to know which command I sent cleared the memories...

Jesper - there isn't a specific (intended) functionality inside the firmware to clear the memory and so to better understand what might have occurred we'd need a bit more detail on exactly what occurred.

Specifically:

  • When the bad behaviour started, did all the 4 patch banks get affected 100% the same way (e.g., the same patches in each bank worked or didn't)?
  • Did all the patches which made sounds make the same sounds?
  • What version of firmware was being used? ([Set Split][36], P25)
  • What sorts of actions were performed between when the system was last seen to be working vs. when it stopped?
  • Was any other 'bad' behaviour noted before the setup went funny? For instance, did the Chroma unexpectedly reset - did it do something odd in response to a given panel stroke?
  • When the problem occurred, was there data coming in from the Chroma port (e.g., EES midi) at the same time as the CC+ MIDI port?

Jesper Ödemark [21010135] · Sun, 29 Apr 2007 20:03:02 +0200

Re: Kick the stupid swede

Hi David, hi list!

Jesper - there isn't a specific (intended) functionality inside the firmware to clear the memory and so to better understand what might have occurred we'd need a bit more detail on exactly what occurred.

OK, that was my first question. It could be intended I guess. ;)

Specifically:

  • When the bad behaviour started, did all the 4 patch banks get affected 100% the same way (e.g., the same patches in each bank worked or didn't)?

Since I messed it up my trying to switch banks with the wrong button I cannot be sure. I was too hysterical to notice... *sorry*

  • Did all the patches which made sounds make the same sounds?

No, it was as if those six that did work was the right ones. So my first check was that it wasn't just the pedal setting or outputs that was messed up and somehow did affect these six... I also tried some crude mathematics to see if there was some reason these survided. (My OSCar sometimes fails me in exactly six keys which is very logical if you think digital... ;) ) But that didn't help either since it was 14-16 and 48-50.

  • What version of firmware was being used? ([Set Split][36], P25)

2.10? That's what I recall from checking last night. I'll double check next time I'll jump the chic! :)

  • What sorts of actions were performed between when the system was last seen to be working vs. when it stopped?

I was configuring the Drehbank and probably sent far too much info down the line.

  • Was any other 'bad' behaviour noted before the setup went funny? For instance, did the Chroma unexpectedly reset - did it do something odd in response to a given panel stroke?

I know for sure it did an autotune I never requested unless I did so by mistake via the Drehbank.

  • When the problem occurred, was there data coming in from the Chroma port (e.g., EES midi) at the same time as the CC+ MIDI port?

You mean _to_ the ports or what? If so, no, I played the Chroma so the EES wasn't receiving anything.

I'm quite positive that it was me sending far too much info to the poor girl that made the crash happen. But I'll gladly assist in sorting it out if it can be avoided on future software upgrades. But please bear with me when I say I was far too scared I'd messed her up totally to take notice of all minor events...

electronically yours, jesper - just glad she's back...

For sale some Chroma Chips CEM 3360 and CEM 3350

Rob Belcher [16330123] · Sun, 29 Apr 2007 12:34:39 +0100

Hi guys,

Excuse the for sale advert, but im going though my spare parts box and selling off the parts i dont need. Please look at my Ebay auctions. I thought the two auction's for the CEM 3360 dual VCA and CEM 3350 dual VCF would be of interest to Chroma owners. These chips are NOS bought a few years ago and stored as spares- i understand these chips are now getting pretty hard to source.