jake wrote:My tube pre recently failed (Dyna PAS3)...
What failed in the PAS? Any mods/updates? In my experiance the usual point of failure in a PAS is the selenium rectifier in the heater supply. Unfortunately in the stock PAS, which has no power fuse, the failed heater supply usually burns out the power transformer. Minimum mod for a PAS is a pair of modern diodes to replace the selenium rectifier and a 1 amp regular blow fuse in the power line. "Been there, done that have the tee shirt" as the saying goes.
There a number of web sites out there with PAS updates and mods. Even replacment transformers, if you need one, are not that expensive.
By the by the, ST-70 has a selenium rectifier in the bias supply. REALY reccomend changing that out and there are a number of parts kits out there for that. Think about one of the kits to replace the PS quad cap at the same time too.