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ChromaTalk Archives: April 2008

Syntech/Chroma Cult/KMX Schematics and Source Code

Chris Ryan [21030691]

Ken Ypparila has kindly contributed the schematics and hex source for the Syntech (AKA Chroma Cult, AKA KMX) MIDI Retrofit.

NOS Cheek Blocks Back on eBay

Chris Ryan [21030691]

Item #150232833129, starting bid $10, no bids yet, ends April 10. The seller (musicpartsguru) currently has the AC sockets back for auction as well [see NOS Cheek Blocks and Footswitch on eBay, March 2008, for a picture].

time for the new PSU?

Jesper Ödemark [21010135]

My Chroma has a funny low-pitched noise+hum going and now often refuses to tune any voices. I guess I should take this as a hint to install the new PSU. :S

Anyone here who can confirm this episode before their Chroma PSU went dead?

Jesper Ödemark [21010135]

thanks list, for the mental support! :D

Chroma 21010135 reporting back for duty...

New PSU installed, without tapper voltage and with shorter mounting screws, but up and running.

I just hooked it up in its natural environment: [studio pic] and just getting it there was more fun than usual - my back doesn't hurt!

All the midi hooked up now and both in and out works perfectly too. I was too superstitious to shout "yes" before having tested that. The best thing of all is that what I intended with the whole switch did work - all voice boards tune now. So it was the old PSU starting to give up on me so I wasn't taking the plunge a day too soon...

Good work Luca, and thanks for bearing with my annoying cries for help the other night!

It was almost hard to put back the lid on the girl after having checked her out, cause I had to unhook the headphones and I had already got into the sonically wonderful world of the Chroma again.

Luca Sasdelli [21010226]

Re: thanks list, for the mental support! :D

Hi Jesper and all,

glad to read this :-)

Tomorrow I'll send you a mail bag with new resistor and 22mm screws; the 7W resistor will already have an insulating Sterling sleeve on properly bent terminals.

Please check carefully the +5V analog supply, because it's a reference on DAC (I/O board) and therefore responsible for auto-tuning: the voltage between the regulator heatsink (output) and ground must read 5.05V.

The SPSU embedded +5V trimmer should be not touched, because it's related to the digital line.

Thank you very much for the feedback!

Jesper Ödemark [21010135]

Re: thanks list, for the mental support! :D

Luca Sasdelli skrev:

Hi Jesper and all, glad to read this :-)

Glad to write it. :D

Tomorrow I'll send you a mail bag with new resistor and 22mm screws; the 7W resistor will already have an insulating Sterling sleeve on properly bent terminals.

Sounds great - thanks in advance.

Please check carefully the +5V analog supply, because it's a reference on DAC (I/O board) and therefore responsible for auto-tuning: the voltage between the regulator heatsink (output) and ground must read 5.05V.

Certainly - it was rock steady at 5.05 while playing the first chords after the time of illness.

The SPSU embedded +5V trimmer should be not touched, because it's related to the digital line.

Thank you very much for the feedback!

I always take some shots while doing major upgrades. Let me know if you want these along with some "rookie notes" and feedback.

Back to the Chroma - cheers,

Re: Registry Approaches 500 Instruments

Go to first message in thread, March 2008

Peter Forrest [21010096]

Hi Chris,

This isn't much help for the registry yet (I'm trying to find out the number) but there is a good condition Chroma on the VEMIA auction at the moment at www.spheremusic.com. Nice that it has all the bits. lot 5810:-

Fully working Arp/Rhodes Chroma in v.g.c with flightcase **and accessories**. This synth has been recently serviced by Cyberwave and has NO problems. Loaded with original factory presets; all voices tune correctly all buttons and switches function correctly. It is in very good condition for its age with no missing knobs. It is of course 25 years old so there is minor marking to the wood and some minor scuffs. It is not mint but anyone with reasonable expectations will not be disappointed. Very unusually it has all the accessories, original performance and programming manual, parameter chart, footswitch and pedals, etc. It comes with huge anvil flightcase in good condition apart from the usual peeling foam issues. SHIPPING WILL BE EXPENSIVE (£60-80ish in mainland UK) and because fo the nature of the Chroma we can't guarantee that shipping won't dislodge a card or somehow cause a problem, even though we will make the case safe and protect the Chroma from any peeling foam. So we would prefer for you to collect from Hay-on-Wye, or we will deliver for 60p/mile.

