Will this work? "Mixed" 300B PPP IT

[ppereira]

Will this work? the driver tubes are either ECC99 or 6C45's.... Phase splitter is a Sowter 8920 Transformer. Each phase of the driver stage is IT coupled to two paralleled 300B output tubes via a Lundahl 1660 transformer in SE to SE configuration.

Thanks,

 

[Fuling]

I can´t see any reason why it wouldn´t work, but is there a point in this concept?

 

[cuallito]

Why to be different of course!

 

[ppereira]

No, no point... except for re-using parts that I already have... and to be different off course... 🙂

 

[Eli Duttman]

A cautionary note: with simple cathode bias, the 4 "finals" have to be CLOSELY matched. Obtaining CLOSELY matched quads of 300Bs could be quite difficult.

Implementing Dennis Boyle's combination bias would provide a means by which imperfectly matched tubes are compenstated for.

Use unbypassed 220 Ohm cathode resistors "under" each "final". A bias supply combined with 4X individual bias adj. pots. allows the setting of the "finals" at identical idle currents.