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ChromaTalk Archives: May 2006

Use of the Pressure Sensor

Chris Ryan [21030691] · Mon, 01 May 2006 08:46:59 -0700

This month's update to the site is original documentation from Fender on how to program for the pressure sensor.

WTB: Parts

Frank Hettlich · Mon, 01 May 2006 18:08:12 +0200

Hi "Chroma" guys,

I am looking for the following parts for one of my beloved Rhodes Chromas:

  • 10 x 1.87K, 1W 3% KRLP T.C. resistor. (Field Change Notice FCN2-005)
  • alternatively: 1 Voice Card at a reasonable price (not $125 and above...)

Anybody has those for sale or does know where to get them?

Best regards

Jesper Ödemark [21010135] · Tue, 02 May 2006 07:14:04 +0200

The resistor value you can combine with a bunch of other resistors if you don't find a match...

Doug Terrebonne [21030114] · Mon, 01 May 2006 23:26:22 -0700

The resistor value you can combine with a bunch of other resistors if you don't find a match...

Not in this case - thats a Tempco resistor...

Jesper Ödemark [21010135] · Tue, 02 May 2006 09:46:16 +0200

Woops - sorry... I should've kept my mouth shut! ;)

David Clarke [21030085++] · Tue, 02 May 2006 20:10:45 -0400

I am looking for the following parts for one of my beloved Rhodes Chromas:

  • 10 x 1.87K, 1W 3% KRLP T.C. resistor. (Field Change Notice FCN2-005)
  • alternatively: 1 Voice Card at a reasonable price (not $125 and above...)

Frank - the last time I looked (a few years ago) the KRLP plastic-coated tempco resistors were tough to find. There were a couple places that still offered them in ones- and twos-, but they weren't cheap (i.e., they were something crazy like $10 ea).

If you do really want/need more than just a couple (e.g., 10), then you're starting to get to magic number where it almost makes more sense to buy a lot of them from KRL/BANTRY directly.

When I bought from them 4 years ago, they had a minimum order of 50 pieces, and then the cost worked out to about $3 ea.

In terms of the replacement voice card, I agree that $125 is more than I'd like to pay - but that does seem to be the going rate these days (when you take into account that the market price for the two CEM chips will probably get you in the neighbourhood of $50 just by themselves, I guess it is understandable why the cards sell for what they do).

Good luck with your repairs,

David

Paul Hackett-Evans [21010094] · Wed, 03 May 2006 02:01:47 +0100

"In terms of the replacement voice card, I agree that $125 is more than I'd like to pay - but that does seem to be the going rate these days"

It's crazy, isn't it - if someone sold all 8 voice cards from their Chroma, they'd net $1000. I've seen complete Chromas sell for less than that. So there's an incentive for the financial profiteer to disassemble a Chroma and sell its parts, one at a time.

That's a terrible thought, isn't it!

Tom Klepacki [21030025] · Tue, 02 May 2006 21:47:50 -0400

Cannibalizing/ selling parts one at a time...? Anybody watching old, even brand new, Fender guitars, on Ebay? Ebayers are dismantling the guit-fiddles and selling the parts. Even brand new (made in Japan) Jazzmasters. The sum of the parts is worth much more than the whole, it seems...

I have a 1962 Jazzmaster neck/ partthat I bought new (I'm dating myself) for $40.00. (It's on a pink tele-style guitar that I built, with a solid oak body (it's for heavy metal!) Since it has little wear on it, as I play keys, I could Ebay the neck, and get maybe $1000.00 for it..

Before you know it, somebody is gonna buy a new Toyota Camry, and sell it piecemeal, on Ebay... Nyuk! (I read somewhere that if a new car that costs, say, $20,000, it would costlike like $150,000 to buy every part, and every sub-assembly, from the parts department.) (Figures are approximate. You actual prices may vary!)

In a way, cannibalizing some of the original Chromas may be a way to actually keep the animals 'pure'...

Jesper Ödemark [21010135] · Wed, 03 May 2006 07:34:06 +0200

Do compare with Oberheim 4-voices or 8-voices... sad story! All the SEMs ripped out and sold one by one.

