Re: looking for help please with 1964 Trio W-41 stereo valve amp
The circuit says 21V on the heaters, so the output valves may be a bit light on total cathode current (-5%?). The preamp heater supply is a bit of a juggling act with some cathode current (35mA) flowing through the bias resistors for the output valves and only what's left through the preamp heater chain. Fine with all new output valves but will go "off" as the valves age.
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