How does the amp sound to you? That's important too. Bear in mind that with a cathode-biased Class AB amp, as the amp works harder and more current starts to pass through the power tubes, the bias voltage rises, automatically biasing the tubes colder. So it tends to self-compensate. Also as you go to larger cathode resistor values, the power tubes are getting biased colder at idle, which means that when the amp's working harder, including on transient peaks, it's possible for the power tubes to starve, which will make for some rough sounding distortion. It will also make the amp more likely to suffer from the infamous 18W buzz problem, described and analysed by Paul Ruby. Very large power tube cathode caps (1000uF to 2200uF) can help prevent that, or in worse cases, Paul Ruby's fix using zener diodes.
_________________ Great tones come in small glass jars!
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