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ChromaTalk Archives: May 2011

Computer Board on eBay

Chris Ryan [21030691] · Mon, 2 May 2011 17:05:41 -0700

Item #160582232599, USD$229.00, ends May 12. "It has been tested and it works fine. Ideal as a for those with a broken CPU board or just as a spare."

Picture from the auction:

Chris Ryan [21030691] · Sat, 21 May 2011 12:54:21 -0700

Sold for USD$229.00.

Luca Sasdelli [21010226] · Sat, 21 May 2011 22:44:35 +0200

"Amateurs never sleeps"

Chris Ryan [21030691] · Sat, 21 May 2011 13:55:54 -0700

Not sure what you mean.

Luca Sasdelli [21010226] · Sat, 21 May 2011 23:01:19 +0200

Uh... simply I mean this could be bought by an amateur; CC+ a bit more cost and totally different matter. It was a citation from "Rust Never Sleeps" by (Canadian!) Neil Young.

Chris Ryan [21030691] · Sat, 21 May 2011 14:06:03 -0700

Uh... simply I mean this could be bought by an amateur; CC+ a bit more cost and totally different matter.

Oh, right—good point.

It was a citation from "Rust Never Sleeps" by (Canadian!) Neil Young.

Great album. I should dig it out ... but Neil hasn't lived here for decades.

Polaris Problems

James Dugas · Wed, 4 May 2011 04:16:22 -0400

thanks,computer screwy.What I need is green wire ribbon from top to bottom board or fix from busted polaris.JUST wiring.Also,could use program tape once i rewire this baby.AM original owner from1983 till now.Pro musician till2006.Got hurt.Polaris was controller for big gigs.till lightning struck my front yard,blew thru mysurgeprotect.and i then slowlylost sound programs over next few days.saw melted green wire ,got mad.and found nobody inmy town.who could fix.(early2005).replaced with spare yamaha till i had to quit playing(burned hand).can play again now after 5 years therapy ,but miss polaris power.mypolaris never gliched till that nite.still looks great,all lightlswitches lite,have power cord and foot switches.Hate it,but am willing totrade my rare excellent working Farfisa Matador suitcase organ,i played as hippie from 1969 till 2005(acidrockdays!)it put me thru college.Matador still is in tune,has trilegs,pedal,suitcase(broke zipper).And Makes Great Cheezy 70"s organ sounds.Like The loads of records it was used on.Check Web site.miss POLARIS that bad .Won't sell but would trade for working polaris.Too old and too fat to lug super heavy Farfisa anyplace.Polaris is lite,compared to That organ.Anyhow,I am Jim Dugas,And am New too this website,phone is [removed] please call if possible about any stuff inthis email.Typing sucks like my computer.U May not get this email...its that bad !Justcall after 8 pm est.Typing this took an hour.thank You guys.Hope U get This letter.My 1st and maybe last.bye

Next CC+ Batch Order Planning

David Clarke [21030085++] · Thu, 05 May 2011 20:29:49 -0400

Following up to the April 9th note on the Chroma mailing list ("Advance Planning for Next CC+ Batch"), we have once again placed enough people on the CC+ wait list to justify another build of boards.

We propose to accept orders for this next build up until end of day Sunday, May 15th.

To ensure a timely order of parts for those who have requested CC+ boards, we would like to coordinate receipt of payment by Sunday, May 22nd.

As of this writing, each of those people believed to currently be on the wait list will have been separately contacted via e-mail (to see if they're still interested - and if so, to confirm their order.)

If you're not currently on the wait list - but would like to have a board from this build - please be sure to let me know before May 16th.

If you believe you're on the wait list but have not recently received an e-mail from me to confirm, please let me know.

Once again, thank you for your continued interest and participation with the CC+.

Patrik Gudmundsäter [21010240] · Wed, 11 May 2011 16:18:12 +0200

Want one CC+!!

Chroma going up for sale soon

Thomas Story [21030352] · Sun, 8 May 2011 14:07:25 -0700

Well, I think I'm going to be putting my Chroma up for sale soon. Before I list it on eBay I thought I'd check here and see if anyone, or anyone you know is looking for a Chroma.

