Tube Amp Archive

Ok. I think these comments confirmed what I was thinking - if you want accurate bias measurements you pretty much need to ditch the light bulb current limiter and be VERY careful. The limiter definitely has it’s place when first bringing the amp back up after a mod, or its use use as safety device w...

Hey folks, Always keeping safety in mind, I want to use the light bulb current limiter I built at all times when my amps are on the the bench. However when it comes to setting bias on the power tubes doesn’t it throw things off? I watched an Uncle Doug video on setting bias - he used the limiter wit...

This thread looks abandoned for several years - but was very useful for me. I acquired a ‘69 Bandmaster head recently as a project amp, all original and of course needing some work. I was scratching my head on the bias circuit(s) as it appeared to have both fixed grid bias and a small amount of cath...