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ChromaTalk Archives: November 2005

Re: New owner!

Go to first message in thread, October 2005

Tom Klepacki [21030025] · Tue, 01 Nov 2005 10:02:10 -0500

I'm there... BUT, since I cannot get to the anvil case easily, ...open the coffin, and look at the body.... I'm in that 'other' category, until I read and confirm the 21xx model number.

Ron Joseph [21030042+] · Tue, 01 Nov 2005 17:36:54 +0000

How do you know which model #'s consisted of the first 50 i.e. 2103, 2102 etc.? My serial # is 21030042 and I've assumed mine was also one of the first 50. The front panel membrane switch #2 is different (Poly/Mono) and the last key on the keybed (g) is a different color. It's white versus the ivory color of the rest of the keyboard. J.L. [21030434++] at Cantos said he serviced another one that had the same high g key replacement.It also was one of the first 50 in the 2103 series.

Does anyone know if this was typical and why it occured? Are the keys of a different type on the first 50? What about the other parts like voice boards etc.? i know from the list there have been several variations but were there any other differences to the first 50, positive or negative,other than the "hand assembled"part.

Finally,congrats on your new Chroma and welcome to the list. Was your purchase the one from Australia on ebay last week? If not we should contact the winner of that auction as well.

Thomas Story [21030352] · Tue, 1 Nov 2005 13:10:28 -0800

ok, problems with newbie

Allright, so got it home last night after seeing Bauhaus, plugged it in, powers up, lights flash, hooked up to mixer...no sound...

err 02356

now what?

Downloading the service PDF as I write.

Help!

Vincent Russo [21030433] · Tue, 1 Nov 2005 16:26:13 -0500

dare I say, replace battery, clean the key contacts, load in a sound bank or call up the default sound. After that, Ill will let the tech guys take over.

Olli [21010284] · Tue, 1 Nov 2005 22:30:25 +0100

Re: ok, problems with newbie

maybe just a problem with the contacts (molex connectors inside the synth..) either it needs reseating the voice cards, a voicecard repair or a motherboard repair. not impossible to do for the hobbyist. i have done it. check if and what voicecards are broken reseating them and switching slots on the motherboard. put in one card at a time. this wasy you can identify if its the specific card and/or the motherboard. the archives are full with tips how to procede and which setsplit commands are useful to identify the problem on specific cards. good luck.

Thomas Story [21030352] · Tue, 1 Nov 2005 13:39:35 -0800

Re: ok, problems with newbie

ok - found severly corroded battery contacts, seems like there might be some corrosion spilt over onto the CB..I've pulled the board, should I pull the IC;s and clean the corrosion with baking soda, dry it, new batteries and try again?

Vincent Russo [21030433] · Tue, 1 Nov 2005 17:05:24 -0500

Re: ok, problems with newbie

When we bought our Chroma the battery assembly was full of battery corrosion and falling apart, so tech Julie Yarborough cleaned the area around it and replaced it with a new battery assembly. Im betting if you can clean it up and it still works, you can add new batteries and hopefully new sounds through MIDI if you have a interface or the default sound just to test it. Note, were no techs, but just sharing are experience which sounded similar to yours.

Henry Salvia [21030307] · Tue, 1 Nov 2005 13:31:32 -0800

Re: ok, problems with newbie

Allright, so got it home last night after seeing Bauhaus, plugged it in, powers up, lights flash, hooked up to mixer...no sound...

err 02356

Means boards # 0,2,3,5 and 6 failed power-up diagnostics, and have been disabled. Means boards 1,4,6 and 7 should be "on". But, "no sound" so you got other problems. Go read the Troubleshooting section on www.rhodeschorma.com [see Hardware Fault Diagnosis & Repair]. If you can't make heads or tails of that, then just hand it off to a tech. The Chroma is pretty basic by contemporary digital standards, but it is a computer with mixed audio/digital stuff in there.

Despite what someone else said, I always had good service from CAE, but I haven't been down there in years, so things may have changed... But since my Chroma doesn't seem to want to hold a patch, I guess I should check it out.

Chris Ryan [21030691] · Tue, 1 Nov 2005 15:12:27 -0800

How do you know which model #'s consisted of the first 50 i.e. 2103, 2102 etc.? My serial # is 21030042 and I've assumed mine was also one of the first 50.

I don't think we have a definitive answer on this. There are some Chromas with absent or unusual serial numbers, which may have been within the first 50.

One possibility is that the first 50 were a mix of model numbers. What we have in the registry includes: 

21020003
21010004
21010006, 21040006
21040011
21040012
21040016
21010021
21010022
21030023
21030025 [unknown model number until 2008]
21010034
210?004?
21030042
210?0044
210?0046

There is, so far, only the one duplicate (0006) across model numbers. For me, that's not quite enough evidence; one of these people may have made an error in reading or typing the serial number.

The front panel membrane switch #2 is different (Poly/Mono)

But I assume it has the usual function (FSW MODE), at least as long as the firmware has been upgraded?

and the last key on the keybed (g) is a different color. It's white versus the ivory color of the rest of the keyboard.J.L. at Cantos said he serviced another one that had the same high g key replacement.It also was one of the first 50 in the 2103 series.

Interesting. I'd not heard of this before.

See follow-on thread First Chromas, below.

David Clarke [21030085++] · Tue, 01 Nov 2005 19:10:17 -0500

Re: ok, problems with newbie

ok - found severly corroded battery contacts, seems like there might be some corrosion spilt over onto the CB..I've pulled the board, should I pull the IC;s and clean the corrosion with baking soda, dry it, new batteries and try again?

Depending on how the keyboard was positioned/stored when the batteries leaked, there may have been 'drippings' back towards the key contacts and/or voice boards.

Follow the acid trail whereever it goes and clean anything you can (inspecting the traces of the circuit boards as you go).

Tom Klepacki [21030025] · Tue, 01 Nov 2005 21:10:22 -0500

When I can access mine, I will check my #25 for a different key color. Interesting.

By the by, Ken Ypparilla was offering his Syntech retrofit as of 9/16/86, as I found a letter from "Keyboard Specialties", offering Ken's retrofit. I also have a photocopies of Ken's sales literature, as well as J.L. Cooper's, from that exact time frame.

Help anybody? Does the site need photocopies of this literature?

Tom Klepacki [21030025] · Tue, 01 Nov 2005 21:15:59 -0500

Re: ok, problems with newbie

Battery corrosion? Baking soda???? Are you brushing your teeth, or are you cleaning out electronic 'gunk'?

Get some CAIG De-oxit products. ASAP. The stuff used to be called 'Cramolin'.... Squirt, brush, swab, scrape... and swab the crap out...

Tom Klepacki [21030025] · Tue, 01 Nov 2005 21:40:43 -0500

Again, as per my previous email...

