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ChromaTalk Archives: December 2003

polaris c-key

Claes von Heijne [16330008] · Mon, 01 Dec 2003 12:58:10 +0000

I have a Polaris, the bottom c is broken, I want to replace it, anybody who has a spare part, knows where it can be found, and if the polaris shares keys with other intrument of that era?

all the best

Claes

Fixing Voice Card update

Luca Pilla [21010218] · Thu, 04 Dec 2003 22:32:45 +0100

See original threads Fixing voice cards (September 2003) and Fixing voice card (October 2003)

Hello!

Thanks Dave for your suggestions! I have checked the voice card: here the results

  • Z21 Pin 7 4,89
  • Z23 Pin 1 4,89 It seems ok,
  • Z2 Pin 3 oscillates fast,
  • Z3 Pin 3 oscillates slowly
  • Z3 Pin 1 2,6 mv
  • Z6 Pin 1 oscillates fast
  • Z5 Pin 1 oscillates
  • Z4 pin 1 -3,096 V. Pin 4 -11.84

I check a good working voice card for Z4, not the same of course. I think that one problem of this voice card could be Z4, don't you?

Sorry for delay.

Where should I start for not working cards?

Many thanks
Luca

David Clarke [21030085++] · Sat, 06 Dec 2003 10:27:00 -0500

I check a good working voice card for Z4, not the same of course. I think that one problem of this voice card could be Z4, don't you?

Pin 4 is intended to be the negative power supply rail, which in this case should be -12. While -11.84 isn't as close to -12 as I'd hope, it should be OK.

That being said, Z4 is a readily available 4558 op-amp. If you have access to the parts (and if the output from Z4 doesn't match between cards) this would seem to be a good, easy item to change first. If that does not help, I would look more closely at Z3 and Z5.

Where should I start for not working cards?

In your original posting you had one other voice card that you noted "...both the output from TP 1 and 2 are too low..."

A good starting point would be to trace back the control voltages here too as you did with the card above, looking at the output of Z21 and Z23. If they control voltages are too high/too low, that would explain the frequency error at TP 1 and TP 2. You can then look to see if that's due to the actualy Sample and Hold circuitry or something else.

Channel Motherboard on eBay

Chris Ryan [21030691] · Fri, 5 Dec 2003 22:19:21 -0800

Item number 2579370318, currently US$9.00.

Here are the pictures.

David Clarke [21030085++] · Sat, 06 Dec 2003 10:04:14 -0500

It looks like it closed for $39.00.

I've taken a quick look at some of those items recently listed (the ones which say they've come from an ARP repair centre). While the items would likely be a good source of parts, they probably won't be 100% useable upon receipt.

The I/O board that was previously listed was missing a couple ICs, one of which looked like the 7541 DAC. The motherboard looks to be missing some of the header pins (that the channel boards push down on to) - specifically all the pins that would be used for channel board #3.

That's not to say these may not be good items to pick up - as long as whoever's interested takes a close look at what they're going to get.

I wonder what'll be up for sale next?

David Gowin [21030611] · Mon, 08 Dec 2003 09:13:53 -0500

I have the feeling that the parts came from what I believe was Music Dealer Service, a company in Chicago that bought out a lot of parts when ARP went under. When they were still in business, I purchased some parts and upgrade kits for my Odyssey, all were new, not reconditioned.

David Clarke [21030085++] · Mon, 08 Dec 2003 19:11:57 -0500

CPU board on Ebay

I see that there seems to be a CPU board up for Auction right now (and a third EQ board!?). The CPU board looks brand new. This might be a good opportunity for anybody with an acid eaten board to get a clean replacment ...

Doug Terrebonne [21030114] · Mon, 8 Dec 2003 22:42:31 -0800 (PST)

Re: CPU board on Ebay

Looks like some green battery corrosion if you look closely at the battery holders...

David Clarke [21030085++] · Tue, 09 Dec 2003 19:52:29 -0500

Re: CPU board on Ebay

Do you reckon? I tried to take a closer look (and I can see where you can 'look through' the holder and see the green PWB underneath) but I couldn't see anything bad (it looks cleaner than I couple I have here :-> )

Z4/Overvoltage Protector (Lambda L60V6) Availability

David Clarke [21030085++] · Sat, 06 Dec 2003 10:15:12 -0500

I see that some of the part broker places (like www.usbid.com) do have this Chroma Power Supply part listed (USBid lists 62 being available).

Does anyone (through work, or though a business account) have dealings with the big broker houses? If so, anybody able to find out what the list price is for these items? (it would be good to know, as a couple people now have run into problems with this part).

Attack Times (redux)

David Clarke [21030085++] · Sat, 06 Dec 2003 13:05:38 -0500

See original thread Attack Times (October 2003)

While looking at the question of the attack lag-time a while ago, I became interested in how the Attack and Release settings (from the panel) correspond to honest-to-goodness (clock) time.

I wasn't set up to take perfect plots - but the following picture shows the shape of the the voltage input to the channel VCA when the channel is set to minimum attack, minimum decay.

The following picture represents a more generalized VCA voltage input, with a finite attack, a sustain period, and then a decay/release.

Attack Response

The panel attack settings go from 0 (instant) up to 31 (slow). Measurements for each of these settings are below:

Attack Setting (Panel) Attack Time (milliseconds)
(instant) 36.4 * (note 1)
1 50
2 67
3 78
4 89
5 96
6 111
7 125
8 147
9 176
10 205
11 240
12 288
13 337
14 418
15 508
16 614
17 738
18 880
19 1056
20 1284
21 1648
22 1930
23 2290
24 2730
25 3295
26 3990
27 4760
28 5620
29 7000
30 8840
31 10520

Note 1: The keyboard algorithm chosen affects the initial delay/lag. "instant" was measured as low as 3mS, but using the same program but with a ALL CHAN poly keyboard algorithm selected resulted in a 20-40ms delay to the first audio out.) Regardless, the shape of the plot is the same - but the absolute response (depending on the algorithm) may start a little sooner or later.

Decay Response

The decay settings go from 0 (Instant) up to 30 (slow). It was observed that the relationship between the decay setting and time is once again exponential. Some representative values were tabulated below:

Decay Setting (Panel) Decay Time (milliseconds)
1 39
2 120
3 160
4 210
7 360
9 660
22 6600
30 45000
Release Response

The release settings go from 0 (instant) up to 30 (slow). It was observed that the relationship between the release setting and time is exponential. Some representative values were tabulated below:

Release Setting (Panel) Release Time (milliseconds)
1 36
2 120
22 8600
30 45000

new chroma owner

Olli's troubleshooting posts and their responses are grouped together in this single main thread, as the messages and their responses through the sub-threads cover overlapping issues.

Olli [21010284] · Mon, 8 Dec 2003 22:20:17 +0100

hi there,

i will go to the airport to pick up the chroma i just bought over the phone.

it has apparently some little problems such as key contacts and very low signal on one of the stereo output channels. nothing really worrying aaparently. the foam is stuck to the instrument as usual with rarely used ones.

it seems to have been used in a german studio by joseph zawinul.

hopefully, i will be able to get it running properly without having to bother you guys on the forum.

best greetings

olli

Chris Ryan [21030691] · Mon, 8 Dec 2003 13:32:08 -0800

i will go to the airport to pick up the chroma i just bought over the phone. [...] it seems to have been used in a german studio by joseph zawinul.