Doug Terrebonne [21030114] · Wed, 03 May 2006 01:25:56 -0700

That seems to be exactly what the guy who was selling all the Chroma parts recently on ebay was doing... Shame...

Chroma Knob and alternatives

Frank Hettlich · Mon, 01 May 2006 18:17:07 +0200

A friend of mine (Gruezi Hans), who recently bought one of my totally refurbished Rhodes Chromas (looks and works like new now) was asking me if I post the following questions on this mailing list (he fundamentally lacks communicating in english):

  • Is there any chance to buy the Chroma knob described on the rhodeschroma.com website?
  • How about asking all guys on this list if there is a demand which justifies a development?
  • What are the commercial alternatives (Doepfer drehbank etc) which work "like a charm"?

Thanks a lot in advance

Paul Hackett-Evans [21010094] · Mon, 01 May 2006 17:42:31 +0100

Hi Frank,

  • Is there any chance to buy the Chroma knob described on the rhodeschroma.com website?

As far as I know, there's only one of these units in existence. It was hand built by David Clark for his own use and he hasn't shown any signs of manufacturing them.

  • How about asking all guys on this list if there is a demand which justifies a development?

Oh, boy! We all want one! But they'd be costly, and David has a life, too!

  • What are the commercial alternatives (Doepfer drehbank etc) which work "like a charm"?

I use Emagic SoundDiver on the PC, which works very well, but it's software, so there's no knobs, sadly. I don't know if it's possible for one of the many MIDI control surfaces to be set up to edit the Chroma, although I guess it must be possible. I doubt that there is one with enough knobs to make a one-knob-per-function controller, like David's Chromaknob.

Bob Brenenstuhl [21030894] · Mon, 01 May 2006 13:24:44

Actually, wouldn't it be kinda a waste to link any of the parameters involving the tapper to a knob? I've been thinking of this all week, as I've been anticipating getting my Chroma (which I just got last night!) The best thing I could find (please let me know if I'm wrong!) is the M-Audio Axiom 49. I reasize you guys wanted more of a box style interface, but for $250.00, and free shipping from novamusik.com you may not do better. The 61 key version just has more keys and costs more, so that doesn't really help. I'm sure it would take a bit of screwing around with to get it to do what you want, but 9 sliders, and 8 knobs should be about just enough. The knobs are the endless rotary type, so no droppoffs happen when they are first turned, Plus it has "assignable aftertouch", which I'm hoping would trigger the pressure sensitivity on my Chroma. Also weighted keys. I'm sure it feels like a toy compared to the Chroma keys, but being able to use the pressure sensitivity, would be a big plus for me. Also the wheels are assignable, so I'm assuming they could be set to different things then the chroms levers. Check it out and let me know what you think before I possibly waste my money, I'm sure somebody here has tried something like this at some point. Thanx, have a great day!

Paul Hackett-Evans [21010094] · Mon, 01 May 2006 19:04:01 +0100

Actually, wouldn't it be kinda a waste to link any of the parameters involving the tapper to a knob?

You can always disable the tapper if you don't like it! Set Split 9 will do it.

I've used M-Audio gear in the past, it's well-built and has always been very reliable for me. The Axiom looks really good value on the web adverts I've seen, although I've never tried one myself. Is the Axiom polyphonic aftertouch or channel aftertouch? Does this make a difference to you? If aftertouch is important to you, give it a whirl.

Incidentally, I've seen the 61-key version for sale online in the UK for only 10 pounds more than the 49-key one. £210 as opposed to £200 for the 49. If the price differential is that small where you are, it may be worthwhile getting the 61, for a wider playing range.

The big unknown is the feel of the keyboard action. I have no idea what the Axiom is like. Some plastic keyboards are great, but not always - I once tried the E-Mu 'Proteus Keys' - a keyboard version of the Proteus 2000, bought on Ebay. It sounded fab, but the keyboard action was horrible. I sold it on very quickly and got a Proteus module instead. Much nicer played from the Chroma!

I once used a Roland D-50 keyboard, which had a nice action for a plastic keyboard, to play a Chroma through MIDI, but the feel of the Chroma's keyboard action is so unique and so good, that I couldn't use the D-50 without really missing the feel.

