This weeks delight/angst has been a very flaky 1979 8-voice OB-X in from the studio but shelved because was resetting/crashing all over the place with intermittent CV channels, dodgy front panel pots and no sync on one voice card.
What with the cost of components these days the notion of "shotgun" component replacement during a major overhaul makes a lot of sense in some instances....
To give you some idea you can buy a hundred CD4051 multiplexor chips from Farnell for less than $20 and $4 will buy you over 50 electrolytic capacitors!
By far the most expensive parts were a full set of replacement keybed bushings but rebuilding the keybed has made a massive difference and well worth the effort.
So I decided to change all of the PSU caps, regulators, (uprated) rectifiers, tantalum capacitors, CMOS multiplexors, tri-state buffers, op amps in the CV and sample/hold circuits (although I deliberately retained all of them in the audio paths bar the final mixers as they were populated with different parts on each channel). Even the original Mostek branded Z80 processor with hellishly tarnished pins was replaced (they are still available to this day).
Almost all of which were the 35 year old originals...
Why so drastic you might ask... because this is very much a workhorse in the studio and its flaky nature had rendered it pretty much a doorstop.
She's a delight to play again - just waiting for the Encore MIDI kit.