Make sure you save the patches! :) If he didn't load a factory set it would be very interesting to hear them, and legally I would guess that you have some rights to them.

Olli [21010284] · Mon, 8 Dec 2003 22:45:31 +0100

hi

excellent idea actually... any suggestions on how to do so? i am so damn new to the instrument :-) i only remember back in 1982, when i tried to understand it respectfully playing some notes in some store in LA... i was 16 by then ;-)
best

Chris Ryan [21030691] · Mon, 8 Dec 2003 14:02:57 -0800

excellent idea actually... any suggestions on how to do so? i am so damn new to the instrument :-)

Do you have a MIDI convertor? If not, you should pick up the Syntech/Chroma Cult/KMX kit from Ken Ypparila [21030229]. Info with MIDI Retrofits.

The next step is getting communications set up. Probably the easiest way to do this is with a sysex app. Here's what to use for the Mac:

SysEx Librarian (Mac OS X)
http://www.snoize.com/SysExLibrarian/

SysEx (System 7 - Mac OS 9.x)
http://members.cox.net/sgrace9/sysex/

See Editors & Librarians: Mac OS X for more information.

I don't know what equivalents there might be for Windows--anyone have some recommendations?

See Editors & Librarians: Windows for updates on this.

By the way, how did you find out this was Zawinul's Chroma? I wonder if he kept his Expander.

Olli [21010284] · Mon, 8 Dec 2003 23:24:14 +0100

it has the EES interface.

i actually don't know if it really was zawinuls'. the seller told me that he played on it. no clue if it is reliable info the SN is 21010284 what can we deduce from that?

Chris Ryan [21030691] · Mon, 8 Dec 2003 14:36:30 -0800

it has the EES interface.

It's probably worth getting the Chroma Cult one, which is used for most current software. I don't think the sysex format would be compatible (though I could be wrong).

the SN is 21010284 what can we deduce from that?

Just that it was produced from the European market.

David Clarke [21030085++] · Mon, 08 Dec 2003 19:07:56 -0500

Olli wrote:

i will go to the airport to pick up the chroma i just bought over the phone.

Congratulations on your purchase (and welcome to the mailing list).

.. hopefully, i will be able to get it running properly without having to bother you guys on the forum.

Please do not feel shy about using this forum - the folks here are genearlly quite nice and do help, whenever possible.

it has the EES interface.

In the short-term, if you just want to save out the parameters, you can use the original tape interface [See Performance Manual: Cassette Interface]. You can either save them to 'tape' by using a tape record, or capture the audio via digital means (for instance, by recording them with a soundcard).

If you can figure out how to do a 'program dump' with the EES interface (by pushing a momentary switch on the back of the box, I think), we may be able to decode the resulting sysex file.

Chris Ryan [21030691] · Mon, 8 Dec 2003 16:49:20 -0800

In the short-term, if you just want to save out the parameters, you can use the original tape interface. You can either save them to 'tape' by using a tape record, or capture the audio via digital means (for instance, by recording them with a soundcard).

Of course. It's been so long since I used the cassette interface, I'd forgotten about it!

Olli [21010284] · Tue, 9 Dec 2003 19:45:50 +0100

new CHROMA

hi

i finally got my chroma today!

as i told you in previous mails, mine was supposed to be really ugly with some defects and as i bought it over the phone, i really was curious if it was really that terrible and if it was complete.

so the good news is that it actually was very dirty and once cleaned up it really looks great. i cleaned every key and removed the foam with a knife and some disolvent. it really looks very good, i am so happy.

it doesn't work 100% though. there is an error on three voicecards and when i hit the keys the intensity of the displays weakens quite noticably and recovers quickly afterwards.

this makes me beleive that it may just be the powersupply. the mono outputs don't work either but there is a beautiful signal coming out of audio output 0.

do any of you have any suggestions how to solve these problems?

thank you in advance

Olli [21010284] · Tue, 9 Dec 2003 21:10:30 +0100

hi

to sum up i have the following problems:

  1. two voices show an error,
  2. there seems to be a tuning problem as the remaining voices are not precicely in tune there seems to be one out of tune.
  3. the mono-outs don't deliver any signal. the 0-3 outs work.
  4. three keys do not respond
  5. voltage seems to drop slightly upon hitting keys as the displays luminosity drops when i hit a key.

any suggestions?

thank you very much in advance

Robert Shanks [21030301] · Tue, 9 Dec 2003 15:23:26 -0500

Re: new CHROMA

so the good news is that it actually was very dirty and once cleaned up it really looks great. i cleaned every key and removed the foam with a knife and some disolvent. it really looks very good, i am so happy.

Hi -

What kind of disolvent did you use? I need to de-foam mine! I finally have room for it again. I miss my Chroma.

Chris Ryan [21030691] · Tue, 9 Dec 2003 12:53:07 -0800

Re: new CHROMA

A couple of us have used Goo Gone. I tried it when my Chroma was "foamed" and it seemed to work all right; however, it would have been a very time-consuming job, not to mention the fumes; and I eventually had CAE Sound do the work (they did a great job).

Olli [21010284] · Tue, 9 Dec 2003 22:14:15 +0100

Re: new CHROMA

actually, it just took me about 2 hrs. its important to rub the foam residuals away with a knife. but don't cut the wood

nachher.jpg

acetone works great!

Olli [21010284] · Tue, 9 Dec 2003 23:39:43 +0100

key problem resolved

thanks to an old post from david clarke [Re: My Chroma is not happy, September 2003] i managed to solve the key prob by just hitting the contacts manually and then they worked....

David Clarke [21030085++] · Tue, 09 Dec 2003 19:35:35 -0500

Olli wrote:

  1. two voices show an error,
  2. there seems to be a tuning problem as the remaining voices are not precicely in tune there seems to be one out of tune.

The two items above may be related.

If at all possible, the first thing to try would be to ensure that the voltages coming from the power supply are OK - and that the DAC offset is adjusted (the procedure to do these are available in the service manual, available on-line).

These items can affect the overall behaviour of the voice cards.

After that, there is the pulse-width adjustment on each of the voice card (again, the procedure to perform the update is noted in the service manual).

Assuming those have been checked (and if a problem is still seen), I'd then suggest that you remove all the voice boards.

Now, add them back in, one at a time, powering on/off in between each addition. As soon you find a board that reports an error, set it aside. Hopefully you'll be able to install 6 of the boards, with only errors being reported for the boards that are physically not installed.

You may indeed have a couple sick (or weak) voice cards.

In the short term you can always run with fewer cards. Everything should work fine - you might just loose a bit of polyphony.

  1. the mono-outs don't deliver any signal. the 0-3 outs work.

The one noteable thing about the mono-outs are that they go through the mixer and tone controls (i.e., the circuit board located just to the left, inside the main panel - where the volume and tone sliders are).

I'd recommend that you check to see if there are any wires missing or disconnected from that block (possibly a connector has come loose in shipping).