CAIG De-Oxit.... Carefully spray the stuff intoall Molex connectors (and mating connectors) (Plus any other similar connectors!), THEN, reseat. Swab clean, inspect with a magnefying glass, scrape (even with a needle, or a tiny file), spray, swab again.... should be clean... Reinsert... Cross your fingers... And pray to the gods of electronica...

Think "Bonnie and Clyde", for 95% of most electronic repairs. "Dirt in the fuel line... Just had to blowed it away". Really.

I am of the opinion that most components (resistors, transistors, IC's, circuit boards) will last a very long time. The 'connections' between them get full of crap, and fail.... (An exeption may be capacitors, for instance, that just may dry up, and fail, needing replacement)

Of course, there may be an actual component failure, such as a $.29 resistor, which crashes the whole friggin' machine....

Uro [21030401] · Tue, 1 Nov 2005 21:48:31 -0800

Take it to Greg [Analog Synthesizer Service]: you may have the fortune that mine will be there for comparison, entrails also on display. Greg fell in love with my Chroma after I took it to him the first time (there were no problems and I paid $700 for it from Doug T.)-- and this is for a big guy who breathes Sequential IC's!

I've also been asked to expound on CAE: went there for a visit about 10 months ago at a suggestion of someone else. They were downright rude, their rates are average, but they spend more time than necessary because they often don't know the problems themselves. E.g., my Sound Engineer brought a mono-Pro One in for repair there and dropped $150 for calibration and tuning! Not even any parts, just all labor! I personally hope none of you ever go to them again-- but I can't stop you.

I don't mind spending the money if someone knows what they are doing. With most keyboards, they don't and Greg does (except Moogs--for those I send it to Julie Yarborough in L.A. (just got back my MINI W/MIDI) who does a great job or Mike Bucki in NY (currently finishing a DBM MIDI upgrade to my MM+).

Julie is also an excellent all-around tech. in CA and has worked on many, many Chromas-- a complete (and thurough) professional.

Good luck, because you'll need it. And, btw, I'm seeing Bauhaus in New York because they sold out their HellDay show last night: I don't hear any Chromas on their tracks, but that doesn't mean a remake could be made that does ;).

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 08:02:27 +0100

I think the fourth digit is more interesting - does anyone here know the story behind it? Assembly group? I guess I was naive to think the 2101 was the first batch and 2104 the last...

Chris Ryan [21030691] · Tue, 1 Nov 2005 23:14:03 -0800

I think the fourth digit is more interesting - does anyone here know the story behind it? Assembly group? I guess I was naive to think the 2101 was the first batch and 2104 the last...

Take a look at the corresponding registry pages. Model 2101 seems to have been made for Europe; 2103 sold in North America; and 2104 in Australia. We only have a single 2102, originally purchased in Sweden (and recently sold). There are model 1631 and 1633 Expanders (presumably for Europe and North America again, respectively).

See also "What is the difference between models 2101 and 2103?" in the FAQ.

Peter Carss · Wed, 2 Nov 2005 01:21:14 -0500

Re: ok, problems with newbie

Actually vinegar is the best thing for battery corrosion. *remove* the battery holder from the circuit board and give it a soak in some, and you'll see lots of foaming as the vinegar neutralizes the alkaline residue from the leaking batteries. When it stops foaming, rinse thoroughly in very hot water, blow dry and reinstall.

Worked great on the expander I sold in the spring.

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 08:20:24 +0100

Take a look at the corresponding registry pages. Model 2101 seems to have been made for Europe; 2103 sold in North America; and 2104 in Australia. We only have a single 2102, originally purchased in Sweden (and recently sold). There are model 1631 and 1633 Expanders (presumably for Europe and North America again, respectively).

Cool, so 2102 is for Sweden then! ;) I still haven't heard from the other known Sweden-sold chromas yet... :(

See also "What is the difference between models 2101 and 2103?" in the FAQ.

I'll check that on the double...

Tom Klepacki [21030025] · Wed, 02 Nov 2005 12:39:18 -0500

Re: ok, problems with newbie

Okay... Then, after vinegar cleaning, raw metal parts should be coated with de-oxit 'blue', corrosion preventative.

Studio engineers turned me on to 'Caig' years ago, and I'm a big fan of their products. Scratchy pots or faders? Corrosion in connectors? Leaky batteries ruin a flashlight, handheld electronics, or stomp boxes? Caig de-oxit, a scraper, and wooden swabs will save them.... It's expensive, like $7.00ish for a small spray can, but worth every penny. Also in brush-on liquid.

Ola [21020003] · Wed, 2 Nov 2005 18:06:48 +0100

Cool, so 2102 is for Sweden then! ;) I still haven't heard from the other known Sweden-sold chromas yet... :(

I'm here now, and full enjoying the lovely Chroma :)

Thomas Story [21030352] · Thu, 03 Nov 2005 02:00:02 +0000

Hey, thanks for the input...

Just brought my VS (which is down a voice) and the Chroma to Greg, who is like, 2 miles from my girlfriends house! Super nice guy, thanks, I'm psyched to find someone like him so close. I did go through the unit, cleaned the corrosion (thanks for all the tips), replaced the batteries, re-seated all the connectors...to no avail...as much as I love projects, the thought of it sitting in pieces for realistically a few months without necessarily fixing the problem just convinced me to nip it in the bud right away and contribute to someone else's beer fund, or boat payment or whatever and just spend more time tweaking my Studio 440.

I had brought my VS to CAE a couple years ago, and he did fix a power supply problem, but did not fix the missing voice issue. Cost 200$ and took him about 3 months, so yeah, I do appreciate somewhere new to go...

He did say he'd have your Chroma in, so it would be easier with 2 machines to figure stuff out. What's wrong with your machine? Keys out of adjustment?

Uro [21030401] · Wed, 2 Nov 2005 21:57:57 -0800

Good, you made the right decision on Greg.

It will help him to have both Chromas there, yes. I hope my known issue is only two keys (lowest G and second highest E) not playing sound, either directly or through MIDI: could be just dirty key contacts.

He's actually a Sequential guy so he'll know your VS pretty well. Can you give him permission for him to show it to me when I'm over there on Sunday? I'd like to hear it to see if i'd like it.

Thomas Story [21030352] · Wed, 2 Nov 2005 22:15:35 -0800

of course! Yeah, I can't wait to get them back!

thanks again

Polaris Advertisements

Chris Ryan [21030691] · Tue, 1 Nov 2005 08:41:41 -0800

This month's update to the Chroma site includes scans of a number of Polaris advertisements--the product brochure (thanks to Paul Hackett-Evans) and magazine ads, some of which feature the pre-production prototype colour scheme.

Another Chroma For Sale

David Clarke [21030085++] · Tue, 01 Nov 2005 18:56:46 -0500

... Christmas must be coming, as there's another Chroma for sale on eBay.

