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ChromaTalk Archives: February 2004

Polaris as Chroma-to-MIDI?

Doug Terrebonne [21030114]

So now that i have a working Chroma (and Polaris), I was wondering if I connected the Chroma to the Polaris could I use the Polaris as a Chroma-to-MIDI converter? Can the Polaris recieve notes over the Chroma interface and output them to its MIDI out? The Polaris manual doesn't seem to say anything on the subject...

David Clarke [21030085++]

Doug,

I'm sure it would not have been a difficult addition to the Polaris' firmware - but alas, as currently implemented the Polaris won't do any protocol to protocol conversion.

This means that you can go Polaris -> Chroma over the interface and Chroma -> Polaris, and Midi -> Polaris and Polaris -> Midi ... but no Chroma thru Polaris -> Midi.

I fiddled with this a bit back in 1994/95. There'a brief blurb in the Analog Heaven archives. Take a peek at: http://www.retrosynth.com/ah/search/search.cgi and search for "chromaface". The second note - from March 1995 - talks a bit about this.

David Clarke [21030085++]

http://www.retrosynth.com/ah/search/search.cgi ...

For any/all looking to use this link, you'll likely have much better success with:

http://www.retrosynth.com/ah/

hi everybody i am still looking for vocal and choir sounds for the chroma

Olli [21010284]

can anybody help me out with such sounds? i havn't found any so far and they are quite difficult to program.

ChromaTalk keeps me ChromaThinking... Z4 quest continues

Mark A. Lange [21030459+]

The thing I like about ChromaTalk is that it keeps me ChromaThinking and ChromaBelieving that I'll be able to resurrect one of mine! Congrats Chris on being such a great catalyst - I still remember the first time I saw the site and the factory patches in .WAV format - unbelievable!

My current quest ...

I got derailed trying to "fix" my Chroma last July/August. Anyway, as the weather has been crummy recently in beautiful Washington State, I figured "I'm gonna install those NTE4906 overvoltage regulators and see if some of Murray's tips might bring a solution".

Well, smoke rose again.

Not from Murray's tips, but from the replacement-replacement NTE4906 / power supply Z4 substitution. After removing the dead component, I fired-up the Chroma to check on the current state-of-affairs.

IT WORKS!!!!!! And seems to be working great - all resets, tunings, audio quality, keyboard and front panel functions are perfect.

However, being that the power supply's Z4 is an "Overvoltage Regulator" I'm not convinced that I'm out-of-the-woods, yet. C3 in the power supply measures at 16.98 - 17.5 volts DC on the + side of the capacitor.

Many thoughts - one being that this cannot be a safe situation. Also, am I correct in connecting the cathode band/side of Z4/NTE4906 to the + terminal on C3? Finally, if this C3 voltage seems "OK", how about another Z4 substitution? Any good idiot-proof Chroma replacement power supplies???

Sorry to bore you with the gory details, but I really appreciate everyone's help!

Oh well......

Mark A. Lange [21030459+]

Wise Ones!

In case this helps troubleshooting, after sitting off for an hour the Chroma no longer powers up. No front panel activity at all - just a "bump" sound through the speakers when switched on. C3 + side voltage reads 14.4 volts DC and ramps towards 20V over the course of a minute or so. I got nervous and turned it on-and-off a few more times, to no avail.

It mocks me, as it sounded so good at lunch time.

Enrico (Italy)

Enrico Dibennardo [21030494]

hello, I'm new to the list and I find this Chroma site and its list really a fantastic tool and a true opportunity for Chroma owners since I've been lurking for a while.

Here are a couple of questions I'd like to pose to the list

  1. (very simple) My Chroma was purchased in USA (I got it here in Italy but the one who sold it to me had got it from USA) it has always been used with a step down transformer and it works fine, opening the unit I found a Voltage selector inside so 220 can also be selected but I want to be sure of a couple of things before trying. I have the service manual and the selector is mentioned but I couldn't find any detail related... I mean is there something I should change? (junkers, connections...) is there a fuse somewhere should be replaced? I'll wait for a reply on this list before trying of course.
  2. Only six voices out of eight are working. If I skip the diagnostic routine 7 boards are working but what is strange is that the one that was automatically disabled seems to work fine while there's another one that is always enabled by the routine but if I skip the routine I find that it is about one octave below it's normal pitch. Autotune works fine with this board and it gets enabled and tuned everytime, I consider this as an odd behaviour while I don't understand why the one that seems to work fine is always disabled by the routine. I'm quite sure of what I'm describing since I did lots of attempts shifting or removing the boards from their locations. One board instead seems to be dead and I'm not asking to the list to tell me which component(s) failed but of course I'll be glad to receive any indication for how to start for a correct inspection.
  3. The velocity response sounds rather uneven and I can notice that it feels like all boards react differently to how the filter "opens" but if I play individually each note I can't say there's something wrong: If I press hard it opens, if I play very soft it is mellow and closed and all other intermediate "nuances" are there at different depressing velocity but still I can not get a scale I.E. with an uniform color. I just ordered a cult midi kit from Ken and I'm curious to see if the behaviour will be the same playing just the generator from an external keyboard. I mean, of course, that I have no idea if the problem is a setting of each board or a problem related to the keyboard or to the keyboard controller. I think people of this list may have encountered a similar problem or at least I hope.

Sorry for the long message and many thanks for fothcoming replies.