Riccardo Grotto [21010249+]

I bought a bunch of vintage synths from a studio closeout, last summer. All of them have already been sold as I also was re-sizing my collection. But I still have a dead Chroma: the batteries messed up the CPU board and affected also the board underneath the voice cards. Also, the foam of the case collapsed (de-polymer-isation).....an already known story. Too bad......it was a beatiful instrument which still belonged to the original owner. I will post the # number for the registry.

Peter Forrest [21010096]

The number of the Chroma in VEMIA is 21010227. I don't know anything about where it came from. I presume Cyberwave bought it as it was and serviced it.

Jesper Ödemark [21010135]

Wow, a direct sibling to our own mr PSU-Luca's Chroma (21010226) and no, the new one is not in the registry yet. :D

Luca Sasdelli [21010226]

Right, my Chroma S/N is 0226, and it was bought from Casale Bauer, musical instruments import brand for Italy.

Brian Marshall [21010108]

If the batteries have messed up the CPU board, have a look at the info on my Chroma - CC board acid damage repair info, March 2007.

I had the same problem - some of the smallest print track on the board was worn away by the battery acid - I repaired the track and the Chroma worked again. Good Luck!

Riccardo Grotto [21010249+]

Uh, I have 4 CPU boards from my old Chromas (they all have the new CC+) so I think that I will first install one of them......

Peter Forrest [21010096]

I went to collect this Chroma 21010227, and am taking it to the buyer in France in a few days' time. After what has happened to me in the past I'm paranoid about sending Chromas by courier if it can be avoided. It sounds superb and plays beautifully. Reminded me of what a fantastically rich sound a Chroma has.

Frank Hettlichs Chroma SPSU kit status

Frank Hettlich

Hi Luca,

do you have any status updates for my already paid Chroma SPSU kit?

Thanks a lot

Luca Sasdelli [21010226]

Hi Frank (and others),

I'm afraid in having that long delay, but the SPSU kit production is quite a long task, and I have to deal first with my paying job, my family and other high priority things :-)

Anyway, a second run is just to be tested, packed and shipped; I guess have all of them shipped before the end of this week.

register new entry

Riccardo Grotto [21010249+]

The s/n of the non working chroma I recently took at home is 21010225.

So it's the s/n just before the one owned by Luca [21010226]. The original and previous only owner, reported to have bought it from Casale Bauer, the italian importer at that time.

Fwd: Arp mid-1970s query

Chris Ryan [21030691]

Can anyone help Phil?

Begin forwarded message:

From: "Phil Hayward"
Date: April 8, 2008 4:34:33 PM PDT (CA)
To: Chris Ryan
Subject: Arp mid-1970s query

Hi Chris

I'm a music professor at Macquarie University in Sydney and have visited your excellent site. I wonder if you could help me with a query. One of my graduate students is writing a book chapter under my supervision on the soundtrack to 1975 film 'The Story of 'O''.

The music is by Matt Camison (who made a album called Pop-arp in 1973 under the name Mister K). I am trying to find out whether he also used an Arp on this film, or whether he also/alternatively used a Moog + any details about the soundtrack production.

It appears a cold, dead end so far. Any clues or suggestions for further contacts would be much appreciated

Best Wishes

Phil

Dr Phillip Hayward - Department of Contemporary Music Studies, Humanities, Macquarie University, Sydney NW 2109

Chroma SPSU kit - Second Batch

Luca Sasdelli [21010226]

Hi all,

I've just finished shipping the first batch (except for a couple of units, whose customer has already been informed).