This one is in the registry (21030450).

(Ebay Item # 7362739587).

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 08:03:56 +0100

UGLYuglyUGLY fan modification!

Brian Silva [21030450++] · Fri, 04 Nov 2005 09:40:35 -0500

Re: Chroma on eBay

Hello Everyone,

I'm the one who recently listed the restored Chroma on eBay. I pulled the auction yesterday. I took it off eBay mainly because I was going to regroup and package it with a brand new foam lined, ATA type case from the New York Case Co., after which I was going to relist it and open the auction up to Europe and Canada. It would be the safest way to ship it. The case won't be here for the next couple of weeks. However, I was playing it last night down in the studio. I had just recently had it completely restored and hadn't put the patches in until then. It's the first time I have ever really gotten to put it through its paces since I got it over a year and a half ago. I've decided it's the biggest, baddest, most unbelievable synth I have ever heard or put my fingers to. . .and I own a Memoymoog as well as a slew of other synths. It kicks the crap out of most everything. My old Oberheim Xpander would have had to hide its head in shame. I may not be able to let it go at all. . .I'm in love with it!!!

Site Hosting Expenses

Chris Ryan [21030691] · Tue, 1 Nov 2005 23:59:39 -0800

The Chroma site has been up since February 1999. This January, after six years, I finally moved it to its own domain. I found a good, relatively cheap, local hosting company.

The site has, of course, never generated any revenue. I've never seen this as a problem; I think there's real value in keeping things free, and what I give to the Web I get back a thousandfold (not to mention how much I learn by developing and maintaining the site). I've always had a bit of a distaste for ads, and begging for money is not necessary: the site is not a financial burden for me.

However, several people have suggested they would donate.

And there are some attractive things about Google AdSense: as John Gruber pointed out a couple of years ago, the ads are just text; there are no "get rich quick" type ads served; and there's no JavaScript trickery. The New York Times recently had another interesting article [Google Wants to Dominate Madison Avenue, Too]. I don't know if the program would cover the cost of hosting rhodeschroma.com, but it might: in October there were over 3300 visitors who viewed more than 19,000 pages (though AdSense is pay per click, rather than impression). On the other hand, Gruber later dropped the ads from his site in favour of a membership drive.

I want to be clear that I'm not in dire financial straits here, but the thought of the site being self-sustaining at least in terms of hosting costs (as opposed to my time) is somewhat appealing. I wondered what your thoughts, as probably the core users of the site, would be on this. The alternatives are:

  1. Optional donations (e.g. through PayPal);
  2. Google text ads (probably only on the home page);
  3. Continue as is, free of even the smallest nag.

To be clear, I have absolutely no problem with #3 if that's what people think is best.

Feel free to respond on or off list with your thoughts.

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 09:05:05 +0100

I think optional donations is a splendid choice but I have no problem with alternative 2 or 3 either...

Jerry Leonard [21030100++] · Wed, 2 Nov 2005 14:07:40 -0800

Chris,

My vote is for option #1. I would be happy to donate through paypal. I've long thought that you should be compensated for the excellent work you've done and your time. I actually don't spend much time on the site itself, but I ALWAYs read the email from the subscription list.

Whatever you decide to do would be all right with me.

Mike Jaynes [21030638+] · Wed, 2 Nov 2005 18:22:47 -0500

Chris;
I like the option of the paypal "contribution" model. I am somewhat skeptical of the click based revenue generation schemes as many of these have been hijacked, (see Commission Junction Bans Major 'Loyalty' Affiliate by Brian Livingston) perhaps the Google model has this figured out.

I have used sites where there is a paypal logo for the users to volutarily contribute. Sometimes a suggested amount and/or a page with a list of contributors (with just names) can help this model along. I think a yearly donation of $20-$40 can go a long way to help defray the hosting costs.

Whatever you do will be OK with me. Keep up the good work.

Paul Hackett-Evans [21010094] · Thu, 3 Nov 2005 00:39:51 -0000

Hi Chris,

Personally, I'm completely opposed to any kind of commercial advertising on websites, as I find it really irritating. We get bombarded by advertising wherever we look these days, it feels like were never free of the salesmen. A website thats free of ads is a much nicer place to be. Id prefer to donate or subscribe via Paypal. I really appreciate the work you put into the Chroma site. In my opinion, its one of the best websites of anything on the internet.

Jack Colburne [21030142+] · Wed, 2 Nov 2005 18:45:17 -0500

My vote is for option #1

Ditto. But, whatever you decide to do would also be all right with me.

All of Chris' (your) work has, personally, given me a different and healthy connection with my past than I'd had before. Kinda helps validate it by my "today's standard". I get a sense that there are other people here who've moved on to different places and worlds and appreciate the connection to one that we knew well and, maybe, loved. Sounds ridiculously corny, but I've sort of bridged the identities and that makes me feel more content with what I have and don't have now.

And if all that actually just comes from me... then Chris's work has certainly been a catalyst.

Tom Klepacki [21030025] · Wed, 02 Nov 2005 22:01:48 -0500

I will paraphrase and insert my remarks into other people's remarks....

My vote is also for option #1. What do you feel would be a fair donation to continue this site/ fraternity? I do not do PayPal... I would mail a check...

But, whatever you decide to do would also be all right with me.

All of Chris' work has, personally, given me a different and healthy connection with my past than I'd had before. I feel that the connection to other Chroma owners is kinda like a family tree... That we are part of an elite "Chroma" tribe...(Do I smell a TV reality show..? The Chroma Cult...Whooooooo!)

Chris's work has certainly been a catalyst, and is much appreciated...

After joining in with the rest of you, I just wanna uncrate my Chroma, and restore the sonofabitch... It was SO good, until it died...

[21030691] · Sat, 12 Nov 2005 16:52:51 -0800

Donate to rhodeschroma.com

Thanks for the feedback on site hosting expenses. The comments I received convinced me that a donation system, rather than ads, are the way to go. You can now donate to the site using PayPal, via a button on the home page which takes you to a donation page which in turn sends you off to paypal.com. As a small token of appreciation, to those of you who donate I'm making available the URLs of a few hidden pages and features of the site that you might find useful or interesting. If you don't see these at the end of the PayPal payment process (be sure to click the Continue button on the Payment Complete page at the PayPal site), send me an e-mail and I'll get the info to you.

I'm not going to write an a essay about how much, if anything, you should donate. If you want to contribute, just consider what the site is worth to you. The only thing I will say is that it costs me about US$100 per year in hosting charges. But you won't hear me complain too loudly if what I receive goes a bit beyond that; there are lots of other related hardware and software expenses, they're just difficult to quantify as they're not one hundred percent dedicated to the site.

I figure that you'll only hear from me on this subject approximately annually if there's a shortfall in covering hosting expenses. Not that I expect them to be covered necessarily, but just to let you know where the fund stands. I don't want this to add any more noise or overhead to the list or site than it has to.

