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ChromaTalk Archives: May 2008

Service Policy Guide

Chris Ryan [21030691] · Thu, 01 May 2008 07:37:34 -0700

New on the site this month is Fender's Service Policy Guide for the Chroma. Thanks to Steve Grom [21030502+] of Fender for this information.

Voice Board on eBay

Chris Ryan [21030691] · Thu, 01 May 2008 17:47:58 -0700

Item #110248995474, starting bid US$15, no bids yet, ends May 8. From the description: "I recieved this extra Voice Board when I purchased my Chroma a couple years ago. This board does not tune in my synthesizer, so it is being sold as not working, though I am sure it is probably an easy fix for someone who knows how to test and fix them."

A couple of the pictures from the auction:

Richard Willoughby [21030348] · Thu, 01 May 2008 19:53:57 -0700

That'd be one of mine. :)

Paul Hackett-Evans [21010094] · Fri, 02 May 2008 12:03:29 +0100

Does this mean that you have more Chroma boards and parts that you're selling, Richard?

Why does your listing say only post to US? Is there a problem with you sending overseas?

Richard Willoughby [21030348] · Fri, 02 May 2008 04:17:59 -0700

Just a choice, that's all.......

I do have another one here I'm coveting until the current auction ends......I'm not sure I'm going to auction that one though.....we'll see.

Matrix [21030220] · Thu, 08 May 2008 21:28:33 -0700

Rhodes Chroma Voice Board

Item #110250901697

This is not mine. Anyone who goes to my site knows I put up auction posts. I just saw this one in my nightly scrub. I figured I'd send it to the list vs. putting up a post. There's a BIN on it. I'm interested in the images so I will hold off on putting up a post until it sells or tomorrow, whichever comes first.

See post Rhodes Chroma Voice Board on Matrix's blog.

Richard Willoughby [21030348] · Fri, 09 May 2008 13:08:15 -0700

Re: Rhodes Chroma Voice Board

That's my last extra voice board I'm auctioning off, as non-working. Feel free to post the pics if you like.

Pictures:

Chroma discography?

Jesper Ödemark [21010135] · Fri, 02 May 2008 09:50:17 +0200

Hi list!

I played a couple of vinyl singles last night and enjoy reading gear lists on sleeves etc. On one of last nights' spins my eyes caught the word "Chroma" on the back of a fairly unknown single from 1983. The band was called English Evenings and the single "English Evenings/What's the Matter with Helen?". The musician playing the Chroma is Graham Lee and the single is produced by Phil Harding.

Searching the Chroma site I see it's 21010120 that I heard...

Have any dedicated Chroma-user ever thought of a Chroma discography?

Chris Ryan [21030691] · Fri, 02 May 2008 06:57:25 -0700

Have any dedicated Chroma-user ever thought of a Chroma discography?

Yes.

Will add English Evenings.

Jesper Ödemark [21010135] · Fri, 02 May 2008 19:27:46 +0200

Great then - I'll keep my eyes opened. I have 6000+ records in my collection and 4000+ in the shop. I bet there is more to be found. :D

EE made a bunch of singles and since Graham mentioned in the registry that he used it a lot I guess you'll only mention the band then?

Syntech Interface on eBay

Chris Ryan [21030691] · Sun, 04 May 2008 08:18:58 -0700

Item #290227656162, "Buy It Now" price of US$449, ends May 13. From the description: "The unit is 100% functional and aside from needing a bit of a cleaning it is in decent cosmetic shape. I will also include a printed copy of the manual. Stay tuned for the actual Chroma!!"

Just a reminder that Ken Ypparila still has a few of these left for US $100, and the full CPU Plus (with many more capabilities) is US$319.

Picture from the auction:

Chris Ryan [21030691] · Tue, 13 May 2008 18:36:59 -0700

This has been re-listed as item #290230277114 with a price of US$399, ending May 23.

CC+ with Midi installed

Richard Willoughby [21030348] · Wed, 07 May 2008 19:55:01 -0700

For the record, I installed Chroma # 21030348 with the CC+ board w/Midi today, and everything works great. Many thanks goes out to David and Sandro. !!!

CC+ question on display

Riccardo Grotto [21010249+] · Thu, 08 May 2008 09:43:10 -0700

This about an expander equipped with CC+ and the new SPSU.

Connected only with midi in to a master keyboard (korg oasys), it received MIDI datas and produce sound correctly (with after touch too).

It also responds to prog change (both with numeric keyboard or with program up command). It does that correctly (the sound is relative to the selected program) but the display does not change the program number.

