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ChromaTalk Archives: June 2013

eBay items

Chris Ryan [21030691]

A few current auctions:

MIDI Interface: Item #171050683734 (eBay Germany), starting bid €50,00, no bids yet, ends June 11. I've never seen a MIDI interface that looks like this. Is it a home-made or modified Syntech? The description says, roughly translated, 'The manufacturer is unknown to me.'

eBay171050683734a

eBay171050683734b

CPU Boards: Item #171050664062 (eBay Germany), starting bid €20,00, no bids yet, ends June 11 (same seller as above). Google Translate tells me that the description says in part, "In the second CPU board (RC), however, lacks an EPROM (D0). CPU board of the expander is fully. Software version: last current [looks to be rev 14]."

eBay171050664062

Syntech MIDI Interface: Item #330934204933, ends June 5, starting bid USD$169.00 or price of $299.00. Appears to be a re-post of the one for sale in April for USD$565.00. From the description: "I have drastically reduced the sale price of this item. ... I no longer have any user manuals for these."

Factory Sound Data Interface Cassette: Item #121119673210, starting bid €6,90, ends June 10. A web translation suggests the sounds are actually on CD in mp3 format "without the extra options"—could we get a German speaker to give us a better approximation?

Chris Ryan [21030691]

On 2013-06-03, at 8:08 PM, Chris Ryan wrote:

Syntech MIDI Interface: Item #330934204933, ends June 5, starting bid USD$169.00 or price of $299.00. Appears to be a re-post of the one for sale in April for USD$565.00. From the description: "I have drastically reduced the sale price of this item. ... I no longer have any user manuals for these."

Sold for USD$159.00.

Jesper Ödemark [21010135]

CPU cards - ebay Germany

Item #171050664062

"aufgrund der Umrüstung meines Rhodes Chroma und meines Rhodes Chroma Expanders habe ich zwei CPU-Boards abzugeben. Für alle, die Ersatzteile benötigen. Beim zweiten CPU-Board (RC) fehlt allerdings ein EPROM (D0) CPU-Board des Expanders ist vollständig Software-Version: letzte aktuelle

beide funktionierten bis zum Ausbau (vom Techniker) einwandfrei.

wie immer, keine Garantie, keine Gewährleistung, keine Rücknahme"

Chris Ryan [21030691]

On 2013-06-03, at 8:08 PM, Chris Ryan wrote:

CPU Boards: Item #171050664062 (eBay Germany), starting bid €20,00, no bids yet, ends June 11 (same seller as above). Google Translate tells me that the description says in part, "In the second CPU board (RC), however, lacks an EPROM (D0). CPU board of the expander is fully. Software version: last current [looks to be rev 14]."

Sold for €47,50.

Mailing List is Moving

Chris Ryan [21030691]

I'm moving the mailing list. It may be down for a couple of days—hopefully not long. I will re-subscribe everyone at the new location.

Jesper Ödemark [21010135]

As long as you don't let the foam rot take us... ;)

Michael Zacherl [21030253]

too late! :-(

Chris Ryan [21030691]

The list should now be moved and all members re-subscribed. Please remember to use the new address for posts.

Michael Zacherl [21030253]

cool! thanks Ryan! [Later corrected via personal email!]

Chris Ryan [21030691]

Just a reminder to use the new list: recent posts have been sent to the old one, and it will be shut down soon.

No output on mono outs (blown resistor) and general tuning/beating question

Matt V [21030757]

Hi all,

Just got a chroma (with all upgrades, 21030757) that was working until I got it home and now I have a couple questions:

Mono output problem: I was plugging in the synth for the first time, and as I connected an audio cable to the high output jack, I got a spark. It turns out the grounding cable had become disconnected. The visible damage is a blown resistor on the low output jack, but nothing else. Audibly, I only get grunge from the mono outputs and zero signal. I DO get a signal from the individual audio outs on the other hand, so the problem seems confined to the mono output circuits.

Replacing the resistor is the first step, but it seems unlikely that this would be the only culprit. Following the P27 cable back into the unit, it leads to a transformer. Could anything else have become damaged that I can test for?

Tuning: autotuning works as it should, but even with trimming of the R1 and R2 trimmers on each oscillator to concert pitch, I ultimately end up with a few voices that end up exhibiting much more beating that the others (giving the sense of being "out of tune"). Autotune cannot correct this beating and it's not specific to any one or two voices (that I can tell). Ditto for the filters. Some lock perfectly, others are "just out", to the point that, when self-oscillating, they are pretty discordant.