Works great, has always been serviced by Greg here in California.

Really the only thing left to do on it is refinish the wood. I'll be taking some pictures later today if anyone is interested.

I'm not a professional musician, it's time to let it go to someone who will hopefully put it to better use than just as a master controller (as great as it is for that!).

Thomas Story [21030352] · Mon, 9 May 2011 19:58:01 -0700

Well, a chapter has come to an end

I vacillated for along time over selling the Chroma, but as of today it will be heading to a new owner. Sad as I am, I'm happy it will be going to someone who will appreciate it as much as I have. I know I will more than likely never have another one, but circumstances both financially and professionally have dictated that I let go. I'n definitely better at collecting synths than letting go of them!

So, advice for packing and shipping. My thoughts are -

  • 2" bubble wrap on the ends to act as sort of "foam" end caps like in new electronics purchases
  • inserted into 1st cardboard box - foam board strips hot glued to the box which will then slip into an outer box, making sure that the corners have plenty of protection.
  • reinforced cutouts on the end of the boxes for places to carry, necessary?
  • Pedals, interface and manuals boxed up and shipped separately .

I'm concerned about the keys bouncing around, maybe a foam board cut to fit under the keys on the ends to keep them from moving up and down?

And and all advice is appreciated, the last thing I want is to have anything happen to this beautiful synth! It will be fully insured if course.

Going to miss this amazing support group for an amazing instrument!

Device panel for Cubase

Rob Belcher [16330123] · Mon, 09 May 2011 10:50:25 +0100

Hi there Chroma fans, Can someone help me out with the Cubase device panel for the Chroma? I've installed it, but when i open it inside Cubase i just get a blank screen without all those lovely sliders... Can't wait to get this working!

Enabler Production Run

Randel Osborne [21030467] · Mon, 9 May 2011 09:40:35 -0400

Hello-

I'm writing to let you know that I'm accepting orders for a production run of Enablers - my 96 knob physical controller for the CC+ equipped Rhodes Chroma.

Photos and video:

The price is $2,600 US, plus shipping, and orders will require an $800 US deposit. I anticipate a production time of approximately 6 months from the receipt of a deposit to the shipment of your Enabler.

Because each Enabler is hand crafted, there are a few opportunities for customization - I'm currently making the outer case from Bubinga for a customer, and I can vary the dimensions and finish of the case to attempt to match those of your Chroma. Also, I can customize the startup screen to display (nearly) any text that you wish.

Also, because each Enabler is hand crafted, there might be slight imperfections and variations in the casework, and in the operating system code; currently the LCD can become unresponsive after many hours of continuous use, but it's operation is restored after a power cycle.

Shipping and insurance is expensive. I'll work with domestic and international customers to determine the best way to get your Enabler to you.

If you're interested, please let me know, and send a deposit via PayPal.

I'm always happy to answer questions.

Marais · Mon, 9 May 2011 10:20:36 -0400

Just chiming in to add that Randel does fantastic hand build work on the Enabler and was great to work with. He even went out of his way to try and match my finish on my Chroma from pictures and was very successful. The Enabler brings out life from the Chroma that we didn't even know it had. Hope to see some other Enablers in the world soon. I hope to have a Enabled Chroma patch bank to share with the group by summer.

M - proud owner of Enabler #02

Fwd: I will sell one of my two Chromas the SN°21010228

Chris Ryan [21030691] · Mon, 9 May 2011 22:49:33 -0700

Begin forwarded message:

I'm on the point to sell one of the 2 my beloved Rhodes Chroma the SN°21010228 under good conditions and fully repaired calibrated and upgraded with new power supply kit, Polyphonic Aftertouch board and CPU Plus (CC+) with the last eprom and display 4x20 from Luca Sasdelli [21010226] well know fine expert of the Chroma and designer of the power supply kit. Located in Italy. Rome. I will ship worlwide. I ask 3000 euro plus shipping. Any info at [email address removed].

Confused about chroma architecture/function...

