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ChromaTalk Archives: May 2009

Safe humidity for Chromas?

Go to first message in thread, April 2009

Chris Smalt [21010280+] · Fri, 1 May 2009 01:25:01 +0200

That reminds me of a show we did around 1986 - it was a frat party with very drunk and sweaty boys and girls in black tie and gala dresses. I guess by now these people are the ones running the country. Anyways, we played down in the basement, where humidity was around 100 %, and water condensed on the cool concrete ceiling and started dripping down from the beams onto the Chroma (atop a Yamaha CP-70). I remember signaling the sound crew, and they moved my entire stack out of the drip zone and tried to dry the instruments with towels, all while we kept on playing.

My Chroma never seemed to care much about its surroundings. It just played on. It didn't like bumpy rides in the back of the sound truck with the flightcase upside down though. Once in a while I'd have to reseat a voice board because it started to act up.

David Clarke [21030085++] · Sat, 02 May 2009 07:11:42 -0400

Does anyone know about humidity? Is there an ideal humidity to keep and run your Chroma in? ... I guess this may apply for any electronic musical equipment, to avoid damage and rusting etc.

Commercial electronics (in general) are designed over work at a wide range of humidity. Many commercial items would like temperatures between +5 degC and +35 degC (ambient) and less than 85% relative humidity.

You certainly don't ever want humidity (or temperature changes) so high that you get condensation on the unit.

You'd also not necessarily want to go to the other side of the humidity question and go to 0%. While it is true that raw electronic components and circuit boards may be stored in a very low humidity environment, once they're installed in the Chroma they're now part of a bigger assembly - and this one includes wood.

Wood will dry out at very low humidity. Also - at the lowest humidity levels, you'll start to easily generate static electricity in the vicinity.

Widely fluctuating temperature and humidity aren't good (in general). That being the case, I wouldn't necessarily suggest then that you put the Chroma directly under the A/C or heater vent.

In most cases, your comfortable inhabited environment would be about the best you could do for the Chroma. (i.e., if you're comfortable in the temp/humidity, then the Chroma is OK too. Perhaps a relatively consistent 40% humidity and 22 degC or so).

My $0.02.

Joe Porter [21030058] · Sat, 2 May 2009 14:02:22 +0000

Thanks

Re: Chroma for sale

Go to first message in thread, April 2009

Ron Joseph [21030042+] · Fri, 1 May 2009 00:06:30 +0000

The finish is more of a walnut color, rather than the more orange cherry wood. The top is a brushed flat black. Jesse, who did Ron's Zebrawood chroma did this one for me...

Jesse rocks !!.....

Tom Klepacki [21030025] · Fri, 01 May 2009 00:29:51 -0400

Hi Ron,

I think that you spelled dyslexia wrong.... It's Lysdexia.... you know, ...when you invert the front and back of things... Just like a Chroma keyboard can! Gee? All Chromas have the ability to become Lysdexic!

Tee-Hee...

(Everyone.... Please feel free to use my little joke, It's not copy-protected. Er, copyrighted.)

Ron Joseph [21030042+] · Fri, 1 May 2009 13:44:37 +0000

"Smirk"... although I have to say, John should have the last laugh: He had to talk me through a fix it job after my Chroma got bumped around in shipping.

Me : Ummmmm, What's this? John ( with the patience of a saint): That's the power supply..and so on

Ron Joseph [21030042+] · Fri, 1 May 2009 13:51:56 +0000

Who's Jesse? I love that Zebrawood Chroma! I've been wanting to get my Chroma and Expander [16330108] done similarly with new exotic wood.

Jesse Moffat is a woodworking artist who works at Cantos with John. A while back, after they created mine, they offered kits for people who wanted to do something similar with their Chromas. The were reasonably priced depending on the wood choice. My Zebrawood is now a halloween Chroma, I should send the final pics. My second Chroma is going to be redone as well. Something like Tillman's..light colored and I'm going to install the gold membrane panels if I can figure out a solution to the membrane panel ribbon connector issue.

PS: A quick shout out to Luca as my power supply drop in replacvement arrived yesterday.

Chris Smalt [21010280+] · Fri, 1 May 2009 16:41:32 +0200

I think that you spelled dyslexia wrong....

Lysdexics of the world, untie!

Randel Osborne [21030467] · Fri, 1 May 2009 10:47:32 -0400

Did you know that 10 out of 3 people are dyslexic?

Tom Klepacki [21030025] · Fri, 01 May 2009 10:49:08 -0400

Lysdexics of the world, untie!

Very good!

Fixed Intonation Issues

Randel Osborne [21030467] · Fri, 1 May 2009 12:17:58 -0400

I think that I've finally fixed the intonation issues that have been plaguing my recently resurrected Chroma!