What is the expected tuning accuracy on units with the new PSU/CC+, etc.? I wasn't expecting digital-esque accuracy, but the drift I'm experiencing is audible enough to be annoying.

thanks!

Paul DeRocco [21030230]

From: M V

Mono output problem: I was plugging in the synth for the first time, and as I connected an audio cable to the high output jack, I got a spark. It turns out the grounding cable had become disconnected. The visible damage is a blown resistor on the low output jack, but nothing else. Audibly, I only get grunge from the mono outputs and zero signal. I DO get a signal from the individual audio outs on the other hand, so the problem seems confined to the mono output circuits.

Replacing the resistor is the first step, but it seems unlikely that this would be the only culprit. Following the P27 cable back into the unit, it leads to a transformer. Could anything else have become damaged that I can test for?

If the resistor on the low level mono out blew out, why are you following the balanced output back through the transformer? The mono out comes from J19-1 on the output board, which comes from the tone control circuit.

If you got a spark big enough to blow out a resistor, you must have hit it with AC line. Rather than try to figure out what _would_ blow out, you should measure voltages and see what looks wrong. If J19-1 isn't sitting near zero volts, then the op-amp is probably blown.

Tuning: autotuning works as it should, but even with trimming of the R1 and R2 trimmers on each oscillator to concert pitch, I ultimately end up with a few voices that end up exhibiting much more beating that the others (giving the sense of being "out of tune"). Autotune cannot correct this beating and it's not specific to any one or two voices (that I can tell). Ditto for the filters. Some lock perfectly, others are "just out", to the point that, when self-oscillating, they are pretty discordant.

What is the expected tuning accuracy on units with the new PSU/CC+, etc.? I wasn't expecting digital-esque accuracy, but the drift I'm experiencing is audible enough to be annoying.

The tuning accuracy is unaffected by the PSU (unless it's flakey), and completely unaffected by the CC+, since the same DAC is still used. The Chroma was never a tightly tuned instrument, and self-oscillating filters are even worse. One thing that often happens to old Chroma filters, which eventually causes them to stop oscillating entirely, so may degrade their tuning linearity before that point is reached, is that capacitors C13 and C14 dry out. If you have a particularly bad board, you could try replacing them, and see if it improves it. If it does, you could replace them in the other boards. But it still won't be really accurate tuning.

Oh, and R1 and R2 aren't for adjusting the tuning, they're for adjusting the pulse width, since the auto-tune doesn't correct that.

Matt V [21030757]

EQ board output issue follow-up

Hi all,

Following up a previous post where I shorted the EQ board with a spark. At the time, the individual outputs worked, but not the main 1/4" or XLR (all I got was staticy sporadic noise).

Since then, the following has been done on the EQ board:

  • replace burnt resistor
  • replace adjacent ceramic cap that had burnt resistor on it
  • replace/socket adjacent IC
  • replace all electrolytic caps

I have not yet replaced the burnt resistor on the main "low" output jack and all that comes out of the main outs is still just distorted, sporadic noise and zero signal.

So my question is:

  1. could this burnt resistor on the jack be the culprit, or should something else be checked? I somehow find it unlikely that a burnt resistor on the one jack would keep the others from working, but what do I know.
  2. since I need to replace the resistor regardless, what is the resistor value over the low-output jack? (I could not decipher from the schematics)

Paul DeRocco [21030230]

Re: EQ board output issue follow-up

From: M V

Following up a previous post where I shorted the EQ board with a spark. At the time, the individual outputs worked, but not the main 1/4" or XLR (all I got was staticy sporadic noise).

Since then, the following has been done on the EQ board:

  • replace burnt resistor
  • replace adjacent ceramic cap that had burnt resistor on it
  • replace/socket adjacent IC
  • replace all electrolytic caps

Which IC? Z5 or Z6? If you only replaced one, maybe the other one is bad.

I have not yet replaced the burnt resistor on the main "low" output jack and all that comes out of the main outs is still just distorted, sporadic noise and zero signal.

So my question is:

  1. could this burnt resistor on the jack be the culprit, or should something else be checked? I somehow find it unlikely that a burnt resistor on the one jack would keep the others from working, but what do I know.

Yes, it's unlikely.

  1. since I need to replace the resistor regardless, what is the resistor value over the low-output jack? (I could not decipher from the schematics)

R2 between the two jacks is 5.6K, R1 across the low output jack is 680.

