The story began with the need for a Dynaco ST-70 to develop new and unique driver boards for them. A few emails to friends located a ST-70 in the basement of Planet10-HiFi and I was free to use it for R&D purposes on the condition that I get the unit working.
I was able to pick up the Dynaco on a spring visit to Planet10.
NOTE: NEVER run a ST-70 or clone without a protective cover! Accidents happen and your wife or child (especially the furry kind) may pay the ultimate price for it!
The ST-70 As Received
I snapped a few pics as she landed on my bench. Top:
Front:
Rear:
Top rear:
Top front:
After an inital check on capacitors and a terrible "cancer" that had befallen the chrome chassis, it was obvious a new power supply and chassis was in order. Also, I decided to do a new cabinet and more modern chassis, because while the ST-70 is a fine sounding machine and the most popular tube amplifier kit in history, it did excel in one other area - UGLY!
NEXT ---> Page 2, the circuitry.