Rerurn to Romy the Cat's Site
In the Forum: Analog Playback
In the Thread: The last phonocorrector: “End of Life" Phonostage
Post Subject: 834pTPosted by rowuk on: 3/7/2021
Hi Alex,I am sorry, what you claim can not be. No cap is going to separate bass instruments better.
The brilliance of the 834p circuit is that the EQ also uses the miller capacitance of the tubes in a very brilliant way. The power supply caps are very well dimensioned. There is no issue with bass definition or texture with the original or the Thorsten Loesch mod. There is no big current drain on those caps that would need "bigger". Separation of instruments on complex music with a lot of bass sounds bogus to me. I generally only want the big caps early in the power supply and smaller ones for "isolation" between stages. I do not use tube rectification or regulation on the phono corrector. The EAR834p is "soft"enough with MM or MC HO cartridges, but with a proper SUT is wonderful with MC. I am using an Ortofon T30 and an Ortofon Rohmann cartridge.
The output cap is another issue. It is only to prevent DC from getting out. I tried the 12AX7, 12AT7, 12AU7 and 12BH7 for the output tube. The 12BH7 stayed. It had the most grunt with longer interconnects. No change to the cap was necessary - even with 10 meters of interconnect. Using my Shure ERA4 test record, there is plenty of output to 10 Hz. Sure, maybe 1 Hz is theoretically cool, finding a great sounding cap for that will be a challenge.
I have often thought about putting the series output cap (or transformer) at the input of the amplifier so that the interconnects are biased with whatever DC happens to be left over. I believe that this bias is the reason that studios can have miles of microphone cables and still get "reference sound". The phantom power keeps the cables biased.Rerurn to Romy the Cat's Site