Is this normal?

David Clarke [21030085++] · Sat, 10 May 2008 15:36:36 -0400

... This about an expander equipped with CC+ and the new SPSU. ... It also responds to prog change (both with numeric keyboard or with program up command). It does that correctly (the sound is relative to the selected program) but the display does not change the program number. Is this normal?

Yes - in most modes, this is expected operation when the Chroma/Expander is being operated remotely (via the CC+ and other interfaces like the KMX/Syntech interface.)

When the Chroma/Expander is running in poly (non-Omni) mode, then it is possible for it to be playing up to 8 different 'instruments', all with their own different programs. In that mode, there would be no way to (easily) show all 8 programs which are active - and so the front panel only reflects the program that has been selected by using the front panel.

That having been said, if the MIDI interface is configured so that it knows that there's only one possible program affecting its playing - then the front panel will reflect the program changes.

Specifically - if the interface is set to run in Omni mode (or 'Play' mode, for the CC+) then only one channel/instrument is active. (see Configuration Interface & MIDI Support, P2).

In that mode, the front panel should reflect the currently selected program (as well as show the LED/selection settings for that specific program).

SPSU Install questions

Frank Hettlich · Thu, 08 May 2008 19:39:35 +0200

Hi Luca,

with all this talk about the shortcomings of the "old" SPSU that I bought a few weeks ago I am a little bit confused...

What exactly has to be modified on the "old" SPSU when/after installing it?

I want to go to my technician in the near future to let him install this kit in one of my Chromas. Hopefully I will get rid of "humming noise" and "error 2" displaying when powering on the machine...

Thanks a lot in advance

Jesper Ödemark [21010135] · Fri, 09 May 2008 07:45:21 +0200

Frank Hettlich skrev:

with all this talk about the shortcomings of the "old" SPSU that I bought a few weeks ago I am a little bit confused... What exactly has to be modified on the "old" SPSU when/after installing it?

Nothing really. Unplugging it is the only messy thing involved.

I want to go to my technician in the near future to let him install this kit in one of my Chromas. Hopefully I will get rid of "humming noise" and "error 2" displaying when powering on the machine...

Probably - it sure helped me. :D (And Luca, the components have arrived. I haven't had time installing them though...)

Thanks a lot in advance

Good luck Frank!

Luca Sasdelli [21010226] · Fri, 09 May 2008 11:07:36 +0200

Hi Frank and all,

The only issue concerning the new SPSU kit is the reset timing, that on some machines (original CPU?) fails and causes the sustain pedal to work the wrong way round; a soft reset (SET SPLIT 50) cures it.

Should this appear, please try to increase the capacity of the tantalum capacitor close to the Reset button, by soldering an extra 10uF tantalum cap in parallel to the existing one, solder side of PCB (underneath); pay attention to polarity: the plus (+) lead should be towards board inner, exactly as the other cap.

Åke Danielson [21010068] · Fri, 09 May 2008 12:35:11 +0200

Hi Luca,

I have the new CPU so that can not be the problem.

loading patches via midi

Jesper Ödemark [21010135] · Sun, 11 May 2008 08:02:19 +0200

Hi list!

I ran across one of these cheap USB-devices on Ebay [item #110250339140] and wonder if it might be useful to load patches to the Chroma (for example). I'm not planning anything fancy, but as it is now I have a crappy old PC with windows 95 on a shelf just for updating studio gear. If that can be changed to one of this little gadgets it'll save space.

Any input appreciated.

Chris Ryan [21030691] · Sat, 10 May 2008 23:16:00 -0700

It's not clear to me exactly what you mean. The MIDI interface cable on eBay can't substitute for a computer: by itself does nothing, and requires a computer at one end and a MIDI keyboard (e.g. Chroma with Syntech/Chroma Cult or CC+) at the other.

I'm not sure whether "a crappy old PC with Windows 95" will have the hardware (USB port) or software (necessary driver for the interface) in order to use this MIDI cable, but I don't know the specs of your computer.

Jesper Ödemark [21010135] · Sun, 11 May 2008 08:35:05 +0200

I'm sorry for being crappy at explaining. :S

I have a new laptop with vista running (that I write this on). I've kept the old PC with a joystick port and midi interface on a shelf just to be able to upgrade studio gear (I programmed the Drehbank from it for example). BUT... I'd like to free up space and program the same gear (like the Chroma) from this laptop instead. Will that work with the gadget I linked too? I guess it will but I wanted to check with someone who isn't all "Atari-fied" like me. :D

Isn't it bedtime in Canada by now?!

