Dynaco ST-70 original driver boards - early and later versions

Bob Latino

Bob Latino

Admin

Posts: 226
Join date: 2008-11-27
Location: Massachusetts

Dynaco did make an effort to upgrade the cheap brown phenolic board on the ST-70 in the early 1970's by replacing the "brown board" with a much more durable and heat resistant pale yellow fiberglass board. It still had open solder traces but for it's time it was much more durable and a step up from the original brown board. Photos below.

Bob

Earlier phenolic board top

Earlier phenolic board bottom

Later fiberglass board top

Later fiberglass board bottom

fortherecord

fortherecord

Posts: 4
Join date: 2009-05-27
Age: 42
Location: Rochester, NY

From my experience, the traces on the later fiberglass boards were much more susceptible to lifting from the board while soldering and working on them. The traces are not easy to fix or replace once broken either. However, the fiberglass boards did not tend to develop that waxy or gooey film on them, which the older boards seemed to do. I'm not sure what caused that.

1 Dynaco ST-70 original driver boards - early and later versions - photos ... on Fri Dec 19, 2008 12:19 pm

Bob Latino

2 Re: Dynaco ST-70 original driver boards - early and later versions - photos ... on Tue May 26, 2009 10:40 pm

fortherecord