I'd agree with you that it's worth using the knobs on the Axiom to edit the Chroma - I always use SoundDiver, to save wear on the Chroma's data slider and membrane switches, but I can't imagine ever wanting to use another keyboard to play the Chroma. Still, if you need aftertouch, it's one way to get it. The Axiom's cheap enough, and M-Audio are reliable, I'd give it a try.

Daniel Benoit [21030109] · Mon, 01 May 2006 20:59:37 -0400

Anyone who would like to add some "pots" and swithes" to a "midi" chroma(or any midi synth) should look at the MIDIBOX (GNU) project

I have tried it, it's cheap, easy and fully "customizable"

you start with a "CORE" (about $23.00)and add the modules that you want.

Say:

  • you want 32 pots, add the AIN module (about 13.00 parts + pcb)(pots not included)
  • you want 32 swtichs and the Din module (about 13.00 Part +pcb)(shtich not included)

I have installed midi/vca automation to a 36 inputs Neotek seriesII mixing board with this systeme and it works...

Go to this www for the real midibox site: http://ucapps.de/

for the pcbs http://www.avishowtech.com/mbhp/buy.html

remember this is a diy project

Jesper Ödemark [21010135] · Tue, 02 May 2006 07:42:03 +0200

Hi Daniel and hi list!

I've been dreaming of this ever since getting Chroma too. I discussed it with David offlist and then the CPU-upgrade project came along and people started talking about better possibilities etc.

I'm a gear-head and a knob twister, not a tech-head and a soldering master though I've both repaired simple faults in some gear and added mods to other.

Today I sequence the Chroma from the Atari 1040 and I can store patches with the Chroma-Editor. But to make new sounds without using the switches and slider of the Chroma I'm forced to click and drag on the Atari and then upload to the Chroma to hear the result. Not practical and just annoying so I've settled on panel programming this far.

So... I want some kind of knob control but since I'm no techie and no midi guru either I'm still hoping someone can guide me through this.

  1. Do I need some upgrade before being able to send CC messages to the Chroma?
  2. Can I just add a programmable knob box between the Atari out and the Chroma in (via the EES interface)?
  3. Is the mentioned midibox a messy project? I'll gladly solder and solder and solder, but surface mounted stuff and pic-programming etc is beyond my skills.
  4. What's the approximate cost of all components and hardware if I want knobs for all things in the Chroma?

Please, please, please... can someone explain to this stupid (at least technically) swede how to solve his problem? ;)

Bob Brenenstuhl [21030894] · Thu, 04 May 2006 23:13:58 -0400

I just meant that using a knob for parameters that use the tapper is a waste of a knob, since they are menu type items. You wouldn't be able to feel the tapper if you were turning a knob on another keyboard anyways.You might be able to hear it, but it depends how loud you play I guess. How many parameters REALLY need tweaking?(non- menu items)

Bob Brenenstuhl [21030894] · Sat, 06 May 2006 11:07:37 -0400

Incidentally, I've seen the 61-key version for sale online in the UK for only 10 pounds more than the 49-key one. £210 as opposed to £200 for the 49. If the price differential is that small where you are, it may be worthwhile getting the 61, for a wider playing range.

The prices I've seen are $250.00 U.S. for the 49 key, and $299.00 for the 61 key. Based on the number of keys vs- the price, I was going to go for the 49 key version, then I noticed something that changed my mind. On the 61 key version there's a space to the right of the knobs you can rest your hand if your going to be fiddling around with the last two knobs to the right. You might have to look at the photos to see what I mean. It looks much more comfortable to me. It seems like everything is crammed in on the panel of the 49 key version, so I'm going the extra mile and getting the 61. I just have to make sure that the keyboard will run on an adapter. I had an m-audio radium 49 and that did, so hopefully this one will too. I refuse to have to turn on my laptop just to jam out. I'll definetly let everyone know what I think of it. Hopefully "fully programmable aftertouch" equals "Chroma aftertouch"! Have a good one!

Frank Hettlich · Sat, 6 May 2006 19:40:13 +0200

Thanks to all who replied to my questions regarding a knob box for the Chroma!

