Polymoog Reliability (once and for all!!!) Feb 22, 2011 22:45:17 GMT
Post by brassteacher on Feb 22, 2011 22:45:17 GMT
I had a very kind donation of the insides of the polycom IC and am in the position to make, er well one to start with. Of course I have the original PM to try it in so should be a synch! (Optimism is very useful).
I understand what has been said with regards making things to keep them going in as near to the original as possible - like making a polycom card - and maybe there is mileage in that as it's a simple job to replace one; compared to taking everything out and starting from scratch. The thing that bugs me the most is all those connectors.. mechanical things are usually the first to fail.
Once the polycom is out of the way as a hurdle the rest should be easy enough. Everything is more or less still available or at least there is something available that will do the job in the same way.
As to mounting surface mount parts we have an automatic pick and place machine so that's not a problem.
I rather like the idea of putting a re-vamped one next to an original to see if anyone can tell the difference without knowing which is which! (Might be a good excuse for a world challenge)
That's cool! I'd love to know what's inside, at least as far as circuits go, i.e., how many waveshapers, filters, VCAs, EGs, etc.. It would be interesting to see how these were implemented also. ICs are usually 10 times more complex, or 10 times more simple on the inside than a lot of people realize. For instance, it is possible to make a hex buffer chip with as few as 6 transistors total, and a quad 2-input AND gate chip with as few as 8 transistors total.
Another thing I'd love to know is how did the Moog factory go about calibrating a Polycom card.
I've also learned recently that the LM13600 is still being made as an SMT chip (NJM13600), and they are CHEAP. That's as good (and identical except for pinout) as having two CA3080s on a chip, and two buffers to boot! Just two of those chips, with an SMT 556 chip, and you could build a complete monosynth in a space the size of a Polycom card, incuding an LFO even, for less than $6 in parts.