Also, the wires just inside the back panel (where the 1/4" jacks connect) can be a bit messy, and sometimes it is easy to have a wire come off. Again, a quick visual inspection looking for things loose or disconnected may be all that you need.

  1. three keys do not respond

(Glad to hear that this has been fixed).

  1. voltage seems to drop slightly upon hitting keys as the displays luminosity drops when i hit a key.

This may not necessarily be a problem (unless you also confirm via measurement that the voltage drops) as the display of even properly working Chromas can be made to go 'dim' or 'blink' if you happen to press down a series of keys all at once. (This has to do with how the display is updated on the keyboard itself).

Good luck in your investigations. Let us know how you make out.

David Clarke [21030085++] · Tue, 09 Dec 2003 19:39:26 -0500

new CHROMA (removing foam)

What kind of disolvent did you use? I need to de-foam mine!

If you don't mind taking a brute force approach, believe it or not gasoline will do the trick (it'll take of most of the underlying varnish too, so a refinish job will likely be in store should that route be taken ...)

Olli [21010284] · Wed, 10 Dec 2003 02:24:01 +0100

Re: new CHROMA (removing foam)

yeah actually it looks much better without the varnish... more natural just as my memorymoog or xpander... you could still wax it...

Olli [21010284] · Wed, 10 Dec 2003 20:59:13 +0100

voice cards

hi

after a PSU adjustment and IO null voltage adjustment (DAC offset i beleive), i have narrowed down the problem.

two cards KO

on one, on channel B, RESO can't be changed and upon powerup it can take any level that it will keep. the same is happening with the VCO: i can't change the waveform and after each reset, it can take either of all available.

i have changed the 4051's. this seems to have eliminated the VCO tracking problem this board also had.

the other board actually sounds fine if you run it on split 31 mode but i have to check again. maybe just a trimmer adjustment prob?

any suggestions what might cause the remaining probs?

DAVID thank you very much for your valuable advise. the main mono outs remain dead evenafter i have resoldered a wire that was not properly fixed.i checked every possible connection but all seems OK. there seems to be a very weak signal though. could it just be a resistor?

thanks again to david and all the list for any tips.

David Clarke [21030085++] · Wed, 10 Dec 2003 19:37:08 -0500

Re: voice cards

the other board actually sounds fine if you run it on split 31 mode but i have to check again. maybe just a trimmer adjustment prob? any suggestions what might cause the remaining probs?

If it generally sounds OK I would suggest to may play a bit with the VCF/resonance to see if the problem becomes audible (i.e., the problem might be 'later' in the voice card, and so might not be immediately heard - especially with a simple patch, like the scratch patch).

the main mono outs remain dead evenafter i have resoldered a wire that was not properly fixed.i checked every possible connection but all seems OK. there seems to be a very weak signal though. could it just be a resistor?

If the signal is available at the mono out (if even weak) I'd start to step through the electronics on page 6-15 of the schematic and see where the signal disappears (there's only two op-amps there, and they're easy to get to - right on the control panel), so it should be a quick step.

Good luck, and congratulations on the good progress so far!

David Clarke [21030085++] · Wed, 10 Dec 2003 19:20:12 -0500

Re: new CHROMA (removing foam)

yeah actually it looks much better without the varnish... you could still wax it...

This is actually what I did on a couple of mine. I stripped all the varnish off, gave it a light sanding, a little bit of stain (to even out the finish), and then a paste wax. I was very pleased with the results (and it is probably the least effort way to go).

Paul Tillotson [21030218] · Wed, 10 Dec 2003 17:30:13 -0800

to sum up i have the following problems:

  1. two voices show an error,
  2. there seems to be a tuning problem as the remaining voices are not precicely in tune there seems to be one out of tune.
  3. the mono-outs don't deliver any signal. the 0-3 outs work.
  4. three keys do not respond
  5. voltage seems to drop slightly upon hitting keys as the displays luminosity drops when i hit a key.

any suggestions?

Error # 5 was present on my fully functioning Chroma back when it was fully functioning.

David Clarke [21030085++] · Wed, 10 Dec 2003 22:39:55 -0500

Error Message Reported

Paul - while the Chroma may have operated 100% normally (i.e., no notes out of tune, etc.) the error message is an indication that one of the voice boards failed the auto-tune, and was automatically removed from the voice-assignment algorithm.

That meant that the Chroma would have been operating as if it only had 7 voice cards installed (instead of the intended 8).

A completely functioning Chroma should be able to boot/come out of a power up without any "Err" indications in the small LED display.

Olli [21010284] · Thu, 11 Dec 2003 12:11:49 +0100

Re: voice cards

hi david (again! :-) )

If the signal is available at the mono out (if even weak) I'd start to step through the electronics on page 6-15 of the schematic and see where the signal disappears (there's only two op-amps there, and they're easy to get to - right on the control panel), so it should be a quick step.

Good luck, and congratulations on the good progress so far!

thank you!

actually, it is only the chinch mono out for the headphone. the studio outs work after i resoldered the wire. even stranger.... hmmm the problem must stem from the source the brown wire connects to. i'll check the opamps. maybe one amplifies the headphone signal.

Olli [21010284] · Thu, 11 Dec 2003 15:08:51 +0100

voicecard contacts

hi there hi david, :-)

instead of working i have passed this morning trying to repair that voiceboard with

  1. max. resonance and
  2. impossibility to change the filter mode.

i have changed the Z27, Z11, Z8 the transistor which is responsible for self oscillation and have checked the soldering points on the VCF chip etc. no result.

then i got the brilliant idea of looking at the contacts P5-8 and discovered that on P7 contact 1 and 8 seem to have disappeard in the little plastic contact box (whatever it is called) could that be the source of the problem? on the other broken DCB, there its just contact 8 broken .... and this one works better...

is this part still available somewhere?

Olli [21010284] · Thu, 11 Dec 2003 22:00:08 +0100

first half time victories and things remaining to be done

hi

problems solved:

  • outputs
  • keyboard
  • DCB calibration with my new SCOPE! YEEEEEEESSSSS!

remaining:

  • 2 DCB's KO.

on both one of the connectors KO. before i replace every single component on the boards, i would like to replace the connectors....

-> question: what are these called (i am novice :-) ) are they still available in electronics shops?

thanks again!

David Clarke [21030085++] · Thu, 11 Dec 2003 20:19:50 -0500

Re: voicecard contacts

then i got the brilliant idea of looking at the contacts P5-8 and discovered that on P7 contact 1 and 8 seem to have disappeard in the little plastic contact box (whatever it is called) could that be the source of the problem? on the other broken DCB, there its just contact 8 broken .... and this one works better... is this part still available somewhere?

Olli - good news:

  1. The contacts you list will certainly affect the abilities of the card (they control over patching/mode selection on the board).
  2. The voice-card connectors are still readily available. The manufacturer is Molex/Waldom and many companies will carry them.

A good on-line source for the parts is Digikey (www.digikey.com). The specific part number you'll want is WM3006-ND. The digikey web page will also list other equivalent part numbers.

Each voice card has 4 of these connectors, and they're about $1US ea. (in small quanitites).