Chris Ryan [21030691] · Sun, 11 May 2008 00:50:16 -0700

I'm a Mac user, so I'm not sure and will defer to any Windows/PC experts on the list.

Isn't it bedtime in Canada by now?!

It is!

SPSU

Åke Danielson [21010068] · Sun, 11 May 2008 13:37:25 +0200

Hi Luca,

Just soldered in the tantalum capacitor and the result is........ IT WORKS!! Pedal mode NORMAL after a SwitchOn. Thanks!

Enrico Dibennardo [21030494] · Sun, 11 May 2008 16:43:34 +0100

What was the value of the cap you used?

Åke Danielson [21010068] · Sun, 11 May 2008 18:58:43 +0200

Hi Enrico,

You have to ask Luca. I'm na NoNo with electronics. I just know how to solder.

Luca Sasdelli [21010226] · Sun, 11 May 2008 22:41:34 +0200

Just soldered in the tantalum capacitor and the result is........ IT WORKS!! Pedal mode NORMAL after a SwitchOn. Thanks!

Hi Ake and all,

GREAT!

All SPSU kit starting from today will have 20uF tantalum cap as reset delay.

Thanks Ake for the feedback!

Luca Sasdelli [21010226] · Sun, 11 May 2008 22:42:50 +0200

What was the value of the cap you used?

Hi Enrico,

the additional capacitor was 10uF, in parallel with the identical one.

Chroma problem

Rikard [21030448] · Sun, 11 May 2008 18:11:54 +0200

Hi,

I am a new member of this list and got hold of a Chroma. However returning home from the shop where I bought it it would not boot up.

I've read about the problem on rhodeschroma.com but it seems more complicated than just fixing the 5Volts. A friend of mine owns a working chroma so he switched cards untill he found out that the problem is located on the I/O card.

My question to you all who have experience in service of the chroma is what usual parts on the I/O card are likley to fail are there any weak links on that card that I should pay extra attention to ?

The Chroma blinks three times and then all the LEDs lit up and there it freezes, no failure codes or anything else can be viewed in the two displays (They do not lit at all during all of this).

Jesper Ödemark [21010135] · Sun, 11 May 2008 19:39:02 +0200

Rikard skrev:

Hi, I am a new member of this list and got hold of a Chroma. However returning home from the shop where I bought it it would not boot up.

Hi Rikard and welcome! (and congrat's to the Chroma!)

The shop? Jam?

I've read about the problem on rhodeschroma.com but it seems more complicated than just fixing the 5Volts. A friend of mine owns a working chroma so he switched cards untill he found out that the problem is located on the I/O card.

My question to you all who have experience in service of the chroma is what usual parts on the I/O card are likley to fail are there any weak links on that card that I should pay extra attention to ?

I just changed the the new PSU (ask Luca on the list, it's worth every öre) and it seems to have solved my problems. Same goes for a lot of other listees...

The Chroma blinks three times and then all the LEDs lit up and there it freezes, no failure codes or anything else can be viewed in the two displays (They do not lit at all during all of this).

The Chroma girl easily gets irritated when you don't feed her the correct voltage. Has there been any battery leakage or similar which is often the case during storage.

Luca Sasdelli [21010226] · Sun, 11 May 2008 23:20:24 +0200

Hi Rikard,

as Jesper wrote, the voltage is crucial for this instrument. Anyway, the fault you describe should be isolated in order to identify the responsible item; I suggest:

  • leave only one voice board installed to minimize board interferences
  • check all PSU voltages if they fall within recommended values (http://www.till.com/articles/ChromaPowerSupply)
  • press [SET SPLIT][31] (special reset) and check voltage across the two test points on I/O board, close to the only one board trimmer: adjust it to read exactly zero millivolts.

If you cannot zero the I/O board test points, it could be a DAC circuitry fault, or a computer board problem, that doesn't supply the correct zeroing code to DAC registers. Did you swap the computer board too?

Posting to the List

Chris Ryan [21030691] · Sun, 11 May 2008 09:22:30 -0700

A few times recently, there have been posts from list members which were sent from non-subscribed addresses. As list owner, I get notified about these posts along with all the actual spam being sent to the list, and must manually approve them for distribution. There has been so much incoming spam recently that I often do not have the time to look at each message before I delete them all, so if you have sent a post to the list that has not come through, this may be the reason.

If you would like to add a subscription address, go to ChromaTalk List Tools.

