Crack with tube rectifier

[Giordano]

Hello,

I'm wondering if any of you tried to run the Crack with tube rectifier instead of diodes? I know it is quite a significant mod, needs a new transformer with two secondary (or 4 in total, 2 HV and 2 filament heating), but, in speaker amps it makes a big difference. Would it help headphone amp? Or, the power is so much lower that it does not matter that much? (as we also do not need a choke).

Thanks!
JG

 

[Paul Birkeland]

Tube rectifiers have some pretty serious current limitations and when you have the 6080 output stage drawing somewhat substantial current and you need a good amount of filter capacitance, this becomes extremely taxing on a tube rectifier.  I suspect you could get away with a full wave rectified power supply with a pair of 5AR4s in parallel or some big damper diodes and maybe get away with it.

For what it's worth, the qualitative difference between solid state and tube rectifiers for us over the years has always leaned towards solid state sounding/working a little better.  These performance advantages were also realized in vintage receivers and amplifiers.