So thanks again for the feedback, and for the initial suggestion from those of you who generously came forward with offers to donate. Thanks also to David Clarke [21030085++] who helped test the donation process.

Tom Klepacki [21030025] · Sat, 12 Nov 2005 22:09:06 -0500

Re: Donate to rhodeschroma.com

I'll be glad to send you some money... The site is valuable.... But, I do not have a PayPal account. Please post an address, or PO box where (non-PayPal) idiots like me can send you some money to continue the fine work that you are doing!

Chris Ryan [21030691] · Sat, 12 Nov 2005 19:23:36 -0800

Re: Donate to rhodeschroma.com

As stated on the donation page, I'll be happy to send a postal address directly to anyone who doesn't have (or want) a PayPal account. I don't want to post an address on the site, for fear of generating junk mail (that 20th century equivalent of spam!).

Thanks!

Paul Hackett-Evans [21010094] · Sun, 13 Nov 2005 11:29:27 -0000

Hi Chris,

I'll donate when I've been paid next!

expander and separate synth

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 11:02:31 +0100

Hi List!

If I buy an Expander with Cooper midi interface, I guess that means I can use it as a separate synth altogether?! I know, basic question, but I cannot find it on the site and I'd like to hear from experts if it'd be a good idea to get one as a second polysynth for my studio.

What is a decent price for a fully working unit. Personally I think the keyboard versions should be more expensive since they have the splendid keyboard... but the expander is a lot more rare so...

Let me know!

Lars Johansson [21030632] · Wed, 2 Nov 2005 12:22:20 +0100

Yeah Baby Yeah !!

Jesper = Chroma man

LJ = PPG man

;-)

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 13:56:18 +0100

Oh no, I'm the EDP-man... always! ;)

Lars Johansson [21030632] · Wed, 2 Nov 2005 14:04:00 +0100

Just checking ;-)

LJ - Maybe I should unpack that Chroma that's sitting in my garage.......

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 14:19:48 +0100

LJ - Maybe I should unpack that Chroma that's sitting in my garage.......

The one you're suppose to fix - unpack dude! Wasn't that one of the unlisted ones too...

Lars Johansson [21030632] · Wed, 2 Nov 2005 14:30:35 +0100

The one you're suppose to fix - unpack dude! Wasn't that one of the unlisted ones too...

Alright then, I'll unpack it.

I'll start fixing it when I get the ok to do so from the owner.

electronically yours, jesper, along with LJ a Simmons man too ;)

Tjoff tjoff...

Lars Johansson [21030632] · Wed, 2 Nov 2005 15:50:43 +0100

Serialnumber is 21030632

Jesper Ödemark [21010135] · Wed, 2 Nov 2005 16:07:56 +0100

Cool - not on the site and just next to the Halloween Chroma if you send a little note to Chris... ...and I see Ola's name on the 2102-chroma... good that the site gets updated... :)

First Chromas

Ron Joseph [21030042+] · Wed, 02 Nov 2005 18:29:11 +0000

Another interesting difference is that my Chroma doesn't have grills in the top. Considering its condition when I got it I'd assume that was original not an alteration done later. Did the earlier model 2101's have the Arp voice boards? If they didn't we could assume that the 2103's came first,up to a point, w/ the other models ccoming into play when Rhodes developed a distribution netwoprk in Europe, Australia etc. Just a thought.

Tom Klepacki [21030025] · Wed, 02 Nov 2005 14:46:02 -0500

AHA! You jogged my memory.... When I bought my #25, it came with a top without vent grills. When I brought it to Woburn, they changed the logo, replaced the top cover to one with grills, (for an attempt at heat dissipation) did some kind of revision to the OS, and replaced a board or two.

CEB firmware update

Sandro Sfregola [21010294] · Wed, 2 Nov 2005 19:35:43 +0100

A firmware update for the Chroma Expansion Board is available on the site: rev 20.8.

Fixed a bug in the system exclusive load section (it was accidentally introduced in rev207).

Christian Kleine [21030210] · Wed, 2 Nov 2005 21:04:46 +0100

Hello Sandro,

Is there any way purchasing a complete CEB?

Sandro Sfregola [21010294] · Thu, 3 Nov 2005 22:21:08 +0100

about CEB

Christian - a complete assembled CEB is not available at present but the new CPU board is at a good stage of development (we are at testing level) and things proceed as scheduled.

I would remind to you and to all the list members that the board will be available assembled and tested at a convenient price and the installation will be very simple (as opposite to the CEB), even for non-technical people.

The expanded CPU feature the CEB capabilities and more: more memory, alphanumeric display interface, no battery etc.

I suggest you to wait a little more (Xmas gift?) :->

Ron Joseph [21030042+] · Fri, 04 Nov 2005 01:26:22 +0000

Re: about CEB

Can't wait to purchase the new board Sandro. Great work!

Jesper Ödemark [21010135] · Fri, 4 Nov 2005 08:14:09 +0100

Re: about CEB

We're looking forward to it Sandro...!

Werner Schöenenberger [21010114] · Fri, 4 Nov 2005 19:18:11 +0100

Re: about CEB

Hi Sandro,

this sounds very promising. Please keep us updated of your next steps.

Vincent Russo [21030433] · Fri, 4 Nov 2005 14:34:45 -0500

Re: about CEB

We will get two now Sandro, seeing our Expander is on the way : )

Sandro Traversi [21010217] · Sat, 5 Nov 2005 13:34:03 +0100

Re: about CEB

Sandro (& Dave), complimenti davvero. Grande progetto.

RSS Feeds

Chris Ryan [21030691] · Wed, 2 Nov 2005 18:51:40 -0800

... I see Ola's name on the 2102-chroma... good that the site gets updated... :)

Just a reminder that, if you want to track changes to the site beyond the monthly update which I announce to the list, there are RSS feeds for the Chroma and Polaris. RSS is growing so quickly in popularity, you may have heard of it since the new site launched in January.

Point your favourite RSS reader to:

No need to set your aggregator to check these more than, say, once a day.

cem 3310

Claes von Heijne[16330008] · Sat, 05 Nov 2005 11:47:04 +0000

Anybody who has functional cem 3310 for sale?

David Clarke [21030085++] · Sun, 06 Nov 2005 11:40:33 -0500

If you can't find them anywhere else, I'd check with Wine Country. The Prophet 5/Prophet 10 used a lot of these (and they were in the Pro-1 as well), so I'd expect them to have quite a few still on hand.

voicecard repair

Claes von Heijne[16330008] · Mon, 07 Nov 2005 08:57:46 +0000

My old Chroma 21030290 has suffered the last years. Its been in a shop, it boots up, plays in tune, but voicecards 4,5, and 7 are ill, if I put them in the whole instruments stops before even booting up (16 blinks) procedure, when taken out, there is a ten blinks booting up procedure, and I have a 5 voice Chroma.