Prior to my fix, the instrument would tune, with success in all dual channel boards, but the pitch of select voices would drift in very short order, sometimes immediately, up to a half step. At least 4 of the cards would do this, and it was heartbreaking to play.

I recently completed a procedure where I replaced all of the capacitors in the sample-and-hold portion of the Dual Chanel Board (C24-C39), as well as the op-amps that are involved in pitch (Z21 and Z23).

Photos can be seen at: On The Bench - Rhodes Chroma 2.

Although many of the parts that I replaced seemed to have the correct value, I do not have a particularly accurate capacitance meter, and it looks like several of the old caps were oozing electrolytic fluid.

I'm pleased to report that all of the voices now sound great, and are within 10 cents of their designated pitch. I realize that the specs call for 2.5 cents, and maybe it will get there after a 2 hour warm up, at sea level, in 15% humidity, etc. ;-)

I'll post some more information (and clips) once I have replaced the generic circa 1980 op-amps in the audio path with something a little more special and modern. Stay tuned...

german ebay chroma

Jesper Ödemark [21010135] · Mon, 04 May 2009 21:01:31 +0200

Don't know if this has been mentioned, but I just asked the seller for the serial: [item #220404017335].

Jesper Ödemark [21010135] · Tue, 05 May 2009 10:11:52 +0200

21030831 found...

I just received this from the seller of the Chroma on german Ebay.

"hi jesper, here is the number : 21030831"

Luca Sasdelli [21010226] · Tue, 05 May 2009 10:16:41 +0200

Re: 21030831 found...

Er... the shown switched PSU is NOT mine! :-D

Jesper Ödemark [21010135] · Tue, 05 May 2009 10:47:25 +0200

I noticed too Luca. :)

Jesper Ödemark [21010135] · Fri, 08 May 2009 08:51:09 +0200

Re: 21030831 found...

...and sold at 2098 euros.

Chroma "For Repair or Parts" on eBay

Chris Ryan [21030691] · Sat, 9 May 2009 16:11:49 -0700

Item #170330408730, starting bid US$1200, no bids yet, ends May 16.

From the description: "I own another Chroma that needed some work. I bought this one to make one good one out of the 2. The only thing I ended up using from this was 1 voice card. I put the non working card back in this one. This one was working the last time it was used 5 years ago the owner tried turning it on and it didn't work right. My guess is the power supply is out of whack like mine was. I just bought a brand new supply for mine and that fixed all my problems but the 1 bad card. I thought I was going to need a lot more from this one but I don't. I'm running out of room and need to move this. It's in good physical condition couple of scratches. I could have cleaned it up to make it look almost new. The battery had leaked. The bad battery was removed. It is a complete until that needs repair. Selling asis. Don't have extra manuals or cables. I do have an extra dual damper pedal that needs a new wire."

I've asked the seller for the serial number.

Picture from the auction:

Go to next message in thread, June 2009.

A couple of items on eBay Germany

Chris Ryan [21030691] · Sat, 9 May 2009 16:24:41 -0700

TBS (Touched By Sound) MIDI Interface, which looks like a Syntech clone. "Buy It Now" price of €399. Item #350016598934.

Chroma/Expander literature--looks like the brochure along with a document I haven't seen, but which includes a picture that has been on the Music Machines site for many years. Starting bid of €1,00.

Underwood-Harper Patches

Chris Ryan [21030691] · Sun, 10 May 2009 23:35:13 -0700

Scott Harper [21030473] has contributed a number of banks of Chroma patches, most of which are by Ian Underwood (member of The Mothers of Invention, later a film composer). The patches are available on the Patch Downloads page; there were some audio annotations on the tape which I have transcribed. It's always great to get new patches; thanks to Scott.

(It was interesting hauling out my old cassette deck and re-experiencing how fussy the whole loading from tape process can be; it brought back a lot of memories.)

Price History

Chris Ryan [21030691] · Thu, 14 May 2009 19:50:20 -0700

One of the last questions about the Chroma that I have a little bit of difficulty answering is how much they're worth, or at least selling for. I'm putting together a list of historical prices paid, and I could use some help. Before this year, I didn't track winning bids for eBay, and other sales, very carefully; there is some data in the list archives and the owner stories in the instrument registry and I'm digging through them, but it's an incomplete picture. So if you have information on your instrument or others that you would like to include, email me directly the serial number, price paid, and date of transaction, and I'll put it on the list.