I am really surprised that there aren't solutions available (used by list members) which offer 50 knobs/sliders for all the Chroma parameters as the "Chroma knob" does...

The M-Audio looks nice but it does not fullfil what my friend and I am looking for: - a keyboardless (because the Chroma does have a VERY nice keyboard as we all know) at least 50 Knob/slider box.

How about the Novation Remote SL product line? They even seem to release a non keyboard version with ONLY knobs, sliders and a nice display called ReMOTE ZeRO SL AND you have that "auto map" function!

Rob Vandivier [21030396] · Sat, 6 May 2006 14:36:57 -0400

how about the Roland PG1000? anyone try that yet?

David Clarke [21030085++] · Sat, 06 May 2006 11:34:09 -0400

How Many Sliders

... How many parameters REALLY need tweaking? (non- menu items)

I think the number of useful knobs really depends on how you want to use them.

I do agree that in a performance/on-the-fly environment, you'd probably only want a couple.

That being said, when you're sitting down and try to find a 'new sound', I really do like the ability to quickly try any/all of the possible changes.

CPU board

Olli [21010284] · Sat, 6 May 2006 23:53:41 +0200

hi

sorry for what might be a stupid question but i havnt been able to follow closely what has been going on here for a cpl of weeks so i was wondering where stands the new CPU board project.

thanks

btw what price was envisaged for the board?

David Clarke [21030085++] · Sun, 07 May 2006 15:21:21 -0400

Olli - the list is currently waiting for Sandro [21010294] and I to post the details in terms of price and ordering specifics.

Murray Macdonald [21030276+] · Mon, 8 May 2006 13:09:25 -0700

Is there software available for this CPU board that adds MIDI, or is this just a true CPU replacement?

David Clarke [21030085++] · Mon, 08 May 2006 19:02:12 -0400

Murray - we're talking about the Chroma CPU Plus (CC+) and so it a true CPU replacement that in summary:
  • adds native MIDI support, with CCs for all the parameters
  • adds another 150 patch locations (4 banks x 50 ea. total)
  • takes the batteries away
  • cuts down on power draw
  • adds a 'voice watch' mode
  • adds the ability to turn on/turn off local control

Jesper Ödemark [21010135] · Tue, 9 May 2006 06:48:13 +0200

But we're still waiting for some input into pricing, if it's ready for shipping etc. And I wonder which midi control box to buy or build...

When will you build a copy of the pressure sensitivity board? ;)

Bob Brenenstuhl [21030894] · Tue, 09 May 2006 02:08:32 -0400

Yeah, wouldn't it be nice if every part of the Chroma were availabe for sale, kind of like parts for a Jeep? So many more of them would pop out of the closet if that were the case. You can't have too many good sounds!

Jesper Ödemark [21010135] · Tue, 9 May 2006 09:03:15 +0200

???

I was only talking about this new CPU-board, not spare parts for older Chromas etc. Correct me if I misinterpreted you...

Bob Brenenstuhl [21030894] · Tue, 09 May 2006 04:39:05 -0400

I'm sure three's a Chroma waiting someplace that will come back to life when it gets it's new CPU-board. Also, I want a pressure sensitivity board if anyone starts making them ;D

Jesper Ödemark [21010135] · Wed, 10 May 2006 07:09:27 +0200

OK, now I get it... :)

Chroma Sound Set 6

See also Patch Tape on eBay: Factory Sets 4, 5, and ... 6?, April 2006

Jesper Ödemark [21010135] · Mon, 8 May 2006 18:05:52 +0200

Hi list!

The NOS cassettes I recently won on Ebay [see thread Patch Tape on eBay: Factory Sets 4, 5, and ... 6?, April 2006] arrived today. I haven't tried loading them yet and won't have the time this week, but I can confirm that there are six sound sets included on these cassettes...

I'll get back if I find anything unusual on them...

David Clarke [21030085++] · Tue, 09 May 2006 22:00:54 -0400

Factory Set 6

There has recently been some discussion about a 6th 'factory patch set' on cassette.

In looking at some other items this evening, I remembered that the sysex patches on the site (specifically, the Chroma Cult ones found on the Patch Downloads page) also list a "FS6."