I'm no tech, I studied the excellent documents on fault diagnosis on this incredible site (has any other instrument such a service?), it seems that week power supply could be dragged down by every other device that it has to feed, so that an extra voicecard could be the problem, but I have a feeling that its the voicecard and not the powersupply that is faulty, since they deliver audible cracks and unwanted noice when I insert them, they are full of cems and things that could be wrong.

My question:

Is there anybody who takes in the voicecards for repair, sinde they've repaired lots of them and has no problem with it? Its easy to ship voicecards, hard to ship the whole synth. The techs in Sweden has seen so few of the instruments that the learning costs are prohibitive.

best regards

Jesper Ödemark [21010135] · Mon, 7 Nov 2005 10:08:00 +0100

Hi Claes!

I cannot recommend any special tech, but maybe LJ (up in Piteå) who has a faulty chroma he's working on can help out?! Otherwise I know a few skilled dudes in Stockholm. None with a Chroma though...

Haven't found Anders either, have you?

Paul Hackett-Evans [21010094] · Mon, 7 Nov 2005 09:41:09 -0000

Hi Claes,

Roy Paynter can do this for you. He currently has a couple of Chromas in for repair, and he'll have mine for a bit of maintenance in about 2 weeks time.

I'm sure it won't be costly to send them to the UK packed securely.

If you'd like Roy's contact details, let me know.

John Leimseider [21030434++] · Mon, 7 Nov 2005 08:57:43 -0700

I've got a Chroma here and I do repair individual boards... We [Cantos Music Foundation] charge $70 Cdn per hour plus parts. If you want to send boards, please Email me first to get the shipping details.

Bob Doucette · Wed, 9 Nov 2005 09:41:03 -0500

Can anyone help

I have a Chroma Polaris 2123 in for repair it belongs to an elder Priest. I told him say a few prayers and bury it however he still thinks it has life.

I nee the green membrane switch pad they are two one on each side that gets plugged in the middle. Any help will be greatly appreciated

John Leimseider [21030434++] · Thu, 10 Nov 2005 08:26:23 -0700

MusicTek bought all that Fender had left about 10 years ago. They may still have some, but they're expensive. The phone is 818 506-4055.

Vincent Russo [21030433] · Thu, 10 Nov 2005 11:42:11 -0500

I have been trying to get a few pots from them for another synth for while now. Just be forewarned they can be extremely slow.

Another new Chroma on Ebay

David Clarke [21030085++] · Tue, 08 Nov 2005 21:09:55 -0500

S/N #21030189 (for pickup only, in Sterling Heights, MI)

Ebay Item #7364937735

It looks like it comes with the case and Pedals. Starting bid = $199 (how can you go wrong ...)

loading sound

Claes von Heijne[16330008] · Wed, 09 Nov 2005 12:41:25 +0000

I started to fool around with the old Chroma again, 5 voices out ot 8 sound, the 3 faulty go on repair, it turns out the cassette interface is either disconnected or faulty, the deck and tape are ok, the synth doesnt load. You can tell there is something missing in the link, the chroma hears nothing of the tape, because you could allways overhear it through the output.

Fortunately all sounds are on the site, I have syntech interface, logic 4.7, everything hooked up, the syntech in default position. There must be a possibility to let the logic load the chroma through the syntech, never done it.

  1. How to get the logic to load the .sit files?
  2. How to be sure the syntech accepts and transmit it.
  3. I'd like the syntech to send 2 receive 8 channels (though 5,6 and 8 will not sound) What are the commands to obtain this?

Another question to: I'll have to have the chroma fixed, the bass-middle-treble is not good, to what extent does this unit contribute to the overall noice that allways went through it. I allways found these controls unusefull and play the instrument with all of them all the way up, can they me sidestepped at repairjob and the noice reduced at the same time? Also; does the main volume out add to noice, or the other way around, if main volume was always set to max inside and the main volume slider including circuitry disconnected, would noice in realtion to sound be lower? Totally amateur speculation, but somebody knows?

Of course a renovarion should be in direction of the original, but reducing noice is high priority for me, in recording situations this was allways an issue.

Jesper Ödemark [21010135] · Wed, 9 Nov 2005 14:09:55 +0100

Yes, if the pots themselves are bad, a bypass can help, but the basic idea of a volume pot is that max is max, no resistance whatsoever and none or more or less no resistance... On the EQ business I cannot answer...

I think changing a crappy pot to fresh one is a better idea though!

Stu Ervin · Wed, 09 Nov 2005 13:29:10 +0000

Sometimes noisey controls can be cured by simply spraying a cleaning fluid into them.... You can buy this "contact cleaner" at most tv repair stores, music stores, radio shack, or on the web...

Paul Hackett-Evans [21010094] · Wed, 9 Nov 2005 14:49:47 -0000

Hi again Claes,

My Chroma's virtually noiseless. It took Roy a lot of work replacing old capacitors etc but even at high volumes, noise just isn't a problem at all. So it must be possible to cure your problems, Claes.

Jesper's right about the volume control. The volume pot either allows full output to pass unhindered, or it reduces it. You should get the best signal-noise ratio with the volume pot all the way up.

However, the EQ section should be left with all 3 sliders in the centre if you wish to have a neutral EQ. If you take the sliders below centre, they cut frequencies, and if you raise them above centre, they boost them. If you have a noise problem, boosting the EQ as you are doing will make the noise seem worse, as it will be boosted together with the EQ frequencies in the signal.

I personally love the Chroma's EQ section, it's quite strong in its response, so it helps colour sounds to your heart's content. But if you want to try bypassing it to see what effect it has on your output noise, just use one of the four Audio Outputs 0, 1, 2,or 3 instead of the mono output. The EQ only affects the mono output, not the four individual ones. Set your program parameter 5 to 0, 1, 2, or 3 to use the outputs, or use the temporary assign with Set Split 2, Set Split 3, Set Split 4 or Set Split 5 to assign the sound temporarily to outputs 0,1,2,3, respectively.

There's no need at all to have an engineer remove or bypass the EQ circuitry, as you can use the other outputs instead and keep your Chroma as designed. If your EQ section is noisy, do as Jesper says and get the pots cleaned or changed, or the rest of the circuit sorted out by an engineer.

Have you tried the XLR outputs, too, in case you get less noise from them???

By the way, are you certain it's the 3 voice boards that are faulty? Have you tried putting those boards in different slots to be sure they are the culprit? Have you tried cleaning all contacts where the boards plug into the Chroma? Have you tried removing 3 good boards and seeing what effect it has on the 3 bad ones? Try to eliminate other possible sources of failure before you send the 3 boards to Roy for servicing, so you can be sure that you'll be curing the right problem.

I hope this is helpful!