There have been some more delays, due to component supplies, but now everything should be okay to start the second batch production.

This second production will see a revised PCB, with some error fixings and a slightly different layout, to allow the big 7W resistor have a more convenient layout and all power cables to be connected in a better way. The only substantial change is the addition of a small 12V power LED indicator, that should be on when both -12V and +12V are operating and near their nominal value; the +5V analog LED now is smaller and green, while the +5V digital will be indicated by the SPSU's internal LED.

In this way it will be possible to have the complete PSU voltage status at a glance.

The waiting list now counts 10 requests; I'll arrange for almost 15 units, so that some last-minute addition(s) would be serviced as well.

Speaking of replacement power supplies...

Greg Montalbano, Analog Synthesizer Service

I have a few replacement boards available -- designed to work with the Meanwell T60B supply.

Back when I was restoring my Chroma, I built the original Sandro board (How to Swap the Original Power Supply with a Readily Available Switching Unit), and since I had a few repair customers who were interested, I made several boards at once. Some of those customers have since dropped out, so the boards are available for $50 each plus postage. If anyone wants the T60B with it, add $70. These boards are tested & ready to go; they're the same as the schematic except for the manual reset button, which I left off (but if you need it, all it requires is the addition of a 1K resistor & a tact switch).

Mark Smith [2103-PT-002]

I'd like one of the boards! How do we do this?

Greg Montalbano, Analog Synthesizer Service

Paypal or check -- let me know which works for you.

(Rest of thread deleted as it was intended to be off-list)

Chroma on Craigslist Los Angeles

Chris Ryan [21030691]

"Fender Rhodes Chroma in very good condition...Is able to operate via MIDI." $1500.

Picture:

cc+ installed & two issues

Anders Elo [21010104]

I've now installed the great CC+ (thanks Sandro & Craig!) and I've surgically removed a kenton midi interface by cutting the wires to the IO-board. After powering up I noticed that the tapper suddenly started to work again (yay!) it has been all silent before...but it behaved somewhat strange. It started tapping randomly and sometimes in a very rapid succession depending on the selected patch/program and sometimes if I moved the parameter control slider. However it also tapped correctly when selecting a program. I suspected some grounding issue but found no obvious problem there. Since I didn't find the root cause and to get rid of the problem I simply removed the tapper, I didn't like it anyway. Has anyone experienced something like this or knows the most likely cause of this?

The next and much worse issue I'm having is that I can only get sound from the A-voice Boards, all eight works nicely but the B-voices are not sounding or at least not showing up when using the 'show voice allocations' feature. What could be the problem here or where should I start to troubleshoot?

Any help or ideas greatly appreciated.

Chris Ryan [21030691]

Check Technical Service Bulletin SN3-007: I/O Strobe Decoder.

Anders Elo [21010104]

Oh, perfect, I didn't locate that one yesterday. It seems to be exactly the problem that I'm experiencing with the tapper. One funny thing that struck me is that I have a 74LS138 littering on my desk. :)

The silent B-voice issue I suspect can be problems with one of the s/ h multiplexers as described in another technical bulletin.

I'm sure whatever problems I have the solution will be found here, it's time to make a donation! :)

David Clarke [21030085++]

...The next and much worse issue I'm having is that I can only get sound from the A-voice Boards, all eight works nicely but the B-voices are not sounding or at least not showing up when using the 'show voice allocations' feature. What could be the problem here or where should I start to troubleshoot?

Depending on what the display is showing, the Chroma may be behaving correctly (i.e., if the B voices are not being displayed in the 'show voice' output, then the Chroma may legitimately not be expecting to separately control those voices.)

Try different patch structures (e.g., 16-voice mode, etc.) and watch to see how the voice display changes.

