I'm about to dive back into my ST-70 after 15 years of happy listening since it's first re-build. The power transformer just got too noisy (not to mention hot!!) and I figured in the name of safety and reliability, I should replace it. I'm going to use the larger PA-060S replacement.
I figured I would replace all the elecrolytics while I'm under the hood anyway.
Currently my ST70 has a Mallory replacement 40-30-20-20 uF @500v cap, with an extra 100uF at 450V axial cap used after the choke, and a couple of Solen 5.1uF film caps as by-passes inside the chassis. I picked up a new 80-40-30-20UF @525, which is almost as much capacitance as the old quad cap with the 100uF axial, but I'm wondering if I should add still more, and if so, how much? Also, the current bias supply is just a 1N4007 diode and two 100uF caps, should I beef this up as well?
BTW, I'm still using the GZ34 tube rectifier, the driver board is a Curcio differential cascode stage with Tesla 6922's, and I'm running the outputs in triode for a whopping 17W/ch.
Any input is appreciated.
I figured I would replace all the elecrolytics while I'm under the hood anyway.
Currently my ST70 has a Mallory replacement 40-30-20-20 uF @500v cap, with an extra 100uF at 450V axial cap used after the choke, and a couple of Solen 5.1uF film caps as by-passes inside the chassis. I picked up a new 80-40-30-20UF @525, which is almost as much capacitance as the old quad cap with the 100uF axial, but I'm wondering if I should add still more, and if so, how much? Also, the current bias supply is just a 1N4007 diode and two 100uF caps, should I beef this up as well?
BTW, I'm still using the GZ34 tube rectifier, the driver board is a Curcio differential cascode stage with Tesla 6922's, and I'm running the outputs in triode for a whopping 17W/ch.
Any input is appreciated.