Chris Ryan [21030691] · Wed, 9 Nov 2005 09:41:06 -0800

Fortunately all sounds are on the site, I have syntech interface, logic 4.7, everything hooked up, the syntech in default position. There must be a possibility to let the logic load the chroma through the syntech, never done it.

  1. How to get the logic to load the .sit files?

Logic will not load the .sit files directly. These are StuffIt format compressed files. The patches are also available in other compression formats such as zip and tar.gz. But they will have to be uncompressed first--then you will have access to the sysex (.syx) files contained within the archive files.

Free expanders for StuffIt files are available for Mac OS/Mac OS X and Windows. However, StuffIt is a proprietary file format and there have been some good arguments recently for moving away from it. I assume you're either using Windows or Mac OS X. Zip is the standard compression format on Windows, so I assume there are easy ways to decompress. If you're on OS X, simply opening a .zip or .tar.gz file will automatically decompress it.

You might also find it easier to use a sysex librarian program. See the Mac and Windows editor/librarian pages at the site.

Jesper Ödemark [21010135] · Wed, 9 Nov 2005 18:49:54 +0100

Have you tried the XLR outputs, too, in case you get less noise from them???

_ALL_ synthesizers should have XLR - Amen!

Claes von Heijne[16330008] · Thu, 10 Nov 2005 07:39:40 +0000

Thank you for all help, I will stay away from modding circuitry, go for the original when renovating, I'm happy to hear there are noiceless chromas, then mine could be too.

I have the decompressed factoryprograms, how do I get them into logic and through the syntech?

Claes von Heijne[16330008] · Fri, 11 Nov 2005 17:32:10 +0000

loading sound via sysex

I have the syntech interface (working) a g4 os 9.2.2, logic 4.7 , a yamaha 256 usb/midi box, and the sysex universal librarian. The program loads factorybanks, but the chroma doesn't receive when sysex librarian transmits, midichannels are correct. What is wrong?

Chris Ryan [21030691] · Fri, 11 Nov 2005 09:51:46 -0800

Re: loading sound via sysex

See "Loading and Saving Sounds Via MIDI" in the Syntech manual.

Claes von Heijne[16330008] · Mon, 14 Nov 2005 08:38:44 +0000

Thanks for all help. The sysex librarian works brilliantly with the chroma. What a wealth of sounds to check out!

Lars Johansson [21030632] · Mon, 14 Nov 2005 09:55:29 +0100

Any luck with locating a service tech ?

Jesper Ödemark [21010135] · Mon, 14 Nov 2005 14:43:19 +0100

I know a guy down here (down as in not among the polar bears like LJ and Claes that is ;) ) who has serviced a Chroma recently for another guy. I think I has his number somewhere...

If you don't trust LJ with the cards that is...

electronically yours, jesper - closer to Copenhagen and I'd be danish

Lars Johansson [21030632] · Tue, 15 Nov 2005 00:24:57 +0100

I know a guy down here (down as in not among the polar bears like LJ and Claes that is ;) ) who has serviced a Chroma recently for another guy. I think I has his number somewhere...

Southerners........SIGH.

If you don't trust LJ with the cards that is...

I had to turn down Claes due to too much at work ( and at home ) to complete the mission in a reasonable time window.

electronically yours, jesper - closer to Copenhagen and I'd be danish

What a shame.

Key Commands to set Stereo Out from Mono Out

Uro [21030401] · Wed, 9 Nov 2005 10:12:44 -0800

Can someone post the key commands to set this up?

Chris Ryan [21030691] · Wed, 9 Nov 2005 10:18:32 -0800

See Audio Hookups in the Performance Manual.

Uro [21030401] · Wed, 9 Nov 2005 13:38:54 -0800

thanks!

Internal Connection Question

Tim Siefkes [21030850] · Sat, 12 Nov 2005 08:30:48 -0600

If someone has a Chroma opened up for visual inspection, can someone help me determine the correct way to re-connect one of the internal wires? I disconnected one without paying attention to the correct orientation. (dumb move, I know...)

On the left side of the Chroma as you face the keyboard, directly behind the two Mod levers, is a small circuit board with two transformers. At the front of that is a four-pin connector, and at the rear is a three-pin connector (J27 according to the schematics) that leads to the EQ board. The three wires that connect to this are colored red, orange and brown. What is the correct orientation of this 3-wire J27?

Thanks for any assistance!

David Clarke [21030085++] · Sat, 12 Nov 2005 13:44:10 -0500

Tim - take a peek at the picture/diagram in the post Balanced Output Transformer - Hookup Aid (July 2002).

This should help with the reconnection.

Tim Siefkes [21030850] · Sat, 12 Nov 2005 15:17:30 -0600

That's exactly the diagram I was looking for. Thanks.

Stereo Operation

Brian Silva [21030450++] · Mon, 14 Nov 2005 22:08:40 -0500

I've been trying to run my Chroma in stereo. I used the 2 XLRs, and tried inserting both a stereo and a mono 1/4' plug into output #3. I then linked a program and pressed "Set Split 5". Nothing comes out of the XLR for output 3. Is there a special wiring configuration to a "dummy plug" that enables stereo operation or will any 1/4" mono plug do?

Thanks.

Jack Colburne [21030142+] · Tue, 15 Nov 2005 01:21:10 -0500

I remember that the Chroma came with a Fender dummy plug; I remember the "F" logo on the round end of the plug. I don't think a std mono 1/4 will do it. So, I think you're on the right track, Brian.

(I'm gonna guess... just to see if I'm right. )

I'm not a tech either, but if I got this right, the balanced outputs are fed from the mixer after the returm from the 4 TRS 1/4 "effects loop" jacks. So the dummy plug needs to be physically plugged into 1/4 output #3 to remove the signal from the "mono" out (which will end up at XLR #1) but the audio has to be brought back into the Chroma through the ring of the 1/4 plug to keep the signal in the audio chain (to end up at XLR #2). So, my guess is that it was a regular "closed" dummy from Fender (like used on a Fender gtr amp). (The tip would be connected to the ring.)

OK, tech guys. Let me know if I got this one right! :-)

Brian Silva [21030450++] · Tue, 15 Nov 2005 08:47:47 -0500

Thanks for the effort. I'll try it and let you know.

Greg Montalbano, Analog Synthesizer Service · Tue, 15 Nov 2005 08:01:37 -0800

Hi- I have one of the Fender dummy plugs here, on the back of a Chroma; it's not "closed", just a blank 2-conductor plug with no connections.

Brian Silva [21030450++] · Tue, 15 Nov 2005 12:51:20 -0500

I've tried all types of connections. It just refuses to send anything out of the #3 XLR under any circumstances.

Jack Colburne [21030142+] · Tue, 15 Nov 2005 13:08:41 -0500

Ha! Thanks, that's why I'm not a tech!