I can confirm that their FS1-FS5 of that archive correspond to the 5 factory sets we're familiar with - so I'd hazard a guess that the FS6 file contains the contents of the 6th set that is on cassette.

Chris Ryan [21030691] · Tue, 9 May 2006 19:55:23 -0700

Chroma Cult Patches

I've never been certain that the Chroma Cult banks on the site actually correspond to those sent out by Ken Ypparila [21030229] in the 1980s. I can't remember where they came from, but they seem to correspond fairly closely to the sets available from the Music Machines site, though the archive on the site is comprised of 42 sets to their 46. Was anyone besides me a member of Chroma Cult and still has the Apple II floppy?

Uro [21030401] · Tue, 9 May 2006 21:29:36 -0700

Re: Chroma Cult Patches

Eventually, if someone is able to upload the FS6 patches to the URL, would any user be able to load all six banks, only FS2-6, or some other combination other than all 6?

Chris Ryan [21030691] · Tue, 9 May 2006 23:40:19 -0700

Re: Chroma Cult Patches

David was pointing out that the Chroma Cult patch sets contain a file called "Chroma Cult FS 06.syx" which may be a sixth set of factory patches. Jesper said he'd let us know what he finds on the cassette he won in the eBay auction; Jesper, perhaps you could compare the two sets?

Yes, you can load any banks you like from the site. The easiest way is to use a sysex program and a Syntech/Chroma Cult MIDI interface. However, you could also use David's patch conversion tools to convert the Syntech sysex files to audio (for use with the cassette interface), textual parameter listings, or the sysex format supported by the EES MIDI retrofit.

Jesper Ödemark [21010135] · Wed, 10 May 2006 08:51:15 +0200

Re: Chroma Cult Patches

My plan is to convert everything on the site into sysex for my EES. But is it possible to just dump that onto a disc and then load that into the Atari? messy way to go but my studio is PC (and Mac) free...

When that is done I'll gladly compare and if there is something unheard of on that second tape I won I'll let you know and might even be able to convert it to some useful format...

See sound set 6, July 2006.

chroma polaris membrane switches

wasteking · Tue, 09 May 2006 07:06:20 -0400

does anyone have used or replacement parts for sale that can save my chroma polaris ? the right hand panel is a mess.

Murray Macdonald [21030276+] · Tue, 9 May 2006 15:17:37 -0700

You can sometimes fix these with silver conductive ink. It's the membrane tail that often cracks where it is bent. (bad design) They get brittle and crack. I have fixed two by peeling them back and connecting to the old trace with conductive ink. DO NOT SOLDER IT! Good luck.

Jesper Ödemark [21010135] · Wed, 10 May 2006 07:27:32 +0200

There is a fender spare parts guy on ebay right now... I bought the factory cassettes from him and he had tonnes of other stuff including polaris spares - check with him...

Chroma MIDI anomaly

Greg Montalbano, Analog Synthesizer Service · Fri, 12 May 2006 10:30:01 -0700

I've recently come across an unusual anomaly using a ChromaCult/KMX type MIDI interface, and was wondering if anyone else had witnessed the same problem.

I've been working on two Chromas; when the interface is plugged into the first, it correctly registers program change commands via MIDI. However, the second unit will change the programs as requested, but the change won't be indicated on the Chroma display (even though the display works when programs are changed via the front panel buttons).

Otherwise, both Chromas function correctly with the MIDI interface (no latch-ups or other problems); both are later serial numbers.

Anyone ever seen this?

Thanks.

David Clarke [21030085++] · Fri, 12 May 2006 22:48:29 -0400

My best guess is that the "MIDI Omni Mode" setting (Set Split-46, P2) may be set differently on the two machines, and that the different behaviour is actually 'expected' based on the different settings.

In particular, if Omni mode is 'on', then chaning programs via MIDI will change the front-panel settings on the Chroma itself, but if Omni mode is 'off', then changing programs via MIDI will change the sound being played - but the front-panel settings on the Chroma will not appear to change.

Does that seem to jive with what is being seen there?