The currently available part is an exact replacement for the originals.

David Clarke [21030085++] · Thu, 11 Dec 2003 20:23:35 -0500

Re: voicecard contacts

David Clarke wrote:

One other quick thought. To prove that the connector is the only problem, you may want to remove a good-connector from one board, and install in the 'bad' location on the other board.

In that way you'll end up with 1 card with two bad connectors instead of 2 bad cards, with 1 bad connector each (so, as least for the short term you can have 7 working voice boards, instead of 6).

David Clarke [21030085++] · Thu, 11 Dec 2003 20:33:51 -0500

headphone output

... actually, it is only the chinch mono out for the headphone. the studio outs work after i resoldered the wire. even stranger.... hmmm the problem must stem from the source the brown wire connects to. i'll check the opamps. maybe one amplifies the headphone signal.

Olli, just to confirm, there aren't actually any head-phone level outputs on the Chroma - all of the 1/4" outputs are actually mono, line-level outputs.

Olli [21010284] · Fri, 12 Dec 2003 09:31:26 +0100

Re: voicecard contacts

hi david,

  1. The contacts you list will certainly affect the abilities of the card (they control over patching/mode selection on the board).
  2. The voice-card connectors are still readily available. The manufacturer is Molex/Waldom and many companies will carry them.

A good on-line source for the parts is Digikey (www.digikey.com). The specific part number you'll want is WM3006-ND. The digikey web page will also list other equivalent part numbers.

Each voice card has 4 of these connectors, and they're about $1US ea. (in small quanitites).

ok excellent. i'll try to find them at a local store. i am really eager to see this error message disappear!

Olli [21010284] · Fri, 12 Dec 2003 09:33:23 +0100

Re: voicecard contacts

One other quick thought. To prove that the connector is the only problem, you may want to remove a good-connector from one board, and install in the 'bad' location on the other board.

In that way you'll end up with 1 card with two bad connectors instead of 2 bad cards, with 1 bad connector each (so, as least for the short term you can have 7 working voice boards, instead of 6).

i have thought about that, but i only have a manual desolder pump. i would need a professional unit to to this or i will burn it. plus, i think if those connectors are tired, i'll better use new ones altogether.

Olli [21010284] · Fri, 12 Dec 2003 09:35:19 +0100

Re: headphone output

Olli, just to confirm, there aren't actually any head-phone level outputs on the Chroma - all of the 1/4" outputs are actually mono, line-level outputs.

don't know what has happenend but all outs work :-) even the high level. but the studio out has more gain.

Olli [21010284] · Fri, 12 Dec 2003 20:14:34 +0100

Re: voicecard contacts

A good on-line source for the parts is Digikey (www.digikey.com). The specific part number you'll want is WM3006-ND. The digikey web page will also list other equivalent part numbers.

many thanks again david,

i have placed and order with digikey. i have ordered 10 pieces. that should suffice under normal circumstances. international shipping is pretty expensive...

Sandro Traversi [21010217] · Sat, 13 Dec 2003 16:14:03 +0100

Re: voicecard contacts

Maybe I'm in late, but I'd advise to check also Europe based traders as

Olli [21010284] · Sun, 14 Dec 2003 03:23:34 +0100

Re: voicecard contacts

hi sandro! hihi, i was too fast. but thanks that will be useful for the next order. i made a quick search but the only ones who had them were digikey the ones david recommended.

Olli [21010284] · Sun, 14 Dec 2003 04:12:33 +0100

Re: voicecard contacts

actually both have them just the reference is different... thanx

Paul Tillotson [21030218] · Sat, 13 Dec 2003 20:52:14 -0800

Re: Error Message Reported

Actually, what I meant was item #5 on their list of troubles, which was, I believe that the display dimmed when they hit the keys at full velocity, but now that you mention on it, my so called fully functioning Chroma did boot up with an error message - error #3 meaning voice card three had failed as usual. But the display did dim when striking the keys hard, anybody else?

David Clarke [21030085++] · Sat, 13 Dec 2003 23:55:50 -0500

Re: Error Message Reported

Paul Tillotson wrote:

...But the display did dim when striking the keys hard, anybody else?

Yep. I do believe this is actually 'normal operation' and has to do with the way the firmware updates the display.

David Clarke [21030085++] · Sun, 14 Dec 2003 10:21:39 -0500

new CHROMA (patches?)

Olli - now that you'd had a chance to at hear a bit of your new Chroma, did you find any patches in the keyboard that were particularly interesting or unusual?

Olli [21010284] · Sun, 14 Dec 2003 19:22:35 +0100

Re: new CHROMA (patches?)

not really, quite standart one or two interesting sounds. i can try to recoup them for you.

Olli [21010284] · Mon, 15 Dec 2003 19:13:15 +0100

yippieh!

the midi interface works. i just had to change the cable! now, i will be able to recoup the sounds on sysx.

Olli [21010284] · Mon, 15 Dec 2003 21:36:00 +0100

midi sysex

hi everybody

(i guess that's just david and chris) :-)

as i told you earlier, everything works, even my EES wiescholek interface i receive midi and the unit transmits midi, too if i can beleive the input channel diode on my OPCODE STUDIO 5 LX which lightens when i strike a key on the chroma.

i then proceeded to save the patches in my unit as a sysex file (3,5 KB) by pushing on the red button of my interface. that looks shorter than all the other sysex files posted on the site.

than i tried to dump different banks to my chroma with the SYEX untility. the data leaves my interface but it doesn't seem to arrive at the chroma. it works fine with my wavestation though.

i see no reaction of the instrument whatsoever. not even an error message. is there anything i have to set up on the unit to enable it to receive midi sysex data?

here is the bank that i saved (or at least the data that SYSEX has saved as coning out of the unit)

(would be interesting to know if other chromas can charge the bank.)

any suggestions?

thank you in advance

Chris Ryan [21030691] · Mon, 15 Dec 2003 12:57:46 -0800

Re: midi sysex

On Dec 15, 2003, at 12:36 PM, Olli wrote:

than i tried to dump different banks to my chroma with the [SYSEX] untility. [...]

Olli, could you supply some more information on this utility, such as author/company Web site? As a Mac user I know what to recommend for that platform, but the question of how to send and receive sysex comes up regularly (yes, there will be a "real" FAQ as part of the next major revision of the site) and I don't know where to point Windows users.

Olli [21010284] · Mon, 15 Dec 2003 22:08:09 +0100

Re: midi sysex

hihi i am mac, too i use sysex 4.8 or so.

Malte Rogacki [21010091] · Mon, 15 Dec 2003 22:15:24 +0100

Re: midi sysex

Here we go.

The EES interface uses a different SysEx format then the Chroma Cult interfaces. Not only does it use its own SysEx ID (EES vs. Fender); it also uses a different encoding scheme for the bytes. The Chroma Cult uses two nibbles for each byte (that's why all the data bytes except the header bytes and the program numbers start with a "0") while the EES interface clearly uses all available seven bits and consequently needs fewer bytes (that's why the dump was shorter).

If I had documentation or a working unit I probably could try to figure out what is going on and how to convert between the two formats (at least in SoundDiver, that is). I recall faintly calling EES years ago to inquire about the format but got no real answer.