RJ Krohn [21030455] · Thu, 12 May 2011 13:43:17 -0700

hi all, so now that my chroma is A) up and running, and B) easily programmable, i've been exploring the instrument. having a blast-the polyphonic ring mod capabilities are really cool. but i've got a question...

certain patches in my chroma will exhibit a behavior, and i can't for the life of me tell if it's a function of the patch, or a machine error. on a few patches, if i depress and sustain 3 notes, they will all be in tune. as soon as i depress a 4th note or more, it will cause detuning in the chord to the point that its atonal. it sounds like an out of tune synth. if i release those notes, its back to normal. could this be one of the keyboard algorithms or something, or a fault?

Paul DeRocco [21030230] · Thu, 12 May 2011 15:43:55 -0700

Sounds like a fault to me. The first thing I'd look at is the analog power supplies, to see if they're being yanked around by something. I'd look around the Channel Motherboard, and around the DAC circuit on the I/O Board.

Chris Smalt [21010280+] · Fri, 13 May 2011 01:43:41 +0200

if i depress and sustain 3 notes, they will all be in tune. as soon as i depress a 4th note or more, it will cause detuning in the chord to the point that its atonal.

What is the filter resonance set to for these patches? Some Chroma factory patches are based on tuned resonating filters, with the resonance all the way to 7 and the keyboard used as a modulator. So the tone you hear is created by the filter, not by the oscillator. Maybe some filters don't tune right, or the harmonics are really weird so you get beating between them as you add notes.

I've heard croaky out of tune filters a couple of times, and could always solve it with snake oil ( = reseating the voice boards)

John Leimseider [21030434++] · Fri, 13 May 2011 08:52:36 -0600

Hi RJ, I just thought about a repair I did last month… One of the voice boards didn't have the sync working because of a broken transistor lead… On the programs calling for sync, the bad card had the oscillator that should have been synced, and was detuned to get the proper timbre, just sounding out of tune, instead. See if the bad voice sounds bad only on a sync patch…

Wanted: Chroma

Andrew Kirkby · Sat, 14 May 2011 16:18:31 +1000

Hello all,

Since the purchase of a Chroma fell through, i am keen to buy one and thought that the mailing list would be a good place to start looking for one.

I'd prefer to buy one in unrestored (even broken) condition as long as it is complete.

If anyone has one, please let me know.

David Hobson [21030506] · Mon, 16 May 2011 12:34:03 -0500

Hello Andrew,

I happen to have a broken Chroma that I am willing to sell. Originally I was going to use the voice cards to swap with my working Chroma, but more recently I have been thinking on just selling it.

I would probably be asking 1800.00 usd for this Chroma plus shipping (I would prefer a pickup though, but am willing to ship.) Let me know if you have any questions and I will try to answer them.

Chroma for sale

John Shipley [21030689] · Sat, 14 May 2011 12:51:38 -0700

I am considering selling my old friend. It has been a wonderful keyboard that has been on a lot of jobs with me. I bought it new in Las Veags in 1982. It is in almost perfect working condition. There is one note where the contact is broken and the MIDI interface, from ChromaCult, sometimes doesn't act right sometimes. I just reboot it and it works fine for a while. I haven't had it on for more than an hour at a time for the past few years but I can dump sysex files back and forth from my computer and it records fine. I have all three pedals and an extra sustain pedal that I have used for spare parts. I still have the anvil case that it came in and would ship it in that. Where ever it goes the shipping will be high. I also have all the original manuals and cassettes of the factory sounds. I can send photos [see registry entry for photos] if anyones is interested. Make me an offer.

Manuals on eBay

Chris Ryan [21030691] · Sat, 14 May 2011 14:59:16 -0700

Item #180667009760, current bid UAD$30.00, ends May 24. Programming Manual, Performance Manual, and "engineering updates for interfacing with an Apple II." This could be Appendix O from the Sequencer Manual, Hardware Description and Specifications; I've asked the seller.

