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ChromaTalk Archives: July 2015

Re: Tapper/'phantom' button presses

Go to previous messages in thread, June 2015

Greg Montalbano, Analog Synthesizer Service · Fri, 10 Jul 2015 10:39:01 -0700

On 6/5/2015 5:17 PM, John Leimseider wrote:

I have a couple of NOS panels left. They are not perfect cosmetically, but they work perfectly. They are $150 Cdn each plus shipping. The shipping is crazy expensive from Canada, depending on where it's going. If you need one, figure out the shipping method that you prefer.

Hello-

I can definitely use a set of panels -- or at least a working version of the left one.

Trying to restore a seriously neglected Chroma for a customer, but can't really determine the extent of the work needed without a functioning control panel.

Contact me on or off list, and hopefully we can set something up.

Thanks.

~GMM

'Self-playing' patch configuration

David Clarke [21030085++] · Sun, 19 Jul 2015 13:47:28 -0300

As things have been quiet on the Chroma list I thought I'd take a moment to mention something that you might want to play around with. (If you haven't already stumbled across it you might find this a bit interesting.)

It may not have a lot of general utility - but here goes:

Set up a patch (perhaps a scratch patch), then set:

  • Param 46 to 1 (Volume Ampl Mod 1 set to Env 2A)
  • Param 19 to 31 (Env 2 Delay to Retrigger on Sweep A)
  • Param 8 to 0 (Sweep Mode = Async Free Running)

If the keyboard is not at this time already sounding, hit a few keys on the keyboard.

The Chroma should be playing notes by itself - and as you leave them play, how/when the notes will sound will change over time with a beating pattern. If you press other/different keys - then it will be those keys that sound/repeat.

The actual initial patch won't really matter too much. The key here is having the volume modulation set to Env 2 - and then having Env 2 being retriggered by the sweep.

What you'll have is the same sort of behaviour used in some of the 'repeating' factory presets.

The Chroma's concept of a note being 'off' is just that its amplitude has fully squelched. So - in this case, the retriggering of the envelope by the sweep will cause the notes to re-sound forever - but not as a drone (as you might get with infinite sustain) but as retriggered notes (sort of like a sequence).

The Async Free Running sweep mode actually forces the sweep rates for the different channels to run at slightly different rates - so you'll tend to get a beating pattern of the notes after a while.

Give it a try - you might like it.

(If the sweep mode was changed to one of the other modes then you'd actually get all the notes repeatedly playing at once. The total number of remembered 'notes' will depend on how many voices are allocated to the current Chroma instrument).

David Hobson [21030506] · Sun, 19 Jul 2015 15:22:52 -0400

Thanks, David. I enjoy messing around with that 'repeating' configuration.

I was playing around with that type of setup not too long ago and decided to hit the record button for a single track, impromtu solo synthesizer recording.

This is what my patch sounded like in the configuration you mention:

John Hagerty [21030616] · Sun, 19 Jul 2015 19:43:04 +0000

Bravo, Mr. Hobson!! Inspirational! Can't wait til Chroma comes back from the shop to try the Clarke patch setup (Sasdelli PSU upgrade).....Cheers, JH

All cards ERR display and loud droning noise on power up - help!

Howie Shen [21030552] · Wed, 22 Jul 2015 03:45:50 +0000

Hi all,

I hope someone has encountered the following problem and can help:

When I power up my Chroma the display almost immediately reads Err 01234567 and there is a loud, constant blast of noise from the output. The noise is a mix of white noise and what sounds like some digital artifacts, and if I play the keys it seems as though some of the faintly heard pitches within the noise partially track the keyboard but are WAY out of range.

Are there known failure modes that are consistent with these symptoms? I have already tried the obvious reseating of connectors. It seems to me that the Chroma is failing very early in its self-diagnostic boot up cycle, almost as if it doesn't see any channel cards installed. But I don't understand why it then outputs loud droning noise?

Any insights from this community of Chroma experts would be sincerely appreciated!

Much thanks,
Howie

Greg Montalbano, Analog Synthesizer Service · Tue, 21 Jul 2015 21:51:06 -0700

First, try Set Split #31 -- do the voices go through the tune routine?

It is possible for one or more bad voice cards to drone, AND to affect other voice cards. Immediate failure of tune can also point to a problem with the DAC, with the I/O board trimmer, or with the channel mother board. Many possible causes -- if you haven't already, check here: Hardware Fault Diagnosis & Repair.

Paul DeRocco [21030230] · Wed, 22 Jul 2015 00:45:28 -0700

From: Howie Shen

When I power up my Chroma the display almost immediately reads Err 01234567 and there is a loud, constant blast of noise from the output. The noise is a mix of white noise and what sounds like some digital artifacts, and if I play the keys it seems as though some of the faintly heard pitches within the noise partially track the keyboard but are WAY out of range.

I can only guess what it sounds like, but if it's 60 or 120Hz, it could be a bad analog power supply.

Chroma on ebay

Steve Wilson, American Music Center · Thu, 23 Jul 2015 22:13:38 -0700

Hello everyone,

I finished repairing a while back and the owner has decided to part ways with it. he asked if I would make mention of it here.

you can check the auction out at the link below, but I collected the major points below.