Anders Elo [21010104]

Done that, I've also verified by muting the A channels with set split 26 resulting in no sound output. I'm going to shop a couple of 4451 and a 4556 and replace these chips on the i/o board.

Anders Elo [21010104]

That should have been 4051 8 bit multiplexer, not 4451 whatever that is, but now I don't think that is the problem since they are located on the voice boards. That could have explained a individual board failure but my problem concerns all the B-channels. Perhaps the problem is in the DAC section on the i/o board...I need to investigate this better. But I'll start by checking the i/o strobe as mentioned in an earlier post.

Anders Elo [21010104]

Problem solved, one of the legs to a transitor was chopped off when I cut a wire from the kenton interface. For your reference the transistor Q4 is located on the i/o board computer interface section.

Now both the tapper and the B-channels works fine again :)

Jesper Ödemark [21010135]

Congrat's Anders, we need more functional Chromas in Sweden! Which reminds me... again... :(

Anders Elo [21010104]

Thanks, I feel relieved! But what do you mean with your last sentence, is yours not working ?! :-o

Jesper Ödemark [21010135]

I have the Luca PSU in a box by the Chroma and I think the girl feel the need to get the upgrade 'cause sometimes I can play a few voices but they tend to get out of tune one after the other as I play ending up with a display saying "01234567" and autotune won't help. :(

So I really hope it's this. Before my long studio rebuild last year one voice (7?) would occasionally lose track, but otherwise it was a well-tuned chic. But I don't think forgave me that long absense and now it's as above...

Doesn't it sound like my original PSU is ready to give up? If not, what else can be the problem?

Anders Elo [21010104]

Sounds to me like you have nothing to lose, so get your hands dirty and swap the PSU.

I've reflected over my issues I had a bit and I'm sure the tapper problem was caused by Q4 being ehrm disabled. The voice stuff I'm not so sure about since I might have misinterpreted the function of set-split 37. And when I muted the A-channel I got no sound output which I though was a fault but perhaps that is normal on a layered patch.

Right now I'm so happy having my chroma fully functional again with a new brain.

I still have three minor issues left, output 3 is not working, probably caused by oxidation. And the sustain pedal is by default active after power up with the new PSU, a sw reset fixes this. I wonder if it is possible to just swap the polarity of the cables in the sustain pedal?

Finally the EQ is being noisy and distorting the sound a bit but I don't care about that since I use the individual outputs.

Åke Danielson [21010068]

Hey Anders,

I have the same problem with my Chroma and the new PSU. Pedal reversed at boot. A SET+SPLIT+50 will cure it but it shouldn't be like that. Anyone else an idea?

Luca Sasdelli [21010226]

SPSU timing issues

Hello all,

it seems that some timing problems are related to the reset circuitry within the SPSU PCB being inappropriate with some Chromas.

Currently, the affected instruments are:

I don't have this inconvenience on my Chroma: I've used a prototype and then tested some of new SPSU kits, but it works well anyway, so I can't track it for troubleshooting; because of a [SET SPLIT] [50] cures the fault, I can just suppose that the current reset is too short to allow proper reset at power-on.

Just as a first action, with the Chroma exhibiting the sustain pedal acting the wrong way round, press the Reset switch on new PSU PCB to see if the instrument goes okay. If so, proceed as follows.

If you feel quite confident with soldering iron, you can simply add a 10uF (or more) tantalum capacitor in parallel with the existing one on the one-shot delay timing, to elong the reset time at power-up. The new capacitor could be installed on solder side, under the current C201 capacitor (use this image for reference).

The tantalum capacitor is polarized, so please be careful in installing it: the plus (+) pole must go to the inner of PCB, while the negative will be connected to ground. Please do not use standard (electrolytic) ones, because of the different current leakage when full.

Awaiting your replies

Jesper Ödemark [21010135]

Re: SPSU timing issues

Luca Sasdelli skrev:

Hello all,

it seems that some timing problems are related to the reset circuitry within the SPSU PCB being inappropriate with some Chromas.