Olli [21010284] · Mon, 15 Dec 2003 22:51:31 +0100

Re: midi sysex

hi malte,

maybe a good start would be that i try to use the cassette interface to dump a known bank to my chroma i.e. the factory bank 1.

then, i export it throught sysex and send you the file. then you could see what happens as you know the sounds and can compare the two sysex-files!

what do you think?

Malte Rogacki [21010091] · Mon, 15 Dec 2003 23:04:59 +0100

Re: midi sysex

That's fine with me. I don't have a Chroma myself at the moment but maybe I can figure something out.

Olli [21010284] · Mon, 15 Dec 2003 23:22:15 +0100

midi sysex - EES Decode

hi malte,

that sounds cool.

trouble is, that i don't have an audio file of a bank available in sysex on the site.... and as a macuser, i can't transform a bank into audio with the tools....

can anybody provide an audio file of, say, "factory bank 1" to enable malte to see if we can convert the sysex-files?

thank you

Chris Ryan [21030691] · Mon, 15 Dec 2003 15:00:58 -0800

Re: midi sysex

I posted Factory Set 1 as a test a couple of years ago: [see Patch Downloads].

David Clarke [21030085++] · Mon, 15 Dec 2003 18:40:59 -0500

Re: midi sysex

maybe a good start would be that i try to use the cassette interface to dump a known bank to my chroma i.e. the factory bank 1. then, i export it throught sysex and send you the file. then you could see what happens as you know the sounds and can compare the two sysex-files! what do you think?

Olli - if you don't make out OK with the factory bank, we can probably figure out the sysex file format as long as we have a good bank as a reference.

So, if you were to pick a particular patch, and then then step through the 95 or so parameters (channel A and Channel B) for that patch, and write them down that may be enough info (really, there's only going to be so many 'easy' ways to encode the data stream).

David Clarke [21030085++] · Mon, 15 Dec 2003 19:41:46 -0500

Re: Chroma: midi sysex - EES Decode

I've taken a quick look at the sysex dump provided by Olli.

The general format seems to be:

  • F0 {sysex header}
  • 63
  • 43
  • and then Qty 50 programs of 69 bytes each, where the first byte is the program number
  • F7 {sysex footer}

A 68-byte payload per program is probably about right.

Inside the Chroma, each program takes up 59 8-bit bytes. In that store, some 24 bits are unused.

So that leaves (59 X 8) - 24 = 448 bits of real program data.

The sysex payload can only be 7-bit data (by definition), so, assuming perfect packing that'd be 64 bytes.

I'm guessing that the other 4 bytes are needed to account for the fact that you don't want parameters to straddle more than one byte.

Given the notes above, I'm hopeful that we'll find a direct 1:1 correlation between the data and the fields in the EES data (and if so, we can create an easy little KMX<->EES sysex converter.)

Olli, it might be a little bit of work on your end, but the easiest way to decode the format is to:

  • Do a SYSEX Dump
  • Modify only 1 parameter (for instance in prog 1)
  • Do another SYSEX dump
  • identify which byte/data position changed in the SYSEX dump.
  • repeat

At that end of this, you'll be able to map the parameters to positions in the prog 1 dump.

Olli [21010284] · Tue, 16 Dec 2003 02:11:17 +0100

Re: midi sysex - EES Decode

hi david,

you guys are incredible! :-) (made with sound diver, SYSEX 4.8 didn't capture the dump for some reason...)

i have made a EES sysex copy of factory bank 1 (above) that way, we will be able to compare one-one the two formats.

maybe that is an easier way.

you think you can figure that out with the two files, malte?

if not, i'll have to do what dave suggests and do 50 SEX's...

David Clarke [21030085++] · Mon, 15 Dec 2003 23:27:51 -0500

Re: midi sysex - EES Decode

i have made a EES sysex copy of factory bank 1 (above)

Olli - what did you use as the source of this load? Was it the link that Chris Ryan provided? [Factory Set 5 audio file--see Patch Downloads]

If that's the case, then I believe we should be comparing the EES dump vs. the Factory Bank 5 sysex (as the text on [obsolete page] indicates that the patch dump is FS5).

If I assume that the output is really for FS5, then the data does seem to make a bit of sense. It looks like the stored format tries to generally follow the Chroma Parameter List in the Computer Interface manual - but where it 'runs out of bits' things get a bit messy-er.

Chris Ryan [21030691] · Mon, 15 Dec 2003 23:24:26 -0800

Re: midi sysex = EES Decode

Yes, sorry--my mistake earlier; the audio file is Factory Set 5. I hadn't looked at the page closely enough and it has been a few years since I posted it (it was meant as a test to see if the audio format would work--it's not really linked from anywhere).

Malte Rogacki [21010091] · Tue, 16 Dec 2003 13:33:09 +0100

Re: midi sysex - EES Decode

If I assume that the output is really for FS5, then the data does seem to make a bit of sense. It looks like the stored format tries to generally follow the Chroma Parameter List in the Computer Interface manual - but where it 'runs out of bits' things get a bit messy-er.

I must say that after a first glance I cannot make sense out of the formatting (but maybe I'll have to look closer). A few starting points: Good places to look for are IMHO the modulation amounts. Those go from -64 to 63 if I recall correctly and consequently should use all 7 available bits in the dump. Now; the first program has two pitch modulation amounts of -28. However I cannot find at first glance two amounts that seem to correspond to that.

Olli [21010284] · Tue, 16 Dec 2003 14:16:33 +0100

Re: midi sysex - EES Decode

hi

anyone konws if the fader buttons are still available somewhere?

David Clarke [21030085++] · Tue, 16 Dec 2003 17:53:58 -0500

Re: midi sysex - EES Decode(d)

I tried to start with that exact same thinking - and hit the same brick wall.

I took a few minutes at lunch today (with a set of fresh eyes) and was able to figure it out.

It's not necessarily encoded the way I would have done it - but once you see it, it is quite straight forward (and easy to handle).

The midi payload has to be 7-bit data. The data as stored in the Chroma is 8-bit data.

The way that they handled the 7-bit/8-bit disparity was to bit shift everything to the right (leaving the top bit empty). They took the "bits that would have fallen off the end", and collected them in its own 7-bit data byte.

So what we have is actually something like: 

Byte 0   0 {program number}
Byte 1   0 a7 a6 a5 a4 a3 a2 a1
Byte 2   0 b7 b6 b5 b4 b3 b2 b1
Byte 3   0 c7 c6 c5 c4 c3 c2 c1
Byte 4   0 d7 d6 d5 d4 d3 d2 d1
Byte 5   0 e7 e6 e5 e4 e3 e2 e1
Byte 6   0 f7 f6 f5 f4 f3 f2 f1
Byte 7   0 g7 g6 g5 g4 g3 g2 g1
Byte 8   0 a0 b0 c0 d0 e0 f0 g0
...
Byte 9   0 h7 h6 h5 h4 h3 h2 h1
...
Byte 65  0 x7 x6 x5 x4 x3 x2 x1
Byte 66  0 y7 y6 y5 y4 y3 y2 y1
Byte 67  0 z7 z6 z5 z4 z3 z2 z1
Byte 68  0 x0 y0 z0 ?  ?  ?  ?

