> Sorry that I have not followed this thread closely. The photos
> are nice! I see a LOT of work went into that.

Thanks. I'm pleased to have the PSU sorted out and at last managed
to have a play around with 4-voice stereo. The original was based on
a uA723, op amp followers and bypass transistors. I remember some
parts getting quite hot. It had suffered moisture damage in storage and
was probably kaput judging by the verdigris in all the wrong places.

As the 4600 uses CMOS logic rather than TTL the original PSU had
a very small (50mA) 5V output and no 12V, so I'd have had to make
a second PSU for PICs etc. anyway. I've retained all of the original
logic+analogue circuitry because it has "character" and augmented
that with micros+DACs for eg complex control voltages, trigger
dividers/multipliers/delayers/routers, echoes, etc and timer functions
which would be extremely difficult to do with analogue circuitry. For
example fitting an ADSR envelope or filter cycle exactly between two
triggers or a % of the time

The original sequencers were fairly simple, basically pots, 4520 and
4051s. PICs have gone into those too, adding to the power budget

As you say, a lot of work. The Flickr album could easily be several
times the size

> At night, it was switched to the center tap to get 250 W output

Better propagation at night ?


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