I bought a cheap Chinese SE amp many months ago to drive my tweeters - see this thread: https://www.diyaudio.com/community/threads/chinese-el34-6sn7gt-se-unusual-topology.401911
I disassembled it and fitted separate Glassware PS11 HV power supplies with separate chokes. Without the tube rectifier, the HT increased from about 320 to 368v - same for each channel.
With 330r cathode resistors (bypassed with 470uf) current is 73ma, anode voltage is 346 (22w), screen grid, connected to the UL tap is 355v. Grid resistor is 220k.
I then built an Akido Noval with 12AT7 input/gain stage and 12AU7 for low impedance output. Overall gain was about 12x..
https://www.diyaudio.com/community/threads/akido-preamp-query.408669/
There is no local or overall feedback so I don't think the results are too bad. There is no hum or noise short of putting an ear right against a tweeter.
I disassembled it and fitted separate Glassware PS11 HV power supplies with separate chokes. Without the tube rectifier, the HT increased from about 320 to 368v - same for each channel.
With 330r cathode resistors (bypassed with 470uf) current is 73ma, anode voltage is 346 (22w), screen grid, connected to the UL tap is 355v. Grid resistor is 220k.
I then built an Akido Noval with 12AT7 input/gain stage and 12AU7 for low impedance output. Overall gain was about 12x..
https://www.diyaudio.com/community/threads/akido-preamp-query.408669/
There is no local or overall feedback so I don't think the results are too bad. There is no hum or noise short of putting an ear right against a tweeter.
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