Where (a7 a6 a5 a4 a3 a2 a1 a0) would represent the 8-bits of a byte of Chroma program data.

The individual lines correspond 1:1 to the memory structure for programs in the Chroma itself.

As the translation is actually straightforward, I was able to create both an EES -> Chroma Cult converter and a Chroma Cult -> EES converter. I should be able to post those items later tonight.

David Clarke [21030085++] · Tue, 16 Dec 2003 17:59:26 -0500

fader buttons?

anyone konws if the fader buttons are still available somewhere?

Olli - are you looking for the sliders themselves, or the little black caps?

Olli [21010284] · Wed, 17 Dec 2003 10:17:29 +0100

Re: fader buttons?

hi david

just the little caps. i have caps on all of the sliders but the little hole for the slider in some of the caps is a little too big so that they tend to be loose.

and i would like the instrument to be perfect after all these efforts :-)

but it may be interesting to know a source for the sliders themselves, too

Olli [21010284] · Wed, 17 Dec 2003 00:17:06 +0100

Re: midi sysex - EES Decode(d)

wow!

david, competency and efficiency! once again: you are a master. :-)

As the translation is actually straightforward, I was able to create both an EES -> Chroma Cult converter and a Chroma Cult -> EES converter. I should be able to post those items later tonight.

analysis plus solution! you are faster than EES in figuring out their own format.

how can i thank you? hihi, maybe by sending you 10 of the 20 WM3006-ND i just ordered at digikey? ;-)

folks! honors to DAVIIIIIIIIIIID! applause....

Malte Rogacki [21010091] · Wed, 17 Dec 2003 00:26:16 +0100

Re: midi sysex - EES Decode(d)

The way that they handled the 7-bit/8-bit disparity was to bit shift everything to the right (leaving the top bit empty). They took the "bits that would have fallen off the end", and collected them in its own 7-bit data byte.

So what we have is actually something like: [...]

I was experimenting along the same lines earlier today but without much success. (Whiny voice) Why is it always that each manufacturer has to create it's own transmission format?

Right "out of the box" SoundDiver cannot handle this one. SoundDiver *does* handle two similar formats that transmit the *highest* bit first or last (for Korg and Dr. Boehm devices). But I don't know of any other device that uses this particular encoding.

David Clarke [21030085++] · Tue, 16 Dec 2003 22:28:16 -0500

connectors for voice cards

Olli wrote:

how can i thank you? hihi, maybe by sending you 10 of the 20 WM3006-ND i just ordered at digikey? ;-)

Olli - I think you better hold on the connectors, just in case :->

(I'm happy to help when/if I can).

With specific note to the connector part - I think there is a reference in the Chroma archives (maybe in the Analog Heaven archives?) that talks about the manufacturer's predicted 'insertion life' of these. If my memory serves me, I think it was some very small number (maybe a couple hundred?)

David Clarke [21030085++] · Tue, 16 Dec 2003 22:20:47 -0500

Re: midi sysex - EES Decode(d)

Malte Rogacki wrote:

I was experimenting along the same lines earlier today but without much success. (Whiny voice) Why is it always that each manufacturer has to create it's own transmission format?

I'm not really sure why they would have done it this way either. If you have to receive multiple bytes to do the decode anyway, it probably would have been just as easy to bit-pack everything ... :-<

And really - considering the small size of the files anyway, they could have gone the route of the KMX/Syntech interface and just split everything into nibbles ...

(Then again, considering my coding style, I certainly can't criticize :->)

Right "out of the box" SoundDiver cannot handle this one. SoundDiver *does* handle two similar formats that transmit the *highest* bit first or last (for Korg and Dr. Boehm devices). But I don't know of any other device that uses this particular encoding.

Is there any sort of 'scripting' available in SoundDiver that would let you 'roll your own', or pre-/post-process the data?

I've attached the .c source (and DOS Executables) for the two programs - syx2ees and ees2syx. The comments at the beginning of ees2syx.c [C source file, 8K] re-iterate the general info sent to the list (about the EES data format).

I tried to use the FS5 data to validate the conversion back and forth (and the binary compares on that data seems OK) - but that's a small sample-set so there is still a possibility of error. Everyone please let me know if there are any gross errors.

Chris R. - I guess these items could eventually go up on the Patch Conversion Tools page. [Done.]

Olli [21010284] · Wed, 17 Dec 2003 10:44:49 +0100

Re: midi sysex - EES Decode(d)

well .c source, i guess that is programming language C? :-)

i'll get a PC in a couple of weeks. in the meantime, can i get this little marvel to run on my OS X mac?

as you can see, i am not really into programming... ;-)

Malte Rogacki [21010091] · Wed, 17 Dec 2003 13:01:48 +0100

Re: midi sysex - EES Decode(d)

I'm not really sure why they would have done it this way either. If you have to receive multiple bytes to do the decode anyway, it probably would have been just as easy to bit-pack everything ... :-<

And really - considering the small size of the files anyway, they could have gone the route of the KMX/Syntech interface and just split everything into nibbles ...

I just got a call back from EES and they confirmed the transmission encoding.

Apart from that I also found out that the EES interface in fact allows dump requests and single dumps as well; but they couldn't get me the code. However it seems that the Atari Chroma editor by Oliver Kirschning used those codes. So somebody with that editor and a second computer could probably figure out which requests are sent. I'm trying to find out more and possibly obtain documentation for the interface.

Olli [21010284] · Wed, 17 Dec 2003 13:10:32 +0100

Re: midi sysex - EES Decode(d)

However it seems that the Atari Chroma editor by Oliver Kirschning used those codes.

that is right malte.

Olli [21010284] · Wed, 17 Dec 2003 15:31:38 +0100

Re: midi sysex - EES Decode(d)

hi david,

i have received my PC today and have tried to use the SYx2EES utility from the black DOS window in my XP system. hmmmmm as i do not know much about PC's i didn't manage.

i did type SYX2EES c:\chromacultsysex\chroma cult 01.syx (that is the place and name of the file i wanted to convert) and the system said that ESX2EES is an invalid command...

okok please don't laugh :-) i know, i am clueless argh!

Chris Ryan [21030691] · Wed, 17 Dec 2003 08:17:05 -0800

Re: midi sysex - EES Decode(d)

On Dec 17, 2003, at 1:44 AM, Olli wrote:

well .c source, i guess that is programming language C? :-)

It is.

i'll get a PC in a couple of weeks. in the meantime, can i get this little marvel to run on my OS X mac?

I'll see if I can put something together.

David Clarke [21030085++] · Wed, 17 Dec 2003 19:17:04 -0500

SYX2EES

i have received my PC today and have tried to use the SYx2EES utility from the black DOS window in my XP system. hmmmmm as i do not know much about PC's i didn't manage. i did type SYX2EES c:\chromacultsysex\chroma cult 01.syx (that is the place and name of the file i wanted to convert) and the system said that ESX2EES is an invalid command...

Olli - save the syx2ees.exe file to a local directory so if you type 'dir' at the black DOS window prompt you should see the file listed.