Olli [21010284]

hi enrico

hello, I'm new to the list and I find this Chroma site and its list really a fantastic tool and a true opportunity for Chroma owners since I've been lurking for a while.

i agree 150%

1)(very simple) My Chroma was purchased in USA (I got it here in Italy but the one who sold it to me had got it from USA) it has always been used with a step down transformer and it works fine, opening the unit I found a Voltage selector inside so 220 can also be selected but I want to be sure of a couple of things before trying. I have the service manual and the selector is mentioned but I couldn't find any detail related... I mean is there something I should change? (junkers, connections...) is there a fuse somewhere should be replaced? I'll wait for a reply on this list before trying of course.

generally, you do not have to change anything. just switch the switch.

2) Only six voices out of eight are working. If I skip the diagnostic routine 7 boards are working but what is strange is that the one that was automatically disabled seems to work fine while there's another one that is always enabled by the routine but if I skip the routine I find that it is about one octave below it's normal pitch. Autotune works fine with this board and it gets enabled and tuned everytime, I consider this as an odd behaviour while I don't understand why the one that seems to work fine is always disabled by the routine. I'm quite sure of what I'm describing since I did lots of attempts shifting or removing the boards from their locations. One board instead seems to be dead and I'm not asking to the list to tell me which component(s) failed but of course I'll be glad to receive any indication for how to start for a correct inspection.

did you check if its not a slot on the channel motherboard which has a problem? that happened to me, i thought a DCB was KO but it was a CMB problem. check the molex connectors on the boards sometimes those need changing when the contacts inside break. i had this prob on one DCB. this is an easy fix. i discovered it after having changed 6 chips on the board.

3)The velocity response sounds rather uneven and I can notice that it feels like all boards react differently to how the filter "opens" but if I play individually each note I can't say there's something wrong: If I press hard it opens, if I play very soft it is mellow and closed and all other intermediate "nuances" are there at different depressing velocity but still I can not get a scale I.E. with an uniform color.

check setting up another velocity response (parameter 13)

I just ordered a cult midi kit from Ken and I'm curious to see if the behaviour will be the same playing just the generator from an external keyboard. I mean, of course, that I have no idea if the problem is a setting of each board or a problem related to the keyboard or to the keyboard controller. I think people of this list may have encountered a similar problem or at least I hope. Sorry for the long message and many thanks for fothcoming replies. Enrico (Italy)

good luck and keep me posted

olli

Olli [21010284]

btw, are you in rome?
olli

Enrico Dibennardo [21030494]

Many thanks for the reply, so you think I may dare switching the switch? (i'm talking of the 110-220 voltage selector)

did you check if its not a slot on the channel motherboard which has a problem?

I don't know if I got exactly what you mean, in any case all 8 boards did mantain their behaviour disregarding the slots they were inserted in, I put all the boards in every slot just to be sure that the problem is the card itself and not something else, I think this is correct.

check setting up another velocity response (parameter 13)

I will try I had missed this parameter, BTW is there a possibility to totally disable key velocity? I couldn't absolutely disable it though I did many attempts.

No I'm not located in Rome I'm in Catania (Sicily) and we had a pleasant springtime weather today :-)

Olli [21010284]

you might have to change the fuse but i the worst case it might blow. i don't see what else could happen. generally, you have to change the fuse for a lower value.

I don't know if I got exactly what you mean, in any case all 8 boards did mantain their behaviour disregarding the slots they were inserted in, I put all the boards in every slot just to be sure that the problem is the card itself and not something else, I think this is correct.

ah OK. well than it is a board problem. check the connectors first and then try to identify which channel doesnt work disabeling first A, then B etc. you can find the isntructions in the service manual on the site. it is a PDF file. look for the SETSPLIT commands.

I will try I had missed this parameter, BTW is there a possibility to totally disable key velocity? I couldn't absolutely disable it though I did many attempts.

well set 13 and 20 to 0

No I'm not located in Rome I'm in Catania (Sicily) and we had a pleasant springtime weather today :-)

i think i just cought a cold jogging in the park. 3íC... oh yeah sicily.... i remember from a trip when i was 13 years old.

Five Years

Chris Ryan [21030691]

The Chroma site first went live five years ago today — it was five pages I pulled together over the course of an afternoon and evening. Back in 1999 I certainly didn't expect the audience, longevity, and growth that it's enjoyed; or to have heard from so many owners from all over the world and interviewed some of the people who designed and built the instrument at ARP! A sincere thanks to all who have contributed content and participated in the mailing list. Despite a recent lack of updates, the number of weekly page views continues to edge up.

The HTML has been showing its age, and In recent months I've been working on a major revision to the site which will make updates and maintenance much easier. I've had a few other things on the go; and I've twice gone "back to the drawing board" with the project (once to fully separate content from markup using PHP, and again to move to strict XHTML with pure CSS layout). I hope to have the new site ready in the next few weeks, and will then resume regular updates: I have lots of new stuff to post.

Thanks again to all, and I look forward to another five years of discussion and activity.

See Ten Years, February 2009.

Richard Ardery [21030562]

Thanks Chris...it is a great site!

Rich Hilleman [21030351+]

Chris, you are very simply the reason I have a Chroma, and now I have three.....

Jeff Bova [21030407++]

Thanks Chris and congratulations on such a great site and resource!

Olli [21010284]

hi chris,

THANK YOU again and congrats for this great site. had it not been in existence, i would not have purchased my chroma. the help of list members was essencial to repair my synth as well. this i a great job and i hope it will continue! i wish you all the best and if i can be of some help..

Luca Pilla [21010218]

Thank you Chris! You and your site are my swiss knife for my Chroma

Sandro Traversi [21010217]

Congratulations Chris and many Thanks. Due to your site I buyed and restored and I'm still reparing my loved Chroma. I really think Chroma site is the best web site about an analog synth.

Jeffrey D. McEachin [21030073+]

I wish every synth I owned was so well supported. Thank you for your efforts!