WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
The noise gets amplified by 60dB too. Every guitar amplifier I've ever heard has had audible hum from across the stage. And amplifying then attenuating gives you a headroom problem too.
Hum is a different issue from noise. Noise is nearly the same whether you use passive or active tone controls; putting the gain inside a feedback loop doesn't buy you any particular noise advantage.
The noise gets amplified by 60dB too. Every guitar amplifier I've ever heard has had audible hum from across the stage. And amplifying then attenuating gives you a headroom problem too.