Now, just by way of a test, type the file name without any parameters, it should respond similar to the line below:

H:\music\Rhodes\chroma\UTIL>SYX2EES.exe

Syntax: SYX2EES {filename.syx} where filename is a 50 program KMX sysex file

If you can see this message, it says the executable is visible and arrived OK.

Now you should be able to attempt the conversion you wanted. If it complains, try moving the .syx file to the current directory - and possibly shortening the file name to the older 8+3 filename format (e.g., factory1.syx).

Let us know how you make out.

Olli [21010284] · Fri, 19 Dec 2003 00:25:03 +0100

SYX2EES works!

hi david

your 150 manyear software tool development marathon is a succes! i suppose debugging 1 terabyte of assembler code was a major challenge? ;-)

it was worth the efforts! i have coverted all the soundbanks on the site! i'll post them to chris for publication on the site.

YES!

quite interesting sounds, imho.

thank you again david, very cool tool.

best wishes

olli

The EES <-> Syntech utilities are available, along with source code, from the Patch Conversion Tools page.

Linear vs. Switching

Wayne Griffin [16330111] · Mon, 8 Dec 2003 21:56:45 -0500

Dear List,

I was reading some old threads about Chroma power supply issues and this brought me to wonder about something a friend of mine who is very Tesla-like said. I was curious if yall think that in terms of noise- are there any advantages to the big ole nasty linear power supplies that are in instruments of this vintage?

Rich Hilleman [21030351+] · Mon, 8 Dec 2003 22:38:25 EST

Something to consider is that switching PS's introduce some clocking noise. In this case, it is small potato's by comparision to the noise produced by the digital components on the rest of the system. Most of the time, the clocking noise will overwhelm the Switching noise, but some of the quicker LFO settings might be impacted.

On the other hand, the Switchers are a lot more reliable and a lot easier to replace.

My tech is old school and believes that the stock PS just requires bigger caps. One of my two Chroma's keys has had the PS upgrade and the reliabilty difference is noticable (along with a real impact on the noise floor). My other Keyboard and my Expander haven't gotten the treatment yet, and I regret it. When I get the CS80 out of him (no one jumps on those guys) the expander will go back in.

David Clarke [21030085++] · Wed, 10 Dec 2003 19:41:42 -0500

I was reading some old threads about Chroma power supply issues and this brought me to wonder about something a friend of mine who is very Tesla-like said. I was curious if yall think that in terms of noise- are there any advantages to the big ole nasty linear power supplies that are in instruments of this vintage?

While I have chosen to keep the original linear supplies in the keyboards I have here, I have to admit they themselves are noisy - albeit mechanically noisy (presumably magnetostrictive transformer noise ...)

In addition to the tapper giving a positive audible indication that a button has been pressed, you can tell the Chroma has been powered up (without looking) just by listening for the hum/buzz of the transformer).

EQ Board(s) on Ebay - CEM3360

David Clarke [21030085++] · Tue, 09 Dec 2003 19:58:17 -0500

There have been a couple Chroma EQ boards listed recently on Ebay. Just by way of a reminder, each EQ board will actually have Qty 2. CEM3360 installed in them.

The last two boards sold for $21 and $32 respectively. That's cheaper than the price of a single CEM3360, were you to buy it separately.

service manual

Olli [21010284] · Wed, 10 Dec 2003 02:43:40 +0100

hi there

i have just transformed the service manual in one handy PDF file if you want to post it on the site... its just 1,9 MB instead of 2,8 for the TIFF collection...

Sandro Traversi [21010217] · Wed, 10 Dec 2003 19:22:45 +0100

ooh Olli ...

Many thanks !

Chris Ryan [21030691] · Wed, 10 Dec 2003 10:45:50 -0800

If you e-mail it to me directly I'll post it to the site.

See Manuals: Service Manual.

Olli [21010284] · Wed, 10 Dec 2003 22:21:14 +0100

sorry ...

pages 6/ 3-4-14-16-20 are lacking. if anybody has them... plese send them i'll put them in the PDF

Olli [21010284] · Wed, 10 Dec 2003 22:19:12 +0100

hi

i just noticed that the pages 14/16/20 are lacking does anybody have them? i'll insert them in the manual PDF

David Clarke [21030085++] · Wed, 10 Dec 2003 19:26:12 -0500

re: sorry ...

(these are of limited use as they're hard to make out at the best of times)

These were posted with the hypertext version of the Service Manual in 2006.

I can probably scan these from my hardcopy (if needed).

6-14 and 6-20 are actually blank pages in the original service manual, so you don't have to worry too much about those.

Olli [21010284] · Thu, 11 Dec 2003 12:07:23 +0100

Re: sorry ...

hi david!

I can probably scan these from my hardcopy (if needed).

that would be great! i'll put everything in the PDF. btw. is there a PCB layout picture of the voice cards? there is no such file in the TIFFs.

plus, the scan of the voicecard schematics is not very lisible because of the low resolution. if you kindly scan the lacking pages, it would be great if you could scan that one again, too.

thanks again david

Olli [21010284] · Thu, 11 Dec 2003 19:15:46 +0100

hi there

i have found a funny thing on the remaining DCBs.... if there is LFO filtermod with sawtooth some cards seem to use ascending and some a descending ramp... hmmmm.

David Clarke [21030085++] · Thu, 11 Dec 2003 20:38:18 -0500

Poor Service Manual Scans

btw. is there a PCB layout picture of the voice cards? there is no such file in the TIFFs.

Yes - it should be on the top-half of page 6-11.

plus, the scan of the voicecard schematics is not very lisible because of the low resolution. if you kindly scan the lacking pages, it would be great if you could scan that one again, too.

If you'd like to tell me which scans are poor I can re-do them, put them on a CD-ROM and send them to you. You can then adjust the resolution (as needed) for the PDF and submit it to the site.

If you'd like to do this, just let me know which items should be rescanned (and what mailing address you'd like them sent to) and I'll take care of it here.

Seeking flex connectors (from CPU board)

Christopher Now · Mon, 15 Dec 2003 17:14:43 -0500

Hi -

I could badly use the 2 flexible ribbon connectors that connect the Chroma CPU to the I/O board. Before I switch to a different style cable & connector, I thought I'd ping the group.

If you have an extra pair of these, please email me with your asking price.

Thank you

David Clarke [21030085++] · Mon, 15 Dec 2003 18:57:43 -0500

You can still get the exact same style of cable. You can even choose the length you'd like.

Digikey (www.digikey.com) has these (I'm sure other places will too). The part itself is from AMP/Tyco.

The Digikey P/N for a representive cable is:

a9aat-1503f-nd

This specific one is 3" long, and doesn't have the black plastic shroud - but it will work just the same. The 2" version is probably a slightly better fit.

Christopher Now · Mon, 15 Dec 2003 20:04:42 -0500

Thanks for the info David! Have you ever used this replacement part? I'm curious to know if the lack of plastic header shroud will result in the cables coming unplugged.