Picture from the auction:

Chris Ryan [21030691] · Tue, 24 May 2011 22:30:38 -0700

Sold for AUD$30.00. I did hear back from the seller, and I was right about Appendix O: "Yeah it's mostly from the sequencer manual REV 5 January 24 1984.There's also 2 schematics COMP/CHROMA INTERFACE (Drawing # 30-45587 6/21/82) & PC CHROMA/COMPUTER INTERFACE (Drawing # 30-77241 10/6/82) Also included is a 4 page review from April '83 E&MM "Playing the Rhodes Chroma with the Apple II Sequencer."

Chroma 21040003 (Briefly) For Sale on eBay

Chris Ryan [21030691] · Wed, 18 May 2011 17:52:13 -0700

Item #160589806496, ended by the seller. Was AUD$5,500.00 or "buy it now" of AUD$7,000.00. Not much info on this on in the registry (see 21040003); was owned at least last year by Greg Hutchings of Hutchings Keyboards. "100% functional, refinished wood parts, new power supply and CC+ computer board with midi interface. Recently serviced by Hutchings keyboards the Chroma Specialists and the original distribution and service centre for them in Australia. Included is original performance manual and midi interface. Only thing is one discolored key but I hear this is fixable."

calibrating levers? (also, an interesting tidbit on the pitch wobble thing)

RJ Krohn [21030455] · Wed, 18 May 2011 18:41:33 -0700

hi all, so i have noticed that the zero point of lever 1 is not at its resting point. lever 2 is calibrated perfectly. i'm assuming there's a way to calibrate the levers, but when i look in the assembly, i don't see a trim pot, and skimming thru the calibration procedure, i see nothing related to it. is it possible?

also, just to pass the piece of info along, i found the source of my weird pitch modulation issue, where any more than 3 depressed keys at once would cause certain patches to go completely out of tune. if the pitch modulation on these patches is set to #15, pressure threshold i believe, it causes this. not sure why, as my machine doesn't have the pressure board installed.....strange.

anyway, thanks for any tips on the levers.

Chris Borman [21030194+] · Wed, 18 May 2011 23:08:40 -0400

The ADC without a pressure sensor installed will resolve some value. I recall this has been mentioned on Chromatalk.

Paul DeRocco [21030230] · Thu, 19 May 2011 09:54:00 -0700

hi all, so i have noticed that the zero point of lever 1 is not at its resting point. lever 2 is calibrated perfectly. i'm assuming there's a way to calibrate the levers, but when i look in the assembly, i don't see a trim pot, and skimming thru the calibration procedure, i see nothing related to it. is it possible?

The levers are designed so that there is sufficient overtravel that they always go from min to max--that's why there's a significant dead zone at each end. On power-up, their positions are read, and used as the zero reference from then on. If you hold a lever off-center while you power-up, you'll have this problem. If you're having this problem without holding the lever off-center, it probably means that the lever handle has slipped on the pot shaft to a point beyond what the software is willing to believe is the center. Loosen the set screw on the handle, turn the pot shaft until the pot is putting out about 2.5V, and retighten.

also, just to pass the piece of info along, i found the source of my weird pitch modulation issue, where any more than 3 depressed keys at once would cause certain patches to go completely out of tune. if the pitch modulation on these patches is set to #15, pressure threshold i believe, it causes this. not sure why, as my machine doesn't have the pressure board installed.....strange.

The pressure input to the A/D converter is a floating high-impedance input if you don't have the pressure sensor installed. The A/D converter only reads the keys that are assigned to channels, so the more channels are playing sounds that use pressure, the more times in a processing cycle the A/D input will be connected to the floating pressure line. I can easily imagine capacitive coupling developing a small DC level on this line when this happens. Solution: poke a piece of wire into J22 between pins 6 and 9. Or, just Don't Do That.

RJ Krohn [21030455] · Thu, 19 May 2011 15:43:51 -0700

thanks! yes, got them calibrated re: the below tips. like an idiot, my hand slipped while i was adjusting the nut with the machine on, and bridged two of the pins on the pot, causing a spark and rebooting the machine. lucky i didn't fry anything! whew...