Currently, the affected instruments are:

Sounds like my Chroma (21010135) might belong there too if I'm unlucky. Funny how all swedish (imported) Chromas are so close in the registry...

I don't have this inconvenience on my Chroma: I've used a prototype and then tested some of new SPSU kits, but it works well anyway, so I can't track it for troubleshooting; because of a [SET SPLIT] [50] cures the fault, I can just suppose that the current reset is too short to allow proper reset at power-on.

Just as a first action, with the Chroma exhibiting the sustain pedal acting the wrong way round, press the Reset switch on new PSU PCB to see if the instrument goes okay. If so, proceed as follows.

I will...

If you feel quite confident with soldering iron, you can simply add a 10uF (or more) tantalum capacitor in parallel with the existing one on the one-shot delay timing, to elong the reset time at power-up. The new capacitor could be installed on solder side, under the current C201 capacitor.

The tantalum capacitor is polarized, so please be careful in installing it: the plus (+) pole must go to the inner of PCB, while the negative will be connected to ground. Please do not use standard (electrolytic) ones, because of the different current leakage when full.

I hope I won't have too... I rather stick to what I know. ;)

Chroma in synthesizer magazin

Jesper Ödemark [21010135]

Just stumbled across this today [from synthesizer-magazin.de]. It's not out yet I guess but maybe some of our german friends will give us a good review later?

Go to next message in thread, May 2008

The English and original German versions of the article were added to the site in September 2008.

SPSU question

Jesper Ödemark [21010135]

Hi list,

In the middle of changing the PSU in my Chroma I realised that the post haven't been to nice to my new SPSU so the effect resistor has broken off at the base. :(

I'm tracing a new and I've mailed Luca offlist, but trying to make something of this untimely break I studied the mail Luca sent the 20th of March which reads;

"The very first shipped kits exhibits some little bugs: - voltage regulator trimmer is loose, because of a PCB layout mistake: please keep the trimmer as upright as it should be"

I don't follow. Do I need to correct this error? I can see a bent leg but also a cut trace on the other side of the PCB. Does this mean I can ignore the info above?

"the two bracket fixing M3 Allen screws are too short (20mm instead of 22mm); the aluminum bracket allows to be installed even by forcing the original screws, but a pair of 22mm screws is much better."

Since these words about the screws being too short sure applies to mine I don't know what to make of the trimmer comment...

Luca Sasdelli [21010226]

Hello all,

the PCB trimmer path had an error, that required to mount it without reach the central pad, to avoid a short on +5V analog bus.

Therefore, the trimmer should have two legs (side and center) connected together and it shouldn't touch the underneath track(s). All first issued PCBs (horizontal regulation screw) have been modified this way, while the PCBs with vertical regulation screw have the track cut to overcome the problem.

New PCBs (they will be shown soon on Chris' website) have the track corrected and are currently under preliminary test.

About the broken resistor, this is caused by a (my) bad idea to install it in that way; the 47 ohm 7W resistor is used ONLY for the tapper voltage, so should the resistor be broken, the PSU will do always its task, except for the tapper, of course. All next PCBs (and new ones) have a different and safer layout, that should protect the resistor from breakage; some image will be published on Chris' website, as soon as he'll have some spare time for this ;-)

I'm sorry about that, therefore if any of you need some spare 7W resistor and the two 22mm fixing screws, please drop me a line and I'll send you. If you will have to replace the 7W resistor, please see attached image as an example of correct way; please note that the resistor wire looping underneath the component is insulated via a Sterling tube, to avoid contact with other resistors: a plastic sleeve, like the one coming from a common electric cable, is enough.

Scared of the CC+

Paul Hackett-Evans [21010094]

Hi,

I have a CC+ kit from the second batch, all still in the box and ready to install.

However, my Chroma is in perfect condition, and working as well as the day it was new. I have one of Ken Y's Chroma cult MIDI interfaces. I store all of my sounds on my PC using Emagic SoundDiver. I also use SoundDiver to control all the parameters on my Chroma, so the membrane switches get no wear and tear at all.

So SoundDiver is a very important part of how I use my Chroma.

My question is – has anyone tried using a CC+ Chroma with SoundDiver? Does it work as well as with the standard Chroma?

Sandro Sfregola [21010294]

Paul, the CC+ has been designed to be compatible with the Chroma Cult interface even at Control Change and System Exclusive messages level; so it must work with your preferred editor.

Just try it: if you have problems please let me know.

Paul Hackett-Evans [21010094]

Thank you, Sandro.

I've been scared to install it in case I lost the functionality of using SoundDiver.

Now I know it should be okay, I'll give it a try when I have a day I can work on it without the children constantly interrupting...!!!

Jimmy Moyer [21030184]

A very cool thing with the CC+ is that its new, built-in MIDI interface works simultaneously with a Chroma Cult interface.

I run my editor with its monitor on top of my Chroma on a separate PC from my sequencer across the room. I used to have to use a MIDI patch bay to change routing between sequencing and editing. Now I can connect and use both at once.

Enrico Dibennardo [21030494]

(not) Scared of the CC+

Not clear if a CC+ board can be ordered at any time or if there are typical "run periods" once or more times a year.

Help needed: where can I get Chroma Faders

Daniel Rickenbach [21010172]

Hi

I have a Chroma to repair an d I have the following problem: The battery acid from the memory-buffer-battery has damaged all the Chroma faders on the front panel. The Chroma was 15 years not in use and it looks that Chroma was stored in this time with the left keyboard side at bottom and the right at the top. So the battery acid has trickled down via I/O-board to all the faders (1 on the I/O-board and in a next step to the 5 faders on EQ-Board).

Now I'm looking for a replacement for these faders. Knows someone, where I can get Chroma-Faders oder similar types, which I can use as replacements for the original faders?

Thank you very much
Daniel

(Chroma SN 21010172, it is not on registry yet, but I will do it asap.)

Jesper Ödemark [21010135]

I only feel the need to say; "You lucky bastard!" that it was stored that way. Better with a bunch of dead potentiometers than wrecked voice card which is normally the case.

Good luck with the service and welcome!

John Leimseider [21030434++]

Cantos bought the Chroma parts that were at MusicTek... When I was at MusicTek, we bought what Fender had left when they decided to get out of the synth business. We have faders, some knobs, plus lots of other parts. Shipping from Canada can be a little expensive, but we probably have what a lot of Chroma owners need.

My Chroma and Expander are listed, as are the set in the Cantos collection. If people let me know what they need, and are a little patient, I'll try to help.

SPSU Install It's Alive!

Paul Tillotson [21030218]

I just got my new SPSU kit and installed it today and, wonder of wonders, it powered right up for the first time in years. It did fail autotuning on all voices, but that's no doubt a wrong voltage to the I/O board which were wrong before I installed the new power supply. I've mostly fixed that with what I'm afraid can be best described as random adjustments to the trimpot on the I/O board. It now passes all boards but number 3, which has been acting up for years. I checked the voltages from the analog trimmer and they are set at 5.5 as instructed, if I took the measurements correctly.

Problem is, autotuning or resetting the instrument still results in a badly out of tune instrument: octave scaling off; different boards with different degrees of detuning between oscillators. I think I need to check the voltages to the I/O board which I know were off before it died. Can anyone help walk me through that procedure? Please tell me that I didn't wreak anything with my stupid random behavior.

I am most thankful to Mr Sasdelli for his work on the SPSU kit, it wasn't too hard to install and he's been good at keeping folks informed. Now if I can tune the darn thing and find the MIDI interface in my studio, I'll be in heaven!

Luca Sasdelli [21010226]

Hi Paul,

first of all, thanks a lot for the feedback :-)

Please note that +5V analog should be 5.05V and not 5.5V ...

