There are several factors that should be taken into account when choosing a set amp. Yes, the OPT is a big factor, but the power supply has just as much influence. E.g. the last capacitor (CLC) of the filtering has an extreme influence on the sound. By the way, this capacitor should be the main grounding point (stargrounding) of the amp circuit and it has proven successful for me. Please use high quality there, you will be rewarded as promised. the OPT should be generously dimensioned an example. Good power transformer, choke filter ,oil caps and a good OPT are a good path to success.
300b/2a3 opt
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