Chris Smalt [21010280+] · Fri, 27 May 2011 22:16:26 +0200

The levers are designed so that there is sufficient overtravel that they always go from min to max--that's why there's a significant dead zone at each end. On power-up, their positions are read, and used as the zero reference from then on. If you hold a lever off-center while you power-up, you'll have this problem.

On one of my Chromas, depending on whether I let it go from above or below, the "pitch" lever doesn't return to the exact same position. With bend ranges of two semitones it's not much of a problem, but when it's an octave or so, the keyboard is seriously sharp or flat. I adapted to it by always doing a quick pull after any push.

Paul DeRocco [21030230] · Fri, 27 May 2011 19:16:34 -0700

There's some dead zone in the software, so that suggests that there's some excess mechanical friction. As I recall, the leaf springs pop out pretty easily, so you might wipe them off, and then grease them with a little Vaseline or something.

various problems with my chroma

Norman Fay · Thu, 19 May 2011 10:35:15 +0100

Hello all, my Chroma has various problems, which are a bit baffling:

For a while, it would work OK, but if left on for some time, all of the boards would fail to tune.

After a couple of months like this, it just failed to tune totally. However, the MIDI out would work OK

then, it would fail to tune AND the MIDI out didn't work. All of the panel lights work OK, abnd it saves/retrieves programs OK too.

I opened it up this weekend, and by swapping voice boards around, learned this:

One of the voice boards, when you plug it in, causes the instrument to fail in the way mentioned above - tune shows all boards at fault, no sound, no midi.

another of the voice boards, when it is plugged in makes a constant whiny sound

The other six voice boards tune up OK

Slot 0 on the motherboard does not work - any voice board plugged into this will fail its tuning routine.

I ran the instrument as a six-voice for a while, it was nice to hear it again! - then it failed again.

The instrument now will not produce either sound or MIDI output, when the tuning button or set split 50 is/are pressed, it shows several voices as failing the tuning routine - each time I press do this, it typically shows different boards at fault, only the 2 empty slods come us consistently, as one might expect. The instument has the CC+ fitted, and also a slight variant of Don Tillman's power supply upgrade, which was fitted by Tony Allgood a few years ago, since which time the instrument has worked great until now.

The 2 dud boards I'm going to change the 3 logic chips on, as per the fault diagnosis page on the chroma website, then try to trace the fault if that doesn't fix it. I also intend to open the instrument up again at the weekend and carry out some of the tests listed on the fault diagnosis page, and see if the voltages etc all measure up OK. In the meantime, does any of this sound familiar to board users who have repaired their instruments?

Luca Sasdelli [21010226] · Thu, 19 May 2011 12:09:45 +0200

Hi Norman,

I suggest trying to gradually isolate the faults.

First of all the motherboard: please check if any bent pin on voice board connectors is visible and, if found any, reseat them. To re-solder motherboard connectors could be a nice idea too.

If all voice board connectors are ok, the motherboard has some fault in it and it should be debugged first:

  • check S&H decoder latch outputs (Z8)
  • check their decoder also (Z1, Z2, Z7)
  • check all channel decoders (Z10, Z11, Z12, Z13)
  • check their data strobe decoder (Z4, Z5, Z7, Z9)

CPS Update

Chris Borman [21030194+] · Sat, 21 May 2011 20:25:14 -0400

CPS production run #5 winding down. All PCB's are built, awaiting final assembly, test and ship. I have a couple extra so if no further takers, I am going to put the remainder on Ebay to hit that bigger audience. I think RhodesChroma only has 150 or so members. Suprising given the estimated 1500+ Chromas in existence! I just want to unload what's left. I do plan to update the webpage to reflect the Rev 2 hardware and installation. I will include the Cadstar Eagle Schematic and PCB files for completeness and repeatability.

Anyway, Hope you folks that have installed CPS kits are happy with the added performance!

Luca Sasdelli [21010226] · Sun, 22 May 2011 09:52:13 +0200

Hi Chris,

surely your kit is a huge improvement to the Chroma; I've installed three of them as an easy job. I've got only one issue: it has been happened only once, but the adhesive pad did detach from the PCB on bass keyboard side, so the PCB was hanging and touching the keys. I suggest to extend the PCB about 1cm extra per side, to allow a hole for securing the edge with a screw to the wood. The centre part is always held by the encoder PCB, so there is no need for further mods.