AFAIK, the I/O board requires trimmer adjustment to read zero between the two test points close to it. The voice board procedure consists in adjusting voice trimmers to obtain 50% duty cycle on each VCO: this can be obtained either via a scope or by ear; I prefer the second one. Simply connect a headphone with jack tip to the voice board test point and shield to ground, and adjust the trimmer to reach the typical "hollow" sound of the square wave (zero even harmonics). I suggest to have a first adjustment with only a voice board installed at a time.

Remember: during tune procedure, the object is the waveshape and not its pitch :)

Before any adjustment, issue a [SET SPLIT][31] to be sure no initial bias is applied to the VCOs and bad tunes are ignored.

Anyway, your reference is Hardware Fault Diagnosis & Repair

Paul Tillotson [21030218]

Okay, with some informed voltage adjustments to both the analog line and the I/O board I'm now in tune and have all voice cards working except the usual suspect voice card #3.

I've loaded in the Walt Whitney banks and am tweaking those. They need some performance controls and modulation routings added but once you do that you're in totally fantastic synth heaven. Man, I've missed this instrument. The power supply is rock solid, stable, quiet and generates no heat.

The one issue I see is that I have to be added to the list of folks who need to reset to get the sustain pedal to respond correctly. I can live with that.

Luca Sasdelli [21010226]

Hi Paul,

can you please check if the sustain pedal issue is cured with a reset on SPSU PCB?

Jesper Ödemark [21010135]

The one issue I see is that I have to be added to the list of folks who need to reset to get the sustain pedal to respond correctly. I can live with that.

Right - I haven't tested that. How was it again, is sustain never released or what? (bad memory) Please let me know and repeat the cure too and I'll test mine too.

But it's somewhat "good" to see it happening to 2103's too...

Luca Sasdelli [21010226]

Hi Jesper,

the fault is shown as a reverse action of sustain pedal (sustain when released and stop when pressed), and is known to be cured by issuing a [SET SPLIT][50] soft reset.

My Chroma doesn't suffer of this issue, so I can't simulate it; therefore I'd like a response from whom affected to this, if clicking the Reset button on SPSU PCB, with Chroma in this "reversed sustain" condition, does cure the fault as well.

If so, there is the need to increase the reset timing, by changing the value of C201.

Jesper Ödemark [21010135]

Splendid - I'll check next time I'm in the studio (keeping the mail now).

Paul Tillotson [21030218]

On my Chroma, using the reset button on the SPSU board does fix the reversed sustain issue.

Luca Sasdelli [21010226]

Thanks Paul,

definitely the C201 10uF tantalum capacitor needs to be increased to prolonge the power-up reset; I can mail an additional capacitor to some users for testing: it will have to be soldered in parallel with the existing one, near the reset button.

Jesper Ödemark [21010135]

Luca Sasdelli skrev:

Thanks Paul,

definitely the C201 10uF tantalum capacitor needs to be increased to prolonge the power-up reset; I can mail an additional capacitor to some users for testing: it will have to be soldered in parallel with the existing one, near the reset button.

Unless my letter isn't already on the way you can send it along. I will have to dig into mine again anyway...

Luca Sasdelli [21010226]

Hi Jesper,

I still have to send it, so I've put in a tantalum cap as stated; you can solder it underneath the PCB, just in parallel with the existing C201 close to the Reset button. Pay attention to capacitor polarity.

Jesper Ödemark [21010135]

Splendid, I'll do that then. Just to be 100% sure: +2+ and -2- right? (now I sound really foolish, but better to ask) :D

Jesper Ödemark [21010135]

...sorry, I could've sent that offlist! :S

Luca Sasdelli [21010226]

Splendid, I'll do that then. Just to be 100% sure: +2+ and -2- right? (now I sound really foolish, but better to ask) :D

Yes, correct; the plus (+) terminal must be towards the board inner. I'll implement this even on the new kits to be shipped.