Re: Chroma in synthesizer magazin

Go to first message in thread, April 2008

Chris Ryan [21030691] · Sun, 11 May 2008 23:30:23 -0700

On 17-Apr-08, at 3:33 AM, jesper wrote:

http://www.synthesizer-magazin.de/mag/wp-content/uploads/2008/04/synmag8.jpg [link dead as of 2009.07]

Just stumbled across this today. It's not out yet I guess but maybe some of our german friends will give us a good review later?

Did this issue come out? Does anyone have a copy?

Jesper Ödemark [21010135] · Mon, 12 May 2008 10:14:13 +0200

Looks like it's available now at least; [eBay item #130221585666]

The English and original German versions of the article were added to the site in September 2008.

chroma halts

Erik Vellinga [21010286] · Thu, 15 May 2008 23:26:18 +0200

Hi Chroma users,

Stubborn me has replaced Chroma's old power supply by a switched-mode PSU. The circuits for 5V analog and RESET could be partly re-used from the HP power supply that has powered my Chroma in the last 10 years. The process has broken the central ADC, DAC and the 8039 on the I/O board. Two days ago I got it all working again, recalibrated and cleaned up.

After adjusting the keyboard feel and dept of keys a new problem showed up. I am way over my head into this at the moment and full of frustration...

Problem is as follows:

  • Main 6809 uP seems to be fine.
  • All voltages within tolerance
  • ERR 01234567
  • No sound after set-split 31
  • No flicker in the display wile touching the keys
  • 8039 keyboard scanner is running but gives no /Read signal to Z34 / Z35
  • DAC adjusted to 0.01 mV
  • All programs selectable and the corr. Led burns
  • Parameters editable and storable
  • But the row of knobs Two Program Link are working erratically, now and than blinking and a slow response
  • Data readout and prog. Nr are fine

So I have basically two problems;

  1. No voice board tuning
  2. No keyboard response.

Main question: Does any one of you knows if the Chroma main computer shuts down the keyboard scanning 8039 in case all voice boards fail to tune ?

What about ERR 01234567 ? What is the most probable place to look ?

Any tips and tricks are VERY welcome

Greeting from sunny Holland,

Erik

Jesper Ödemark [21010135] · Thu, 15 May 2008 23:43:03 +0200

What about ERR 01234567 ? What is the most probable place to look ?

Not sure if this helps at all but mine showed all voices untuned just prior to getting the new PSU. The old showed OK values but I suspect there were fluctuations my voltmeter couldn't detect.

Mark Smith [2103-PT-002] · Thu, 15 May 2008 18:43:25 -0700

Hi -

Hope this helps - - DAC should be adjusted to 0.000 mV

Paul Tillotson [21030218] · Thu, 15 May 2008 20:47:55 -0700

All voices failing to tune does sound like my Chroma just after installing the new power supply but before checking voltages to the I/O board. As has been stated, the voltage to the I/O board needs to be 0 volts. You will get no sound if all voices fail autotune.

Luca Sasdelli [21010226] · Fri, 16 May 2008 11:12:01 +0200

Hi Erik,

which switched-mode PSU has been installed? This just to know it.

Mark Smith [2103-PT-002] · Fri, 16 May 2008 14:36:17 -0700

Hi again Eric -

Those Link Led symptoms could be in part due to a dirty contact or two in the five strip pigtail for the left panel on the I/O board. To clean the contacts, gently pull the pigtail out of the connector, place a flat surface like a small ruler behind it and rub with a pencil eraser, cleaning often.

Erik Vellinga [21010286] · Sat, 17 May 2008 13:14:40 +0200

Hi Mark,

Thanks for your response. I will look into it as soon as I have time. Must be some lose connection or bad contact because I got it all working before adjusting the keyboard depth.

Erik Vellinga [21010286] · Sat, 17 May 2008 14:43:50 +0200

Marc,

Is the DAC involved in the auto-tune process ? Am I correct that a digital word is send to the dual channel bards and the corresponding freq. is measured by the zero-crossing detector ?

David Clarke [21030085++] · Sat, 17 May 2008 08:28:42 -0400

I will look into it as soon as I have time. Must be some lose connection or bad contact because I got it all working before adjusting the keyboard depth.

If it did work OK before the keyboard depth connection, then you're right - the good news is that problem is most likely a bad connection.

As the keyboard adjustment was probably done with the panel flipped up (and as obvious as it may seem) it would be good to double-check that the ribbon cable from the channel motherboard itself is still plugged in to the I/O board (it's easy to accidentally pull it out).

Good luck with your investigation.

