Power Amp 40-50 Watts with 4 5881s

[mwelch55]

I got a good price on a power transformer with specifications 300-0-300 270ma 5V 3A & 6V 9A.  I was wondering if I could design a power amp with this trasformer so that 4 tungsol 5881 installed will give me around 40-50 watts?

I love the sound of the tungsol 5881 reissue.  The problem with that tube is that you can't put two of them into a normal 50 watt amp because the voltage is too high.  The tungsol 5881 is happier at a lower plate voltage.  With secondary voltage at 300-0-300, I should be able to get around  400vdc. I love the way my previous amp sounds with 2 tungsol 5881s with a 6.6K OT and around 380-400 volts on the plate. In that amp I get around 20-25 watts.  That arrangement is my favorite power amp.

I was hoping to do the same thing only around twice the power and I am hoping to get a similar tone as with 2 5881s.  Does this seem like it will work as I expect it to?

Mike

[PRR]

Wasn't the first 5F6a 40 Watts on two 5881, around 400V and 4k load?

[DummyLoad]

Wasn't the first 5F6a 40 Watts on two 5881, around 400V and 4k load?

schema states 432V. i don't imagine that 32V is going to make or break 5881, even the current production stuff.


--pete

[jjasilli]

Comments.  I like the idea of 4X 5881's to take advantage of the hi current handling of this PT's HT supply.  Should yield about 35W.  Personally I would drop about 100V with a combination of a bucking tranny + a large (inductive) power resistor. 


A 5U4 rectifier should work; and help drop some B+.


The hi current heater supply calls out for creative use of small bottle tubes.