Questions: Do you get sound from the XLR 3 OUTPUT if you set the Output Select parameter to 3? Is there any substantial DC offset on the outputs of the op-amps Z5-1 and Z5-7? Can you pick up any signal at the drain of Q1? You could do this last test this by chopping the plug off an old audio cable, or unscrewing the plug shell if you have an all-metal plug, connecting the shield to a convenient ground with an alligator clip test lead, and then using the center conductor as an audio probe.

David Clarke [21030085++]

Re: EQ board output issue follow-up

... At the time, the individual outputs worked, but not the main 1/4" or XLR...

Does this accurately reflect the current operational status?

If so - then with reference to the EQ Board Schematic and Assembly, you should simply be able to follow the signal with an oscilloscope and and see where it 'disappears'.

For instance - if the individual outputs work then you should see signal coming in to Q1. Does it exit Q1? If so, does it make it to pin 1 of Z5A? What about to Z5B pin 7.

If you see a signal at Z5B pin 7, but nothing on the output - then perhaps worry about the components on the backplane. If the signal is missing before then, it becomes a matter of working backwards to see where it goes away - and then to determine 'why'.

  1. since I need to replace the resistor regardless, what is the resistor value over the low-output jack? (I could not decipher from the schematics)

A high quality scan showing the backplane schematic is here: Interconnection Diagram 2

As depicted, that's a 680 ohm resistor across the low output tip/sleeve and a 5.6k resistor to the main output signal.

Matt V [21030757]

Re: EQ board output issue follow-up

Hi Dave,

Thanks for the input. No signal on the main outs is still the current situation.

I am WS (without scope, or at least a working one anyway) and may have to have this looked at by someone else with a Chroma.

Is anyone on the list in the US technically and willing to take on this job?

In the meantime, is there any reason that a burnt resistor on the low-output would somehow affect the rest of the main outputs?

Matt

Doug Terrebonne [21030114]

Re: EQ board output issue follow-up

I actually have an EQ board that supposedly works although I haven't tried it. Do you know if your CEM3360s are good?

Go to next message in thread, July 2013

Merging MIDI OUT ports

Eric W. Mattei [21030443+]

Hello All

First, many thanks to Chris Ryan [21030691] for moving the list. Where would we be without him?

I want to merge the MIDI OUT from my Chroma and Expander. Both have the CC+ with the MIDI interconnection kit. I'm considering the MIDI Solutions Merger, 2 in, 1 out MIDI merger. Any suggestions?

Finally, the MIDI Solutions Merger requires "MIDI-power". Does the CC+ MIDI OUT have that? I guess this is a question for David Clarke [21030085++]. BTW, the CC+ kits were very easy to install. Good show!

Thanks in advance
Eric

David Clarke [21030085++]

I want to merge the MIDI OUT from my Chroma and Expander.

Eric - what sort of data are you looking to have the Expander 'transmit' over the MIDI interface? (Just program change data, etc.?)

... I'm considering the MIDI Solutions Merger, 2 in, 1 out MIDI merger. Any suggestions?

I've been quite happy with MIDI solutions gear (I find it to be quite good value for the price).

I've used their 2 in, 1 out merger (it was that unit that is used in the setups shown here: BCR2000 Setup)

Finally, the MIDI Solutions Merger requires "MIDI-power". Does the CC+ MIDI OUT have that?

From what I understand, the MIDI solutions devices don't look for any specific 'power' connection (say, like phantom power for microphones, etc.).

Instead, they essentially 'steal' power from the MIDI signal lines themselves. So, you should only need to have a live MIDI IN port connected to the unit, and it will derive its power from the standard MIDI lines.

... the CC+ kits were very easy to install.

Glad to hear the install went well. Thank you for the feedback.

Best regards,

David Clarke

Eric W. Mattei [21030443+]

Hi David

Re: "what sort of data are you looking to have the Expander 'transmit' over the MIDI interface? "

SysEx. I want to send SysEx from the Expander (not to mention the Chroma) to my interface's MIDI in. For my purposes, I could get away with swapping plugs, but it's nice where everything's all plugged in.

Re: "...MIDI solutions devices don't look for any specific 'power' connection..."

Re-reading the spec, I see that's what they mean. Never mind. :)

Thanks - Eric

Chroma in Italy

Jesper Ödemark [21010135]

Item #290928500876

" RHODES CHROMA SYNTHESIZER ---NEU CPU PLUS --NEU PSU --- CC+MIDI -original flightcase--top zustand ohne Garantie und ruckgabe ,,,,"

Hans Wurrrst

does anyone now this seller' hes got quite a lot of interesting vintage gear for sale... thanks kris

Luca Sasdelli [21010226]

Unfortunately, never heard him before.