Mark Smith [2103-PT-002] · Sat, 17 May 2008 07:20:25 -0700

Is the DAC involved in the auto-tune process ? Am I correct that a digital word is send to the dual channel bards and the corresponding freq. is measured by the zero-crossing detector ?

Hi -

Yes, it is. I don't know exactly how but I do know that the boards won't tune right without that voltage being exactly 0.

Erik Vellinga [21010286] · Tue, 20 May 2008 23:37:16 +0200

Hi,

Got my Chroma working again :) Z10 on the I/O board had blown. This IC is crucial in the auto-tune process.

It seems that if in this case no boards can be tuned there is no keyboard scanning by the 8039 uP as there was also nothing coming out of the computer interface and so no MIDI.

Back to adjusting the keyboard and getting the tapper to work.

Erik Vellinga [21010286] · Wed, 21 May 2008 23:10:12 +0200

Luca wrote, apparently off-list:

Hi Erik,

which switched-mode PSU has been installed? This just to know it.

SUNPOWER SPS060-Q1 60W - €60,95

At www.conrad.nl

Rhodes Chroma Expander for Sale on Ebay

David Clarke [21030085++] · Sun, 18 May 2008 12:12:01 -0400

Not mine, just passing along the listing (as they don't come up for sale that often):

"Powers up and is internally complete but that's about all I can guarantee. Has had a dual bank memory mod done which is what the rotary knob and dual LEDs are for. As you can see from the photos, it is in very good condition for its age."

[Item #250249301991]

As I don't recall a mention in the Registry about a dual-bank memory modification on an Expander, I'm guessing that this unit is not listed there yet.

One of the pictures from the auction:

Erik Vellinga [21010286] · Sun, 18 May 2008 23:07:38 +0200

Nice price [AU$7000]... Better get my saw and sell my Chroma as an expander...

Chris Ryan [21030691] · Sun, 18 May 2008 23:01:19 -0700

Registry Reaches 500 Instruments

This is Expander 16310021, currently owned by Greg Hutchings of Hutchings Keyboards.

And with that, we have 500 instruments in the registry (not including the Polaris)!

Jesper Ödemark [21010135] · Mon, 19 May 2008 08:06:03 +0200

And with that, we have 500 instruments in the registry (not including the Polaris)!

Time to get out that bottle of champagne! :D

Ron Joseph [21030042+] · Mon, 19 May 2008 15:02:06 +0000

With apologies to DClarke, who I replied to by mistake, that's an awfully high price for a possibly non-working expander. I know the market has jumped in the last few years but $6K ?

Jesper Ödemark [21010135] · Mon, 19 May 2008 17:07:02 +0200

We're talking down under here. A guy recently asked 5000 aussie money for a Wasp with a kenton Kadi converter. He lowered to 3000 later but that sure didn't help...

But the amount of vintage gear sure is different down there.

Chris Ryan [21030691] · Wed, 21 May 2008 23:34:58 -0700

The price of the Expander has been lowered to AU $4999.

David Clarke [21030085++] · Sat, 31 May 2008 14:09:57 -0400

'Expander' I/O board

The Australian Expander is back on Ebay (with a lowered price [$3999]).

Looking closely at the pictures I noticed that the I/O board is different than others I have seen.

Specifically, the Expanders that I've stumbled across so far have had had essentially the same I/O board as a Chroma - just with different LEDs in different locations and the Keyboard Scanning processor being removed from its socket.

In this case, you can see that the keyboard-related chips are physically removed from the board (in the lower right-hand corner) with no socket present for the keyboard processor.

This version of the board would seem to have been specifically created for an Expander (vs. a Chroma or an Expander).

Anybody else who has an Expander happen to know what there's is like? (I'm wondering which is the exception and which is the rule).

Chris R. - I think the scratched out serial number is more likely 16330106 vs. 16330406.

Mark Smith [2103-PT-002] · Sat, 31 May 2008 17:23:33 -0700

Re: 'Expander' I/O board

Hi,

Mine is a Chroma I/O board.

Jerry Leonard [21030100++] · Sat, 31 May 2008 20:40:15 -0700

Re: 'Expander' I/O board

My Expander has the socket present with the chip removed.

Go to next message in thread, June 2008

Service Manual on eBay

Chris Ryan [21030691] · Wed, 21 May 2008 22:13:20 -0700

Item #270239422356, ends May 28, no bids yet, starting bid US$99 (!). It looks like either the original ARP version or a photocopy of the later Rhodes one, which of course is available (for free!) at the site.

Pictures from the auction: