Here's another past amp of mine. Right now it resides on the bench with only the 5Y3 in, and with three wires sticking out - for powering breadboarded circuits. Good for about 400V at maybe 50mA load. Anywho, schematic:
Photo:
- Real nice at night, you can almost read by it! Those heaters get *very* hot. The plates do too, I didn't realize it at the time but I was running way over limits, 300 vs. 120V max. screen for one , and two, 15W dissipation where 10's the limit. No redplate though, at least on reasonably matched tubes.
Bottom:
And yes that PS filter cap is octal!
Tim
An externally hosted image should be here but it was not working when we last tested it.
Photo:
An externally hosted image should be here but it was not working when we last tested it.
- Real nice at night, you can almost read by it! Those heaters get *very* hot. The plates do too, I didn't realize it at the time but I was running way over limits, 300 vs. 120V max. screen for one , and two, 15W dissipation where 10's the limit. No redplate though, at least on reasonably matched tubes.
Bottom:
An externally hosted image should be here but it was not working when we last tested it.
And yes that PS filter cap is octal!
Tim
IIRC, 6W6 is very high current low voltage. Should make a heck of a racket with 150V-200V and a very low impedance transformer, like 1K.
I've sometimes wondered if it was really a triple-size 6V6.
> Those heaters get *very* hot.
Cathode optimized for much higher current than this amp needs.
With 300+V available and the usual 5K to 10K transformer, 6V6 should do very nicely and at a LOT less heater power.
If you are very brave, you could wire 6W6 as Triode and get fantastic damping at 300V 10K load. At least until your screen grids got tired of the abuse and shorted the whole thing out.
Are you saying 6V6 sounds better (in this design) than 6W6? I've wondered about using 6W6 in a low-Z amplifier but never saw one used as hi-fi audio. Shouldn't be bad, but hard to guess how "good" from the specs.
I've sometimes wondered if it was really a triple-size 6V6.
> Those heaters get *very* hot.
Cathode optimized for much higher current than this amp needs.
With 300+V available and the usual 5K to 10K transformer, 6V6 should do very nicely and at a LOT less heater power.
If you are very brave, you could wire 6W6 as Triode and get fantastic damping at 300V 10K load. At least until your screen grids got tired of the abuse and shorted the whole thing out.
Are you saying 6V6 sounds better (in this design) than 6W6? I've wondered about using 6W6 in a low-Z amplifier but never saw one used as hi-fi audio. Shouldn't be bad, but hard to guess how "good" from the specs.
Yea, this amp was at the time when I put two and two together and - it works? fine for me...
It would make a kick-*** amp if I put a 0C3 on the screens and had a lower-Z OPT. The OPT that's in there came from a PP 6V6 PA amp which claimed 25W output.. at 400V supply class A! Can you say red-plate...
Tim
It would make a kick-*** amp if I put a 0C3 on the screens and had a lower-Z OPT. The OPT that's in there came from a PP 6V6 PA amp which claimed 25W output.. at 400V supply class A! Can you say red-plate...
Tim
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