• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

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Simple tetrode SE amplifier

Simple tetrode 6Ж4-6П3С SE amplifier
 

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This is a small cheat because I have posted this amp before, but now it has new output transformers, Plitron PAT 3050, (far left in the picture, 14.5# ea.!) it feels like a whole new amp!

I had no idea what I had been missing.

It is a simple circuit with lots of iron (12 transformers per mono block, most of them underneath and tucked away, all to keep a very low DCR) and only 1 resistor and one cap in the signal path. The PSU is extraordinary, now the output transformers are ;-) - the rest is quite conventional. It's a 12bh7 driving a 46. Heaven :))
 

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It is a simple circuit with lots of iron (12 transformers per mono block, most of them underneath and tucked away, all to keep a very low DCR) and only 1 resistor and one cap in the signal path. The PSU is extraordinary, now the output transformers are ;-) - the rest is quite conventional. It's a 12bh7 driving a 46. Heaven :))

Impressive build jdg123!

From your post, it looks like it's well worth the money - enjoy! :)
 
Wheatfield HA-2 OTL headphone amp clone with DC heaters. I'm not happy about the 6.6mVpp of power supply ripple because I can just hear it. I'll try and fix that later. Besides that, the amp sounds FANTASTIC.
 

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Yes! 18 watts to be exact. The spec sheet for the 50W resistors claim they can dissipate 22W free air. I mounted them with a thin layer of thermal compound against the aluminum chassis which is now acting as a huge heatsink. The case does get VERY hot. Temps around the case settle at around half an hour of operation.