[sdiy] Rare chips on ebay

[Tom Wiltshire]

Eminently do-able, I'd have thought.
The SSM2040 might be famous, but it isn't complicated. There's  
4xTransconductance amps and 4x Op-amp buffers on the chip, and that's  
about it. No resonance VCA even.

If I were to try a SMD copy, I'd probably start with Analog Devices  
SSM2164 quad VCA for the transconductance amps, and some basic op-amp  
for the buffers. I suppose the real trick is getting it to sound  
right. Still, Prophets will be making noises for some years yet, even  
after all the 2040's die.

T.



On 24 May 2008, at 03:47, James R. Coplin wrote:

> Yes, I suspect they will be that expensive.  However, I am holding  
> out hope
> that with miniaturization, you should be able to make compatible  
> discrete
> replacements for the chips in smt format.  Should be possible,  
> shouldn't it?
> Most of the synths have extra space in the carcass so there should  
> be room
> for a really small board that would fit over the chip socket.  At  
> least,
> that's what I'm hoping.
>
> James R. Coplin
> (郭杰明)
>
> ***************************************
> Work is the Curse of the Drinking Class
> ***************************************
>
>
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
>> bounces at dropmix.xs4all.nl] On Behalf Of Barry Klein
>> Sent: Friday, May 23, 2008 7:28 PM
>> To: synth DIY
>> Subject: RE: [sdiy] Rare chips on ebay
>>
>> So in 5-10 years, will Prophet 5's and Memorymoogs be 10K$ - or less
>> than
>> they are now?  At 50 bucks a pop to replace chips now it gets kinda
>> scary
>> holding on to them when the chips seem just to die from old age (and
>> they
>> ARE old).
>>
>> Barry
>>
>>
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom  
>> Wiltshire
>> Sent: Friday, May 23, 2008 4:52 PM
>> To: synth DIY
>> Subject: [sdiy] Rare chips on ebay
>>
>> You don't see THESE every day:
>>
>> http://cgi.ebay.co.uk/10pc-NEW-SSM2040-VCF-sequential-circuits-
>> prophet-5-
>> LTD_W0QQitemZ290230749972QQihZ019QQcategoryZ29552QQssPageNameZWDVWQQr 
>> dZ
>> 1
>> QQcmdZViewItem
>>
>> They're not cheap, but then, they wouldn't be, would they?!
>>
>> T.
>>
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