Jesper Ödemark [21010135]

I've often seen his not seldom overpriced gear. He likes to drop one instrument at a time at Ebay and hope or contact off Ebay. That's what I've come to learn...

Hans Wurrrst

yes, hes also announcing in the German area, ive seen hes ads fo a couples of years now. i thought maybe one of our Italian fellows might know him...

Are there any ex-ARP folks on this list?

Christopher Winkels

If so, would you be so kind as to drop me a line? I'm currently in the research phase of a project pertaining to ARP and also its Chroma spinoff. Even if you had a relatively junior or short-term position with the company I'd still be interested in your recollections.

Front panel sliders

Ian Hamilton [21010150]

Hi,

The sliders on my Chroma(s) are quite stiff and feel grungey so I'm keen to replace them with new parts. I've scanned the documentation and know the values, but could anyone point me in the right direction for a model and possible suppliers?

I haven't received any messages since the board changed over ... hope this gets through ok.

Cheers, Ian.

Johnny Vintage [21010244]

Why not desolder, open, clean and relube ?

They work like new after that.

Paul DeRocco [21030230]

From: Ian Hamilton

The sliders on my Chroma(s) are quite stiff and feel grungey so I'm keen to replace them with new parts. Ive scanned the documentation and know the values, but could anyone point me in the right direction for a model and possible suppliers?

I've never found exact replacements anywhere. They were custom made at the time. Same for the Polaris. For my Digital Chroma project, I found some nice sliders, but I did new boards, and the sliders aren't mounting compatible with the old ones. I second Johnny V's suggestion.

Luca Sasdelli [21010226]

I already did the slider repair as described, and it was excellent.

Philippe [21010227]

Which lube did you or Johnny use ?

Luca Sasdelli [21010226]

The lube is only for the metallic moving parts, therefore a generic silicon-based lube for fine mechanics should be okay.

The resistive pad and the sliding contact should be only cleaned and not greased.

Philippe [21010227]

OK thanks.

part value check---> c9 on EQ board?

Ben Vehorn [21030757]

Hi all,

I'm fixing an EQ board for which the 1/4" mono out was blown from a loose ground when plugging in (see msg from a week or so ago).

The 100R resistor was blown and blackened the ceramic capacitor at c9, so I figured I'd replace that too in case it was damaged. I can't read the number on the front as it's totally black, but the schematics list it as "10p 10%" and is the same value as the other ceramics at c5-c8. However, the parts in c5-c8 say "10K" on them so I just wanted to confirm that the value should actually be 10 picofarad... or am I reading this incorrectly? The parts list section of the service manual doesn't list these FWIW.

I'm also thinking of changing the electrolytics while I'm in there and wanted to confirm that the "NP" portion of c20 and c21 "CAP ELECT NP 10UF 16V +50-10%" stands for non-polarized... correct? The caps on the board look like they confirm this but wanted to double-check as I've never seen a non-polarized electrolytic cap before.

Obviously I'm going to replace Z5 as well for good measure.

Thanks,
Ben

Paul DeRocco [21030230]

From: Ben Vehorn

I'm fixing an EQ board for which the 1/4" mono out was blown from a loose ground when plugging in (see msg from a week or so ago).

The 100R resistor was blown and blackened the ceramic capacitor at c9, so I figured I'd replace that too in case it was damaged. I can't read the number on the front as it's totally black, but the schematics list it as "10p 10%" and is the same value as the other ceramics at c5-c8. However, the parts in c5-c8 say "10K" on them so I just wanted to confirm that the value should actually be 10 picofarad... or am I reading this incorrectly? The parts list section of the service manual doesn't list these FWIW.

Yes, it's 10pF. There's really no such thing as a 10K capacitor.

I'm also thinking of changing the electrolytics while I'm in there and wanted to confirm that the "NP" portion of c20 and c21 "CAP ELECT NP 10UF 16V +50-10%" stands for non-polarized... correct? The caps on the board look like they confirm this but wanted to double-check as I've never seen a non-polarized electrolytic cap before.

Yes, they're nonpolar, and they're not that uncommon in audio applications. In a pinch, you could replace each one with a back-to-back series pair of 22uF caps, but if you're buying parts, you might as well get the right ones.

Obviously I'm going to replace Z5 as well for good measure.

You might put in a somewhat better op-amp while you're at it, like an NE5532, or a TL072. Might reduce the noise a smidgin. And it's a good idea, whenever you replace an IC, to put in a socket, in case you need to change it again.

Luca Sasdelli [21010226]

I agree with Paul, but about the OA replacement, I've got some experience:

  • NE5532s are likely to self-oscillate; they needs to have a couple of 10nF capacitors (one between +V and GND and one between -V and GND) directly soldered on track side, just below the IC (or socket), to keep connections as short as possible
  • OPA2134a are the choice as good-sounding OAs, but the instrument "character" tends to become a bit more aggressive, sharper and with improved overall definition; it is just a matter of personal taste, but be aware that the Chroma, once replaced CMB and EQ OAs with these "audiophile" chips, will result in a different own sound

For the above reasons, the use of good quality IC sockets is highly recommended and it allows easy experiment with different OAs without damaging the boards.

Cheers
Luca

Ben Vehorn [21030757]

Thanks guys, I'm socketing the chips for sure but am going to stick to original specs and let him decide if he wants to try something different.

Everything is as I suspected but wanted to double check before ordering.

CC+ Firmware 217 Feature Usage?

David Clarke [21030085++]

The 217 version of CC+ firmware was released last October.

There were few comments or questions about the firmware at the time.

Out of curiosity, is anyone using any of the features added in that release?

(e.g., support for the SparkFun controller, Auto-tune failure details, MIDI velocity maps, auto-display of knob box data via the serial display, auto-send of data back to knob/slider/editor upon program change, etc.)

Jesper Ödemark [21010135]

Not yet, though I plan to add a display sometime in the near future.

Luca Sasdelli [21010226]

Hi Dave,

I've installed 217 on my Chroma and another one here for repair; I've used the auto-tune failure display with great ease on the second Chroma, due to some cards to be fixed. Really a great feature!

Since long time I've got a SparkFun controller + parallel display and I'll install them together with my BCR2000 as soon as I'll find the right time to do it (I'll try to reproduce the Chromatrol II), so that I'll provide some usage details about.

John Leimseider [21030434++]

I got the display, but I still need the connector. Do you have the part number for it? I definitely want to use the failure details and the display of knob box data.

David Clarke [21030085++]

...I got the display, but I still need the connector. Do you have the part number for it?

John - if you're using the rear-panel CC+ cable, then it's just extra pins on a DB-15.

If you're looking for the connector that will mate directly with the CC+ (e.g., connect directly vs. using a CC+ cable set), then these are listed in the drawings here: The Chroma CPU Plus (CC+): Installation Instructions - Wiring Diagrams for Internal and External Cables.

The 6-pin connector to mate with the display signals on the CC+ are AMP/Tyco P/N 103957-5 - which you can get from Digikey as P/N A28407-ND.

Marais

Not much of a DIY'er but if someone were to make up a nice display for purchase I would be interested to complement my Ipad and BCR.

August B. Raring [21010148]

The "Auto-tune failure details" are very helpful! Thank you David!

August

Memory extension

Mirko Lüthge [21010245+]

Hi,

with reference to the described memory extension (1600 sounds). Would it be possible to control the selection of bank & sounds with a software update or only by external switches ?

Mirko

Michael Röpsch [21030816]

Hi Mirko,

this was an old projekt for the original CPU board (still working). On the old CPU board there aren't five bit left to control the extra space of SRAM, so the original Chroma hardware isn't able to perform switching 32 banks. First you would have to get deep in modifying hardware and second you'll have to to write your own software upgrade for this: In times of CPU PLUS (CC+) with better MIDI my Memory Extension Board makes no sense.

I only wrote this article (The 1600 pr...), because Chris Ryan [21030691] asked me for - it's a historical curiosity - nearly 20 years old!

Greetings to your Chroma!

Michael

Mirko Lüthge [21010245+]

Hi Michael,

thanks for the info, nevertheless nice idea.

Greetings from my RC & RCE

Mirko

registration + problem...

Sam Shepherd [21010117]

Hi there, bought 21010117 from Tony Miln. new PSU & CPU fitted by James Walker of Synth Repair Services UK. I just added Chris Borman's amazing poly aftertouch.

this is where my problems begin.... when starting up, I get Err 27, (which i understand means voice cards 2 & 7 arn't working) then i started getting Err 2567 and now Err 01234567 any ideas?! or have i just fried all my voice cards :( ..cant seem to find any clues on the diagnosis pages... a few times the voices wouldn't load and it just made weird noises...

Thanks! whilst it was working, it was a dream...