... hmmmm... but he's already tried it with an open "mono" cable... if Brian can't get it working with any type of wiring, somethin' else "ain't right"...

Brian Silva [21030450++] · Tue, 15 Nov 2005 15:16:49 -0500

That's correct. I've tried every configuration. Am I missing something or does this Chroma have an issue with the #3 XLR output? If so, what could cause it?

Jack Colburne [21030142+] · Tue, 15 Nov 2005 15:39:27 -0500

Brian,

I just found my own Fender dummy. It is indeed a TS, not TRS plug. I guess that the act of inserting the plug into 1/4in Ch3 must be all it takes to route the linked patch to the Ch3 XLR.

  • Did you verify that the linked patch is coming out of the Ch3 1/4in output for unbalanced "stereo"?
  • As you've been trying different wirings, has the linked patch been present at the "mono" XLR output or is it now missing from the entire mix?

Brian Silva [21030450++] · Tue, 15 Nov 2005 15:57:54 -0500

The linked patch has indeed been mixed in at the mono XLR out. After pressing Setsplit 5, it just disappears. It's possibly rerouted to XLR output #3. There's just nothing coming out of it to find out if that's the case.

Jack Colburne [21030142+] · Tue, 15 Nov 2005 16:16:45 -0500

When you do a SetSplit 5 does the link patch get routed to the unbalanced Output 3?

Brian Silva [21030450++] · Tue, 15 Nov 2005 17:11:04 -0500

I can't tell. It dissappears from the mono mix in the main mono XLR output, but doesn't reappear at XLR output #3

Jack Colburne [21030142+] · Tue, 15 Nov 2005 19:00:43 -0500

Brian and I took it off line for a bit...

Looks like he's doing it exactly as described in the Performance Manual, (with a mono 1/4 plug instead of the dummy). He gets Link Program audio from the 1/4in Ch3 jack when he uses a std 1/4 hook up, but it disappears when he uses the 2nd XLR.

Anybody have any way to easily check if the 2nd XLR is working properly?

David Clarke [21030085++] · Tue, 15 Nov 2005 23:13:43 -0500

It might be worth-while to double check the connections from the transformers for the XLRs.

You could also just try flipping the orientation of the these connectors to see if it 'changes' the behaviour.

Failing that, it would be a matter of tracing the signal through the circuit to see where it 'disappears' (the 2nd XLR out does have its own amplifier, so it is possible that it - or an associated component - could have failed).

Brian Silva [21030450++] · Wed, 16 Nov 2005 08:37:38 -0500

David,

Sorry for the incorrect salutation. Initially I thought that response was from Jack Colburne

Brian Silva [21030450++] · Wed, 16 Nov 2005 08:36:00 -0500

Thanks Jack.

My limited knowledge of electronics will leave me with just checking to see if any of the wires are disconnected. Troubleshooting bad components is above my pay grade.

Olli [21010284] · Fri, 18 Nov 2005 08:55:33 +0100

hi
i'd definetely appreciate how to configure the plug as i have no "dummy". silly question. what does the stereo signal add to the mono signal on the chroma? how is it wired? does it give a real stereo image and how?

Jack Colburne [21030142+] · Fri, 18 Nov 2005 06:35:09 -0500

Hi Olli,

Well...My original guess about wiring the dummy was wrong...but... here's a more thoughful explanation.

Performance Manual: Alternate Audio Hookups

There is no "stereo" signal a such from the Chroma... in the sense that you cannot pan channels or patches in a left-to-right stereo field. You can, however, send a entire program and/or program channel out one of the 4 outputs labelled 0-3 in the back of the Chroma using Parameter 5. The jacks are tip-ring-sleeve jacks and are usually used as effects loops to send the signal from the Chroma and return it back to the mono mix. If you use a tip-sleeve (mono) 1/4in plug in these jacks, the signal assigned to that jack is simply taken out of the mono mix completely and never returned. So, if you use a regular guitar-type 1/4 cable in these outputs it simply removes the sound assigned to that output from the mono mix and you can do with it what you like. If you assign a sound to one of the outputs but don't plug anything at all into the jacks, nothing changes... all the programs simply come out of the mono outputs.

You can also temporarily send the Linked program out one of the outputs by doing a Set Split 2,3,4 or 5 (for outputs 0,1,2, or 3)

Important: There are balanced outputs for only the main mono signal and for output #3.

What Brian is doing is trying to send a Linked program (often the same program as the main program) out Output #3 and hard pan one signal left and the other right. If you use the same program (since the Chroma is a real analog synth... not sampled waveforms) the sound can be rich, awesome, huge, lovely, devastating, ... depending on the Program. :-) You can use the separated programs/channels simply as separate sounds, not panned left-right. and you can use all 4 outputs at the same time by sending the 4 channels (A and B) from two linked programs out different outputs. (It cuts down your polyphony, of course)

The dummy plug in the 1/4in jack simply, by physically plugging it in, removes the sound assigned to that output from the mono mix. He wants to use the XLR balanced outputs in the studio... but cannot get any signal out of the output #3 XLR. His problem seems like it might be with the balanced output... not the dummy plug.

I have since found my original dummy plug but have not checked it for continuity. It is a 1/4in mono plug. There seems to be some confusion over whether the dummy is wired "open" (meaning the tip is not wired internally to the sleeve) or "closed" (tip is soldered internally to the sleeve, sending the signal to ground). I don't think it makes any difference since, as long as the tip signal is being removed from the mono mix and not returned on the ring of a "stereo" plug, it should work. (I think...)

So, to use the XLR outputs as "stereo" outputs, you plug an "empty" 1/4in cable into output #3 and any sound assigned there should show up at the second XLR jack. If you want to try it w/o worrying about the balanced studio outputs, assign a sound to output #3 and just plug a guitar type cable from the 1/4in #3 jack and plug it into your mixer.

I hope that helps some.

Olli [21010284] · Fri, 18 Nov 2005 13:17:08 +0100

perfect! thank you very much jack. i imagine the effect if you link and pan one right and the other left. i have never tried that. its definetely a good idea. maybe i'll be able to demonstrate that at some point in the demos i am doing on bluesynths.com

Greg Montalbano, Analog Synthesizer Service · Fri, 18 Nov 2005 17:06:17 -0800

OK, I've been repairing a Chroma, and finally have it up to working conditon (more on that later); so I tried the "stereo" output feature.

Called up a split patch; pressed Set/Split #5 --- as far as the phone jacks were concerned, the seperate outputs appeared at 0 and 3. Tried it with the XLR connectors: after plugging a dummy into 3, one side of the split was appearing in one of the XLRs, and the other side was appearing in the other XLR. I haven't been able to make BOTH appear in the "3 output" XLR --- but then, I'm not too familiar with this instrument yet. I did find this passage on page 25 of the manual: "Note: to use both XLR output jacks, it is suggested that the Link program be set to Output Select [5], Value 3."