Chris Borman [21030194+] · Sun, 22 May 2011 07:41:22 -0400

There was one sensor array delamination issue that I heard about at the PCB/wood backing support layer. I use 3M 77 Spray adhesive there and simply did not apply enough in that instance. The issue was resolved in the field by re-gluing with a generic non-conductive adhesive available from your local hardware store.

In your case was it a similar failure or just the bottom Felt Pad layer? If just the Felt pad, then a thin layer of flexible or silicone based adhesive would repair that.

There are 6 .063" holes spaced about the sensor array PCBs between the sensor circuits that could be used for a mechanical attachment. They do not extend through the other layers. See attached drawing.

Jesper Ödemark [21010135] · Sun, 22 May 2011 23:16:44 +0200

surely your kit is a huge improvement to the Chroma; I've installed three of them as an easy job. I've got only one issue: it has been happened only once, but the adhesive pad did detach from the PCB on bass keyboard side, so the PCB was hanging and touching the keys. I suggest to extend the PCB about 1cm extra per side, to allow a hole for securing the edge with a screw to the wood. The centre part is always held by the encoder PCB, so there is no need for further mods.

I experienced the same with my set but that was solved with glue. :)

The kit is great Chris, I think we all agree on that. On other pages and lists people add sync, an extra LFO or similar minor mods on their synths. Here pro-kits with brand new CPU-design, drop-in replacement of PSU and new designed aftertouch are offered. What's not to like?

*looking forward to my vacation and more hardcore action with girl no. 21010135*

Luca Sasdelli [21010226] · Sun, 22 May 2011 23:44:04 +0200

Il 22/05/2011 23:16, jesper ha scritto:

I experienced the same with my set but that was solved with glue. :)

Hi Jesper and Chris,

surely good glue could solve this issue, but I feel more safe by using those holes kindly highlighted by Chris Borman, to firmly hold the PCB with a few small screws.

The Chroma inside is warm, so I don't trust glue that much... :)

Jesper Ödemark [21010135] · Sun, 22 May 2011 23:49:53 +0200

The Chroma inside is warm, so I don't trust glue that much... :)

Glue was quicker. I'll turn (pun intended) to screws next time if it'll come loose again.

"Interconnect Board" on eBay

Chris Ryan [21030691] · Wed, 25 May 2011 18:12:03 -0700

Item #300561152460, starting bid USD$40.00 or "buy it now" for $150.00, no bids yet, ends May 30. No description, but there is a picture. I'm guessing based on the schematic that this is a Channel Mother Board?

David Clarke [21030085++] · Wed, 25 May 2011 21:24:35 -0400

... I'm guessing based on the schematic that this is a Channel Mother Board...

Correct - that's what it is.

The wooden blocks to hold the voice boards upright on the motherboard are shown in the picture too.

Jesper Ödemark [21010135] · Thu, 26 May 2011 11:18:39 +0200

JL Cooper interface [item #120727793106] (78 euros) and original Chroma product leaflet [item #230625294538] (10 euros) on german ebay now.

Pictures from the auctions:

The maniac selling the TBS interface is not giving up either: [item #350016598934] (399 euros).

Chris Ryan [21030691] · Thu, 26 May 2011 21:27:57 -0700

ChromaFace and Brochure on German eBay

On 26/05/2011, at 2:18 AM, jesper wrote:

JL Cooper interface and original Chroma product leaflet on german ebay now.

This was for sale last month; see midi interface on ebay.de. Interestingly, it seems to have a differently shaped enclosure from those shown at the site: see JLCooper ChromaFace.

The maniac selling the TBS interface is not givning up either (399 euros).

Previously listed:

  • €399,00 - May 2009;
  • €399,00 - September 2009;
  • €359,10 - February 2010;
  • €399,00 - May 2010;
  • €399,00 - February 2011.