Tom Hughes [21030251+] · Fri, 15 May 2009 12:38:13 -0400

I got my Chroma in trade for an A/DA Flanger (for which I paid about $250). The seller informed me that the Chroma was non-functional; but even so, I figured it was worth more than $250 just in parts. That was in 2006. Now it's fully functional with a new PSU and the CC+ upgrade. So I have almost another grand plus many hours labor invested into it as well. And I haven't even started addressing any cosmetic restorations (yet!).

I'm convinced with all the documentation and support available on the rhodeschroma.com website that a Chroma in any condition can be restored to full working order – better than original, in fact. So I'd say a non-functioning Rhodes Chroma at a decent price is probably the greatest vintage synth bargain there is for anyone willing to invest the time and resources required get it working.

Lars Johansson [21030632] · Fri, 15 May 2009 18:45:51 +0200

Shhhh.......don't spread the word !

;)

Access to extra patches in expanded CPU

Joe Porter [21030058] · Wed, 27 May 2009 21:39:10 +0000

Hi,

I am just about to install the CC+ into my Chroma. I have additional patches on the old CPU (an expansion PCB attached to it). When I bought I was told that it had twice as many patches as normal Chromas.

I'd like to access these before I install the CC+. Does anyone know how I can access these additional patches before I potentially loose them?

David Clarke [21030085++] · Wed, 27 May 2009 21:33:27 -0400

Joe - the specifics of the expansion PCB will dictate how to select the other banks.

If it is like the one seen here [Chroma Cult Memory expander for the Chroma], then you'd be looking for some add-on switches to be present on the Chroma. Once you have one of the other banks selected, you should be able to save (as normal).

Joe Porter [21030058] · Thu, 28 May 2009 12:41:31 +0000

Hi,

Yes that is exactly the expansion board.

I have two switches to the right of the ebonies/ivories. I have tried switching them before though, and it only seemed to shift down an octave on some of the patches. Is there something else I need to do?

Ken Ypparila [21030229] · Thu, 28 May 2009 09:32:44 -0700

With the two switches you get 4 times the normal memory storage. For each combination of switch positions, both up, both down, one up one down, you get a new bank of 50 programs. The current program does not change when you select a new memory bank. You must select a new program after you switch banks. To load or save a bank of 50, change the memory bank switches first and then save or load a new set with whatever method you have available. To bounce a program from one bank to another, select the program, change the bank, then save the program. I hope this helps.

Lars Johansson [21030632] · Thu, 28 May 2009 18:36:20 +0200

Maybe it is the same patches but some transposed in all banks ?

Go to next message in thread, June 2009

Two Voice Boards on eBay

Chris Ryan [21030691] · Sun, 31 May 2009 16:34:08 -0700

Items #220425615071 and #220425023399, apparently for sale by Russ Lyons [21030574], who auctioned off a couple of voice boards in late 2004. Starting bid US$140 (each), "buy it now" price US$150. Both end June 7.

From the description: "Auction is only for U.S. bidders in the contiguous 48 states. Please don't ask me to ship elswhere. Rhodes Chroma Voice Card, working, removed from synth. Some of the cards have some socketed IC's. probably due to repairs. These cards are rare, I have only seen a few others for sale over the years, and I sold some a few years back. The filter chips (CEM3350) alone cost $60 each and I only have seen two left, I think they are in Denmark! Sold as-is, due to age and shipping, no refunds or returns."

Picture from the auctions:

eBay Item #220425023399

Chris Ryan [21030691] · Sun, 31 May 2009 18:56:18 -0700

Another voice card has been added by the same seller: item #220425721840. All details the same as the other two.

Russ Lyons [21030574] · Sun, 31 May 2009 23:56:53 -0400

Ebay assigned the voice cards new item numbers:

  • 220425800258
  • 220425801333

Go to next message in thread, June 2009

Spare Parts on eBay

Chris Ryan [21030691] · Sun, 31 May 2009 19:01:11 -0700

Item #220425668680 (same seller as the voice boards mentioned today) includes:

  • A full set of keys from the Chroma
  • The left cheek block with the pitch bend and mod lever
  • The plain blank right cheek block
  • A bag of round felt bushings
  • A tapper solenoid
  • The two balanced audio tranformer board ???
  • The EQ board, has two CEM3360 VCA chips, expensive/hard to find.
  • The contact assemble for the keyboard, has a little pitting/corrosion, needs cleaning.
  • The Chroma interface cable for hooking two together, or expander or Apple II computer.
  • Misc. harness.

Seller writes, "I will not sell any of this seperately, please don't ask. The Chroma these are from worked, but the I/O board was flakey (acid damage battery leak), but I just couldn't get it to be stable. Sold as-is, due to age and shipping, no refunds or returns."

Starting bid US$90, "buy it now" price of US$125, ends June 7. Again, U.S. bidders only. :(

Picture from the auction:

eBay Item #220425668680