Greg Montalbano, Analog Synthesizer Service · Fri, 12 May 2006 20:27:14 -0700

Hi David --

Nope, it responds (or actually doesn't respond) the same way in Omni On or Off. It's starting to look like some subtle logic problem -- will get out the scope & try to track it down.

David Clarke [21030085++] · Sat, 13 May 2006 08:59:57 -0400

A few quick questions:

  1. Are all 16 parameters for the KMX interface the same on both keyboards?
  2. Are both keyboards running the same version of firmware, and if so - which version?

Greg Montalbano, Analog Synthesizer Service · Sat, 13 May 2006 11:07:00 -0700

Are all 16 parameters for the KMX interface the same on both keyboards?

I believe they were -- I no longer have the working unit here.

Are both keyboards running the same version of firmware, and if so - which version?

Both the same -- rev 14.

I'll experiment more with different settings & let you know if I find anything.

Using the Chroma with a modular synthesizer

Bob Brenenstuhl [21030894] · Fri, 12 May 2006 15:20:49 -0400

Hi there. I was wondering if anyone has ever tried this before. I have a Roland system 100 and expander 102 semi-modular system, and I was thinking of hooking the lfo up to one of the pedal inputs on the Chroma. Has anyone tried anything like this before? I only have the dual piano type footswitch for my Chroma, so I have both volume type pedal inputs free. Does the pedal meant for those plugs have a ring, and tip, or is it a regular guitar cord? Any other ideas would be greatly appreciated also. Thanx for your help, given the value of the Chroma, I didn't want to just run in there with my pants down.(though that's what I would usually do)

Chris Ryan [21030691] · Fri, 12 May 2006 13:09:44 -0700

The Specifications section of the Performance Manual includes this information: Ground on sleeve/Signal on tip. 120K ohms pull up to +12V. 0V to 5V effective input voltage.

Bob Brenenstuhl [21030894] · Fri, 12 May 2006 16:29:00 -0400

Do you think using a regular guitar type plug without the ground would cause a problem? Would not having a ground just possibly make the signal dirty, or could it actually damage something? Other then that it seems it would work, and seems like it would be a ton of fun. I would normally just hook it up and see what happens, but it seems like the Chroma is a little fragile, and I just didn't want to take any chances, plus I figured somebody must be doing something pretty similar to this, and might have some ideas also.

Power supply repair

Kevin Kelley [21030491+] · Sat, 13 May 2006 13:06:16 -0700

It appears that I have been unsuccessful at repairing my power supply for my Chroma. I was wondering if anyone on the list was familiar with repairing the power supplies on the chroma. I would be willing to pay for the repair and the shipping costs if anyone can help. Please let me know if anyone is interested in this repair or maybe you know of a shop that does a good job on this sort of repair?

Greg Montalbano, Analog Synthesizer Service · Sat, 13 May 2006 18:32:23 -0700

What particular problems are you having with the supply? The diagnosis/repair page on the Chroma site has some useful info on checking transistors, balancing the +/- 12 volt supplies, etc.

Sometimes the supplies are too far gone to be worth repairing -- replacement can be easier & less expensive.

AOL and ChromaTalk

Chris Ryan [21030691] · Fri, 19 May 2006 23:00:32 -0700

Due to some overzealous spam protection on AOL's part, at least some of the messages sent to aol.com addresses have been bouncing from the new list (this happened with the synthcom list as well). I tried contacting AOL, but gave up after 20 minutes on hold. I'm not sure that this problem, if it does go away, will not return. If you can, I'd recommend using a non-aol.com e-mail address for your list subscription. Of course I'm not sure that this message will get through to aol.com addresses. I tried e-mailing the affected subscribers directly from three additional mail servers, and all were rejected. I will add a notice to the ChromaTalk subscription page.

Fwd: FS Rhodes Chroma chromacult midi-interface

Chris Ryan [21030691] · Wed, 24 May 2006 19:09:37 -0700

From Analogue Heaven:

From: Jeffrey Koepper [21030671]
Subject: FS Rhodes Chroma chromacult midi-interface-125$/Eps 4x expander 45$

HI I am selling a mint condition chroma cult midi interface for 125$