Sam

Dryden Chambers

try reseating and then moving your voice boards around. m

Al Tutlys [21030645]

I remember reading that with a new PSU, it is crucial to be sure the + and - voltages are precisely recalibrated. If not, cards get shut down.

Sam Shepherd [21010117]

Ah, is it possible that this may also cause the chroma to restart from time to time?

Because that's happening also!

Thanks

Sam

Paul DeRocco [21030230]

Any time that many things go wrong, suspect the power supply first.

Lawrence Eldridge [21010100]

Interesting, also have my Rhodes Chroma in for repair with James Walker at the moment with the PSU and CPU mods - he got back a few months ago describing the same problem, but I haven't heard back since which leads me to suspect the problem is still there.

Luca sent the following good advice, which if possible I'd suggest following:

did you engineer recalibrate the instrument as recommended in Switching Power Supply Unit Replacement Kit ?

In synthesis (and in sequence):

  1. adjust +5V analog for exactly 5.05V
  2. adjust I/O board offset to minimum (the only one timmer on the board: DC millivoltmeter on the close test points)
  3. patch with pulse wave and width set to 32: adjust each VCO trimmer to gain 50% duty cycle

All the best,
Lawrence Eldridge

David Clarke [21030085++]

... Any time that many things go wrong, suspect the power supply first.

I'll certainly support Paul's suggestion.

The first, easiest step will be to use a multimeter and see if the right voltages are coming from the power supply itself. The voltages can be measured by poking the meter probe into the back-side of the connectors on the power supply itself.

(If it is Luca's power supply which is installed in the unit, then the connectors are still generally in the location shown in the original Service Manual entry. If it is some other model of supply that has been installed - then you can still go by the colour code of the power supply connector wires. As well, if it is some other model of supply, then the details of the supply can be shared with the group so we can better understand what it is/what it's characteristics are).

If the voltages seen at the power supply don't look good, then that will be something to be investigated and fixed before going further.

Perhaps even before the power supply measurement would be to do a quick inspection of the physical state inside. You'll want to make sure that the power supply cables are securely inserted - both at the power supply side, as well as at the destination side. You'd also want to make sure that all other cables are attached and not loose/dangling (especially relevant if the unit was shipped to you).

A few other questions which might shed some light on the behaviour:

  • is the Err 01234567 behaviour now seen on every boot, or just some/most?
  • when the Err 01234567 indication occurs on power-up, does anything change when you perform a [set-split][50]?
  • when the Chroma 'restarts' - does this happen all by itself (e.g., you're not necessarily doing anything - a spontaneous reset) - or does it seem to occur just when certain operations are performed (e.g., just pressed a button, etc.)?

David Clarke

Go to next message in thread, July 2013

Syntech MIDI Interface on eBay

Chris Ryan [21030691]

Item #181163064573, USD$200.00 or starting bid of $100.00, no bids yet, ends June 29. "This midi interface for the rhodes chroma is 100% functional."

eBay181163064573

Sold for USD$100.00.

New to list

Michael McInnis

Hello All,

My name is Michael McInnis and I am in Portland, Maine USA. I just put a deposit on a Chroma...haven't yet seen it or checked it out, but I am looking forward to having the instrument in a week or two after its been serviced.

I am told it is 21030027 and I will be interested to see if it has Arp boards in it and if any upgrades have been done. I see no history of this instrument in the registry.

It is missing it's case, but isn't suffering from foam rot damage so I guess that's good overall, especially since it will be a studio instrument. It does have the pedals, however.

I will be installing the CC+ & power supply upgrades.

I was looking at the EQ upgrade board and thought how cool it would be to put Korg PS-3100 style resonators there. I am not a tech, so it would have to be DISE (do it somebody else).

Anyhow, glad to "meet" all of you and I will be sure to keep you updated on my instrument's progress.

Regards.

MM

Chroma kind of power spiking ?

Matt Hillier [21010094+]

Hi guys

chroma expander here seems to be creating this audible power / spike effect .....the actual screen / chroma doesnt turn on and off but the audio out is sending what sounds like some kind of quite loud click / clonk at times.Should i record it for upload ? not sure why i think its a power issue but has its intermittent to a degree and seems to get worse and then becomes almost constant as the chroma warms up.

many thanks for any advice

uk techs

Matt Hillier [21010094+]

Hi

can anyone recommend a uk tech for chroma psu upgrade etc ? seems james walker who i used for other things is super busy and always nice to get someone recommended.

matt

Chris Ryan [21030691]

Have a look at Service Centres: UK on the site.