  • has cc+ upgrade installed
  • power supply upgrade installed
  • the remaining pc boards have been repaired and are fully functional. the electrolytic capacitors have been replaced, the 4000 series cmos chips have been replaced. we did have some phantom taps from the solenoid tapper occasionally but didn't think it was a big enough deal to investigate since neither of us found the tapper useful anyway.

so here is the link. its up for $5000 obo.

Buddy Casino [21010137] · Fri, 24 Jul 2015 14:45:01 +0200

Where is the link?

Steve Wilson, American Music Center · Sat, 25 Jul 2015 13:56:10 -0700

Sorry, I thought I posted the link, Here it is again: [item #171868312568].

'New' CC+ firmware usage/comments/problems?

David Clarke [21030085++] · Sat, 25 Jul 2015 12:50:04 -0300

The last CC+ firmware release [218] added MIDI sync'able sweeps as well as arbitrary tuning (e.g., microtonal tuning) support from the keyboard.

There hasn't been much/any discussion of these items since released.

As the MIDI sync ability was added at the request of users, has this feature been used by anyone? If so - did it do what you wanted? If not, were problems found?

While arbitrary keyboard tunings aren't something that everyone would necessarily want/need - has anyone experimented with it? Again - any comments, or were any problems encountered?

David Hobson [21030506] · Sat, 25 Jul 2015 14:12:21 -0400

Hello, David.

I have not yet tested the newest firmware since I ordered a few for my Chromas a while back that were not working.

I have yet to purchase an eraser and burner, but when I do the first project will be to upgrade that firmware; then I'll definitely experiment with the new MIDI sync and arbitrary tunings.

I'm surprised everything has been so quiet so far, and there has not been much more talk about the firmware. I'm assuming some Chroma users were finally able to burn their chips?

Jesper Ödemark [21010135] · Sat, 25 Jul 2015 20:34:34 +0200

I haven't made it a priority to upgrade but decided to wait for feedback on the new version... so... feedback please! ;)

Chris Smalt [21010280+] · Sun, 26 Jul 2015 23:30:33 +0200

The last CC+ firmware release added MIDI sync'able sweeps as well as arbitrary tuning (e.g., microtonal tuning) support from the keyboard.

There hasn't been much/any discussion of these items since released.

The first "group burn" of the firmware didn't work out, so I'm hoping for a new initiative from someone to burn EPROMs for us.

David Hobson [21030506] · Mon, 27 Jul 2015 06:00:28 -0400

Well, I'm willing to burn some EPROMs for whoever is interested.

I'd need to leave this offer out there for a bit to see about how many *new* EPROMs I should order. If there is at least some interest I'll be ready to provide pricing and all that. I have two Chromas to test the EPROMs on, so if there is a problem I will know it and be able to communicate that problem to the proper authorities.

I'll probably start a new thread offering my services to the ChromaTalk community. In the mean time anyone may feel free to put their request in.

Ron Joseph [21030042+] · Mon, 27 Jul 2015 06:26:40 -0400

Count me in for a set ! Thank you to everyone making this possible.

Al Tutlys [21030645] · Mon, 27 Jul 2015 07:22:14 -0400

I would be interested. Although well intentioned, that first batch didn't work out for me as well., Al Tutlys

Michael McInnis [21030027] · Mon, 27 Jul 2015 08:01:13 -0400

I would also like a set.

Ian Hamilton [21010150] · Mon, 27 Jul 2015 22:35:42 +1000

I'm in need of two sets... Just let me know how and how much! :)

David Hobson [21030506] · Mon, 27 Jul 2015 09:25:52 -0400

Okay, I suppose we don't need a new thread. I'll need pretty close count though, but it doesn't have to be perfect.

If any of you who read this need EPROMs email me with the number of chips you'll need. I'll take my time to build a list so can order as bulk as possible to save on cost. Remember, not everyone is following this mailing list every day

When I have a list, I'll come up with a reasonable price for the EPROMs, and mailing prices of course.

Please email me at: [address removed]

James Coplin [16330036] · Mon, 27 Jul 2015 09:29:14 -0500

I would want a set for my expander and synth.

microtuning

Frank Bonarrigo · Mon, 27 Jul 2015 09:49:35 -0400

Does the chroma in anyway support alternate tunings?

David Clarke [21030085++] · Mon, 27 Jul 2015 11:04:38 -0300

Frank, yes - if the Chroma in question is fitted with the CC+ and the current version of firmware is used [218 as of the date of the post], then the user can have any arbitrary keyboard tuning they might like.

All CC+ Users: New Firmware EPROMs for Sale.

David Hobson [21030506] · Mon, 27 Jul 2015 17:15:43 -0400

Hello,

As some of you may already know the last group EPROM burn didn't work out for one reason or another.

I've decided to offer my services in order to make the latest features of the new firmware available to anyone who needs them: MIDI sync'able sweeps, and arbitrary/microtonal tuning (thanks to David Clarke [21030085++].)

I'll be ordering new EPROMs which I'll test one of my Chromas to make certain they work.

Please email *directly* (not through ChromaTalk) with the number of programmed EPROMs you will be needing, and where you live. I'll respond with a confirmation.

When I have compiled a list after waiting a few weeks for individuals who don't watch the ChromaTalk mailing list every day, I'll have an idea of what my order looks like and will followup with the cost and my preferred payment method when you EMAIL me at:

[email address removed]

Regards,
~David Hobson.