Sorry for the list, but because I wasn't aware that I responded to the list, I prefer to complete the info in benefit to others.

Jesper Ödemark [21010135]

Cool!

I don't mind being regarded a slow-thinking electronics rookie as long as my Chroma work. *laughter*

Send and receive Chroma programs

Mark Smith [2103-PT-002]

HI -

I just got my Chroma 2103-PT02 running and I'm thrilled. Thanks to the list for the information I got from it. Now, I'm figuring out how to send and receive programs in sys ex from my computer through the Syntech MIDI into the Chroma. The Syntech manual isn't enough information. Can anyone help? I'm using MIDI-OX.

Mark Smith [2103-PT-002]

List -

I am able to send and load programs now - you just send them!

Thanks anyhow, Mark

CC+ support and more

Sandro Sfregola [21010294]

I apologise to all users for the lack of support from me in the past days but I've been forced in bed for more than a week, being struck from a (luckily) slight form of labyrinthitis; this kind of disease cause strong dizziness and nausea at even the slightest head movement.

Luckily I'm recovering well and I can work and drive again now; also the work on the CC+ has resumed.

Checking before install SPSU kit

Sandro Traversi [21010217]

Hi all. Just arrived my SPSU kit (very nice), but it's a long time (some months) I do not switch on my Chroma. So before installing the kit (really pro) , I decide to try to start the beast, just to check everything is ok ... Immediatly at the start, it do not complete autotuning , all leds are blinking but not as "brilliant light" and tapper gives knocks in syncro with leds. So I switch off soon, then on again. Same story. Many times. Or worse, a couple of fuses blown. I try again with Chroma opened and a tester pointed at Channel mother board, just to measure +5v . On switching it gives no more +2,5v. I'm not a technician, but my impression is it can get enough power so can't reach the +5v and complete autotune and works and so on .... What to do? Throw the old PSU in the trash and mount the new kit ? Or maybe I'd check more before install the SPSU ? Any hint ?

Jesper Ödemark [21010135]

Sound like it's heading the same way as mine was which stood silent for almost six months before asked to get back to duty. It refused to tune and started humming and behaving weird. Also blinking etc was random from time to time.

If I were you I'd install the new PSU, adjust and say a little prayer and I think it'll help. Keep us posted and do await more opinions... :D

Riccardo Grotto [21010249+]

This is briefly in english, then in italian.......more correct Make a power plug with the wires which have to go to the power socket of the chroma. Let the new SPSU lie on top of the instrument BUT you have first to isolate the whole thing. Then you can connect the ........connectors (P 1,2,3,4) to the SPSU board. Insert the plug into the A.C. main supply.......it should work. If it does, you can take the old PSU out and install the new one.

Oilalà, allora, prendi i fili che dovrebbero andare alla presa di corrente del Chroma. Con questi, fai una spina (da presa di casa). A questo punto LO SPSU può essere connesso direttamente alla presa di corrente. Se lo posi in cima allo strumento, isolandolo da qualsiasi altra cosa (specialmente le schede dello strumento aperto) dovresti avere cavo abbastanza per poter collegare i connettori alla basetta dello SPSU. Controlla tutti i collegamenti e a questo punto, inserendo la spina nella presa di corrente, il Chroma dovrebbe accendersi. Io, per provare lo SPSU senza prima levare il PSU originale, ho fatto così. Verificato il funzionamento del tutto, ho smopntato il vecchio PSU e sostituito con quello nuovo. ciao r

P.S. non è che sta cosa mi è venuta in mente subito........ho prima fatto fuori l'expander........ma con il Chroma ha funzionato.

Paul Tillotson [21030218]

Yank out that powersupply and install the new SPSU. Why do you torment yourself? My Chroma didn't work for years because the old PSU could not provide the needed voltage to the motherboard and I/O board. Go for it and you will not be sorry.