At the risk of asking a stupid question, have you tested your split setup to be sure it's functioning correctly?

I have a question of my own, concerning the voice cards -- this particular unit had 5 nonfunctioning voice cards. Got them to the point where I can go through the initial Tune routine with no error messages; however, some of the voices don't respond the same in some patches (filters, etc), and on rare occasions one of the boards will show up on the error screen upon power-up, only to be missing the next time. Am I correct in assuming that a board can pass the Tune test & still be parially faulty? And are the boards that show up as faulty once in a while normal, or an indication of an intermittent problem? Still so much to learn....

Jack Colburne [21030142+] · Sat, 19 Nov 2005 01:15:00 -0500

Olli,
You're welcome, I hope it made sense.

i imagine the effect if you link and pan one right and the other left.

Yes, it's gorgeous. The phase cancellation from the free running oscillators (even without detuning the programs) give it a spaciousness and natural "in your head" chorus effect that almost all my other gear can't. Part of the beauty of analog. (I don't know enough about modeling synths to know if the oscillators free run out of sync to gain the same effect)

I remember programming a gong for a project that took on a completely different life when I linked it to itself in "stereo". It was absolutely huge... almost surreal. (One of those serendipitous patches... while you are searching for the ultimate electric piano, you accidentally come up with the ultimate 8 foot gong.)

Jack Colburne [21030142+] · Sat, 19 Nov 2005 01:40:58 -0500

To make both programs appear at the XLR output #3, you would use Parameter 5, (Output Select) and assign output #3 to all 4 channels. Set Split #5 temporarily assigns the linked patch (both channels) to output #3. Parameter #5 does it permanently, as part of the program.

To get the "stereo" effect the manual is referring to, you'd take that signal you got from the main XLR and hard pan it to one side of the stereo field and the output from the #3 XLR and hard pan it to the opposite.

Not to speak for Brian, but I know that he tried the 1/4in "stereo" output #1 & #3 set up that you described and it worked... it was that one XLR output that didn't seem to be working.

David Clarke [21030085++] · Sat, 19 Nov 2005 10:27:26 -0500

Jack Colburne wrote:

...I have since found my original dummy plug but have not checked it for continuity. It is a 1/4in mono plug.

I can confirm that the Chroma dummy plug is wired open (i.e., no connection between tip and sleeve).

David Clarke [21030085++] · Sat, 19 Nov 2005 10:33:13 -0500

"Sort of" working voice cards

I have a question of my own, concerning the voice cards -- this particular unit had 5 nonfunctioning voice cards. Got them to the point where I can go through the initial Tune routine with no error messages; however, some of the voices don't respond the same in some patches (filters, etc), ... Am I correct in assuming that a board can pass the Tune test & still be parially faulty?

Yes, you are correct.

There aren't really any 'health checks' included in tuning routine - it simply attempts to determine the proper scaling & offset values for the oscillator & filter. As long as the firmware thinks the tuning values look OK (i.e., not way out of range), then the 'tuning' will pass.

Tuning routing looks at a 'high frequency' and a 'low frequency', and then assumes that the oscillator and filter response is 'linear' between these. If a failure is such so that they're not linear, then variation (badness) will result.

The type of 'patch' chosen can also have an effect.

The tuning routing looks at each channel as a straight VCO/VCF/VCA. When the patch type is changed (e.g., to change the routing), the electrical signals on the voice card are routed to other places. The chips which do this routing can certainly work with one setting, but fail in others. (The tuning routing would not be able to catch this - so tuning could pass, but a particular patch may not work 'right').

One good way to debug a 'different sounding' voice card is, with schematic in hand, follow the active signal path through the voice card, comparing it to a 'good' card. At some point you should see a notably different (or missing) signal on the bad card. This should point you to which components are in need of adjustment/replacement.

... And are the boards that show up as faulty once in a while normal, or an indication of an intermittent problem?

I wouldn't expect it to be 'normal'. It is likely more an indication that a card is just on the edge of the limits of where the tune routine can 'pull it in' or that the parameters on the board are just a little bit out. Depending on whether the card is warm/cold and what voltages it saw at start-up, you may be just inside the limit (i.e., a pass) or just outside the limit (i.e., a fail).

If everything otherwise looks OK on the board, you might want to check out the two Field Change Notices which directly discuss tuning difficulties:

FCN2-001 - To prevent Dual Channel Boards from drifting beyond tuning range after warm up

FCN2-005 - To insure the Dual Channel Boards tune properly during auto tune, and to prevent Dual Channel Boards from drifting beyond normal tuning range.

Of course, before determining if the board are actually ill, the other tune-related items in the system would need to be confirmed OK (e.g., the 5V level from the PSU, the health of the +/- 12v supplies, the DAC null, the pulse width settings on the voice cards, etc.)

(Note: While both of the field change notices refer to a specific set of serial numbers, that would have been based on the parts which were originally in the synths at the time of manufacture. Over time, boards may have been swapped, etc. - so it is best to visually check that the changes are in place for the boards of interest).

Good luck.

Brian Silva [21030450++] · Sat, 19 Nov 2005 10:50:09 -0500

I can confirm that the Chroma dummy plug is wired open (i.e., no connection between tip and sleeve).

Thanks

Jack Colburne [21030142+] · Sat, 19 Nov 2005 14:24:34 -0500

thanks! It seems to be a consensus... it's definite. Open, it is.

Fwd: For Sale: Rhodes Chroma voice board, New Old Stock

Chris Ryan [21030691] · Thu, 24 Nov 2005 18:53:11 -0800

From Analogue Heaven:

Date: Wed, 23 Nov 2005 03:42:15 EST
To: [Analogue Heaven]
From: [e-mail address removed]
Subject: For Sale: Rhodes Chroma voice board, New Old Stock

I have a Rhodes Chroma voice board that I'd like to sell. It's new old stock back from when I was an authorized Rhodes Chroma repair guy. It has never been used or even been plugged into a Chroma. I think I have hung onto it long enough. Price: $150.00 Located in Las Vegas, Nevada.

Getting spare voiceboard, does revision matter?

TB [21030106] · Fri, 25 Nov 2005 22:23:21 +0100

hi guys. new to the list. i havent actually bought a Chroma yet, tho i'm negotiating one right now (waiting for the seller to install "nuclear power")

anyway, i've found a NOS Chroma voiceboard. now, reading info on the Chroma site about different voiceboard revisions, it made me wonder,

does revision matter? can this NOS voiceboard work in my to-be Chroma regardless of revision?

or they need to be exact match?

David Clarke [21030085++] · Fri, 25 Nov 2005 18:20:30 -0500

Tom - for all intents and purposes, any 'working' voice card (old, new, otherwise) should be OK.

Good luck with your purchase-to-be.