Hi all...Help on 921 tempco
Posted: Thu Jan 13, 2022 5:34 pm
Hi,
which type of tempco is used for the 921 VCO, and how is it mounted?
which type of tempco is used for the 921 VCO, and how is it mounted?
the tempco used for the 921 are 1k±3% TC. In the original Moog construction they used Tel Labs Q81, which nowadays are quite hard to find. I purchased mines from Synth Cube some years ago; don't remember the exact part number.
According to the original Moog 921 construction, the TC is mounted under IC508 (3046), that is mounted on sil sockets, so that enough room is available for the TC. Here are some close-ups taken from my 921 clone.
This is the same, with the IC removed, showing how the TC is mounted.
The TC should be in touch with the bottom side of the IC, with some heat sink compound, to improve thermal coupling
Hope this helps
All the best
Leonardo