Olli [21010284] · Tue, 16 Dec 2003 02:12:24 +0100

david you are impressive!

do you know all the chroma references on digikey by heart? :-)

my devotion....

best

David Clarke [21030085++] · Mon, 15 Dec 2003 20:17:49 -0500

Thanks for the info David! Have you ever used this replacement part? I'm curious to know if the lack of plastic header shroud will result in the cables coming unplugged.

I have used the shroud-less cable and have not had a problem. The cable itself is light, and so the fricton of the pins in the connector seems more than ample to keep it in place.

The missing shroud does mean you have to pay a little bit more attention when inserting the cable into the I/O board (to make sure all the pins are started in their holes).

That being said, if you're really keen on having the shroud I'd bet that a little poking around for similar part numbers at Digikey/Tyco may find an EXACT replacement.

Here is a quick pic of what the cable/connector looks like (uninstalled).

Christopher Now · Mon, 15 Dec 2003 20:45:22 -0500

David -

Thanks again for the info and for sharing your experiences and obervations. It looks as though the part will be fine without the shroud - my main concern is in NOT having to use a different style of cable/connector as that will prevent easy board swapping.

My current project CPU board is the first I've ever come across that not only had pcb acid damage, but also acid-eaten flex cables - they literally have holes in them that you can see through. It sounds as if you've also rebuilt a few CPU boards...

David Clarke [21030085++] · Tue, 16 Dec 2003 17:57:43 -0500

Eaten flex connectors

I've seen a couple of these now - strangely enough, both on the CPU boards from Expanders.

I think what happens is that as the batteries leak, they drip down on to the bottom of the Expander chassis itself. Because of the way the panel gets installed, the flex connector rubs the chassis/wooden bottom - where it can effectively 'sit' in the acid.

new registration

Dan Jenkins [21030639] · Tue, 16 Dec 2003 10:42:52 -0800

Hello:

I am the original owner of Chroma SN Y21030639. I purchased it at Charles Music, in Glendale Claif., date unknown. The EPROMS were upgraded to REV. 14 about 2 months later, and a Syntech interface box installed at that time. It eventually became the master keyboard running a Roland D10, A Yamaha TX81Z, a Yamaha WX7 unit and a few other modules I can't recall. The flight case, last time I looked was still in good condition. Sadly, I haven't played the Chroma for several years. This hopefully, will change soon. I am pleased that a site is available for me to interface with my fellow Chromies.

Olli [21010284] · Tue, 16 Dec 2003 20:07:31 +0100

hi welcome dan.

i recently joined the list after having bought a chroma with EES interface which i am currently restoring with the help of some very nice group-members.

have fun.

opamps

Olli [21010284] · Wed, 17 Dec 2003 00:27:18 +0100

hi

i was just wondering if any of you ever has tried to replace the audio opamps with newer and better units from say analog devices to improve the sound.

this has been done successfully on quite some ARP2600s.

vocal sounds

Olli [21010284] · Mon, 22 Dec 2003 01:34:20 +0100

hi there,

one little quick question. i am composing some little stuff for a chroma review that i will publish on a site i am the coauthor of.

i have heard the chroma is great for vocal sounds i love synth vocals.

do any of you have some interesting vocal patches i could use for the review?

thank you

Chris Ryan [21030691] · Sun, 21 Dec 2003 17:45:21 -0800

one little quick question. i am composing some little stuff for a chroma review that i will publish on a site i am the coauthor of.

Be sure to send us the URL when it's up! I'll link to it from the site.

See Reviews for the latest URL.

Olli [21010284] · Tue, 30 Dec 2003 01:41:22 +0100

hi guys

i am still looking for VOCAL sounds. pleaaaaase :-)

David Clarke [21030085++] · Mon, 29 Dec 2003 20:29:56 -0500

Olli - there are a few "Ahh" and "OooEeee" sounds (as part of the Factory sets), but other than that I don't think I've ever heard of any good choral type vocal sounds from the Chroma.

Chroma physical footprint

Wayne Griffin [16330111] · Mon, 29 Dec 2003 12:42:49 -0500

I am trying to make a place to stash my Chroma when it arrives. (Yes, Christmas Money and yes antici------pation)

If someone out there would be kind enough to reach for their tape measure and tell me-

What is the *exact* length X width X height of the Chroma?

Cheers all and happy new year.

Olli [21010284] · Mon, 29 Dec 2003 18:56:21 +0100

1m05* 60cm welcome to the club! i am sure, you will love it

Wayne Griffin [16330111] · Mon, 29 Dec 2003 19:17:20 -0500

Chroma, THE Luxury Item

I would be delighted to hear from the whole list just how you all go about accommodating your Chromas... What sorts of stands are you using? Are you employing it for master control? Anyone hook the tapper circuit up to a mild electric shock :) ?

Dan Jenkins [21030639] · Mon, 29 Dec 2003 16:29:13 -0800

Re: Chroma, THE Luxury Item

well Wayne.. I built my stand out of PVC piping... has held that chroma steady for nigh on 10 years and yes I used it for my main keyboard. Sorry this is a short letter as I am at work.. DanJ

Olli [21010284] · Tue, 30 Dec 2003 01:39:22 +0100

Re: Chroma, THE Luxury Item

acoomodating it i the living room where my collection takes more and more space.... my wife LOVES it :-) grrrr. i have it on a X stand with a preamp and the EES interface on top of it

Rich Hilleman [21030351+] · Mon, 29 Dec 2003 20:21:12 EST

Re: Chroma, THE Luxury Item

I use the Quick Lok WS540 for my Chroma/Expander combo. I have one each for my much heavier CS80, Wave and another for my Synclavier Keyboard. They are bulletproof and they don't interfer with my legs the way a x stand does.

They also have the Chris Ryan Seal of Approval.......

David Clarke [21030085++] · Mon, 29 Dec 2003 20:28:27 -0500

Re: Chroma, THE Luxury Item

I would be delighted to hear from the whole list just how you all go about accommodating your Chromas... What sorts of stands are you using?

One Chroma is on a Quik Lok "X" style stand. That has served well for 10 or so years. Another is sitting atop a hardwood desk (no tipping worries there) :->

By far, the Chroma is the keyboard I have to consider the most seriously whenever I think about moving things around (there are only so many places that it will physically fit).

Are you employing it for master control?

Mostly (however, the keyboards here get routed through a MIDI switcher, so other keyboards are sometimes used as the master controller too.)

Chris Ryan [21030691] · Mon, 29 Dec 2003 18:36:36 -0800

Re: Chroma, THE Luxury Item

I would be delighted to hear from the whole list just how you all go about accommodating your Chromas... What sorts of stands are you using?

My Chroma is sitting on a really solid Roland stand. Couldn't find it on a quick Web search. It has four legs and folds up--not an "X" style stand. Best stand I ever had: very stable, piano height.

Are you employing it for master control?

No--I have a KX88 (for which I also have the stand mentioned above).

Don Tillman · 30 Dec 2003 02:03:56 -0800

Re: Chroma, THE Luxury Item

I would be delighted to hear from the whole list just how you all go about accommodating your Chromas... What sorts of stands are you using?

Quik-Lok WS-550. It works really well.

Are you employing it for master control?

Nope; I don't play musical instruments by remote control.