i am not a fan of too many stages in an amp....
It is still a Williamson circuit, if you minus the cathode follower stage. You asked if the 12AU7 can be replaced with a 12AY7 and the Altec 1520T gives an example that can be done, not suggesting you to copy the circuit.
I understand the purist standpoint of aversion to multi-stage circuits. I don't see a problem if two stages are direct coupled, which I treat it as a single unit as one stage is dependent on the other for bias. Personally, I'm not a purist. I like colorations as long as noise is not added. By the way, the Altec 1520T is great sounding amp that is transparent and accurate.
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the reason for my aversion is you end up with too many coupling caps...
but i can surmise that the grid are happier being driven by the cathode instead of the plate side where impedance are higher...
today there are other ways to do such things...
my theory is if the open loop of the williamson is higher by using the 12ay7 instead of the 12au7, then open loop will be higher and so addition of global feedback gives better margines....that is what i am interested in...
but i can surmise that the grid are happier being driven by the cathode instead of the plate side where impedance are higher...
today there are other ways to do such things...
my theory is if the open loop of the williamson is higher by using the 12ay7 instead of the 12au7, then open loop will be higher and so addition of global feedback gives better margines....that is what i am interested in...
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