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IC's long gone..

Posted: Fri Dec 17, 2010 3:54 am
by sqweebking
So ive been wondering what will we do when the stock of all the rare and discontinued IC's from our coveted analog synths dries up. I was thinking last night about my Mono/Poly, im pretty sure its got a failing voice, which would most likely require replacing one of the SSM 2033 IC's that have been long discontinued. I know they can still be found every now and then, but what happens when they cant be? Is there any way to prolong the life of the remaining chips or prevent them from going wrong in the first place? For instance the Juno 106, it seems that most failed vcf chips can be mended by removing the coating from them. So thats a somewhat easy fix if the chip hasnt completely failed, but what about other IC's. Is there any rhyme or reason for them failing? Maybe a cheaper part up or downstream from it caused the failure?

Im obviously no electronic engineer, but id be curious what one had to say about this matter. I know these synths are getting old, and a lot of them need caps, op amps, etc. replaced or are these IC's just prone to fail after an undetermined length of time too? I was also curious what it might take to get a run of chips made? Datasheets for old discontinued chips are readily available but could they be duplicated somehow?

Re: IC's long gone..

Posted: Fri Dec 17, 2010 4:06 am
by 8bit9bot
i worry about this stuff too ._.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 4:43 am
by rhino
Last I heard, a run of custom ICs (including design of the dies) was about $100,000. Maybe some of the China places are hungry enough to go lower. A cheaper dirty solution would be to design small boards with the ICs in question duplicated by a group of modern chips. Maybe a flex cable to go to the original socket or pads.
The miniscule number of vintage synth nuts (compaired to the total of all nuts on the Earth) will no doubt scare anyone from attempting a large-scale repro pf the various chips. Been my dream for some years, but I'll have to leave that for you younger gents.
In the meantime, as chips get more and more scarce, the prices will go thru the roof... those who can afford them will have them...those who can't will go begging.

EDIT: Maybe in the future someone will design a single chip that can be programed to emulate many vintage chips.
Maybe in a surface-mount package that could be mounted on the correct-pinned header.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 4:58 am
by sqweebking
To me, 100 people willing to pay $100 each for a chip that has failed and crippled a beloved synth doesnt sound too far fetched. Maybe im crazy, but one day it could come down to that..

As far as building replica's on small pcb's that could be pinned out to match the existing sockets or pads, would that run the risk of any copyright or patent infringement? If I had the knowledge id be more than willing to put in the time to help with such a project but for now it may have to remain a dream.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 5:44 am
by adhmzaiusz
sqweebking wrote: As far as building replica's on small pcb's that could be pinned out to match the existing sockets or pads, would that run the risk of any copyright or patent infringement?
Hmmm this is a good question, because I know that actual circuits can be copyright but if you take a schematic and draw the circuit in a different way i'm pretty sure its not copyright. But within an IC theres no way of really seeing the circuit inside, when it could be a totally different circuit and same pin out.

Funny thing is, with the roland chips specifically ie the ba662, it is just a quad op amp which could probably be made pretty easy I assume. Be nice if some millionaire musician decided to reproduce these chips for the good of the earth.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 6:41 am
by Hybrid88
Yes, this does concern me too. Though I'd rather have the task of looking for CEM chips than the custom one's in the CS-80, or SSM's for that matter.
sqweebking wrote:To me, 100 people willing to pay $100 each for a chip that has failed and crippled a beloved synth doesnt sound too far fetched. Maybe im crazy, but one day it could come down to that..
Except 100 x 100 is 10,000, not the 100k Rhino said it'd cost :)

Re: IC's long gone..

Posted: Fri Dec 17, 2010 11:07 am
by nathanscribe
adhmzaiusz wrote:Funny thing is, with the roland chips specifically ie the ba662, it is just a quad op amp which could probably be made pretty easy I assume. Be nice if some millionaire musician decided to reproduce these chips for the good of the earth.
No it's not, it's a single OTA, like the CA3080, which is also out of production. But your general point stands, that there are several chips labelled by manufacturers with their own codes that can be substituted with generic equivalents.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 12:35 pm
by sqweebking
Except 100 x 100 is 10,000, not the 100k Rhino said it'd cost :)
Lol drunk math fail..

Re: IC's long gone..

Posted: Fri Dec 17, 2010 1:26 pm
by Altitude
PPl just need to start cloning the circuits with modern components. Already been done for the Juno chips and the BA662

Re: IC's long gone..

Posted: Fri Dec 17, 2010 3:06 pm
by th0mas
As an avid DIYer with few vintage boards the looming crisis I most worry about is the trend for manufacturers to stop making their chips available in DIP and instead only SMD footprints. I'm getting older, not younger.. I don't see my accurracy improving to that degree :/

Re: IC's long gone..

Posted: Fri Dec 17, 2010 5:44 pm
by adhmzaiusz
nathanscribe wrote:
adhmzaiusz wrote:Funny thing is, with the roland chips specifically ie the ba662, it is just a quad op amp which could probably be made pretty easy I assume. Be nice if some millionaire musician decided to reproduce these chips for the good of the earth.
No it's not, it's a single OTA, like the CA3080, which is also out of production. But your general point stands, that there are several chips labelled by manufacturers with their own codes that can be substituted with generic equivalents.
Oh yea you are right, I was thinking of the IR3109 which is a quad something or other

Re: IC's long gone..

Posted: Fri Dec 17, 2010 6:00 pm
by cornutt
adhmzaiusz wrote:
Oh yea you are right, I was thinking of the IR3109 which is a quad something or other
It's a quad OTA.

Re: IC's long gone..

Posted: Fri Dec 17, 2010 7:03 pm
by nathanscribe
I should add the 662 is also buffered internally, whereas the 3080 isn't, so it's not a direct replacement (pinout regardless).

I've seen some things cloned using PICs, but I have no idea how well they work:

http://www.electricdruid.net/index.php?page=projects

Re: IC's long gone..

Posted: Fri Dec 17, 2010 11:03 pm
by Computer Controlled
The BA6110 is a direct replacement for the 662.

Re: IC's long gone..

Posted: Sat Dec 18, 2010 5:44 am
by sqweebking
Sure there are modern equivelents to be used, and thankfully still analog synths being made. Are there any ways to prolong the existing IC's though? Or do we have to deal with the fact that one day these synths may die forever? :cry: