Recycled PT and OT, suitable for Rocket-type build?

[Dingleberry]

Hi.

I will be starting a rocket type build. I have a recycled chassis and recycled PT and OT. SS rectifier because the absence of 5V heater winding.

OT primary impedance is about 5k5. Would that be ok?
It's from an amp that run 4xEL84 power amp, but a fixed bias and lot higher voltages than we normally see for EL84.

PT is from a Russian stereo amp, Rigonda Bolshoi, that had two 2xEL84 pp power amps and about dozen of other tubes, so it has more than enough current to offer, but voltages are bit on the low side... Feeding 230Vac into 237Vac input gives about 210Vac output unloaded. 230Vac into 220Vac input gives about 225Vac unloaded.

Using bridge rectifier 225Vac would be about 315Vdc unloaded.
If using that 220Vac input and lowering the heater voltage a bit I would probably get something close to 300Vdc when running with tubes.

It is a bit on the low side for Vox/Rocket-type amps thus it's the EL84 data sheet max.

Have you experienced wit lower plate voltages and higher OT primary impedances?

Will it compress/distort earlier because of the lower plate volts?

Or what the heck, shoud I just build It and listen how it sounds...

Info/suggestions/tips welcome.

-T

[dartanion]

That should work fine. The OT is closer to a Liverpool, but should work. The PT should be beefy enough and the voltages are within reason. Give it a go and report back.

[soma_hero]

If it's that beefy it probably has enough high tap current to allow for a voltage doubler without dropping around too much. Then you could use a mosfet to drop however much voltage you want to get it perfect..

[RJ Guitars]

Give it a shot... those specs are close enough to start you off. The Rocket circuit is very forgiving and is itself an iteration of the AC30 that uses a higher voltage. You can tweak with it after the fact. For the output transformer there are rumors that they were wound at 5K anyway. I think if Ken Fischer started with your transformer set he would have built an awesome sounding amplifier.

rj