No. I do have a comment: a single pair of EL34 can be pushed to 50W. For the trouble and complexity of the drivers I would optimize the voltage and crank it up to get 75W out of the EL34 quads. I would also use a beefier output transformer to dramatically reduce the distortion before the feedback is applied.
CXPP70-3.5K - 70W, 3.5K
Are you going to build it? I will post an amplifier schematic somewhere 'to make a open source' schematic of some very interesting amplifier I have been playing around for years and never quite finished it. I don't have any formal university knowledge in tubes or electricity, I have an electric college diploma, and some university physics/science, I am not an electric engineer, beside but I avidly read books and built circuits and amps in the last 10 year, I want to go back at it and finish the project. The best I have done is to use multisim and tubecad to draw schematic in a newbie fashion.
My experience with tube amps is that no matter how good the circuit is, it will sound as good as the output transformer. I have found that symmetrical toroid of high quality or lundhal LL1620 of the best quality is a MUST, it will unclog the sound, remove the muffler, improve dynamics and separation of sounds, immediately noticeable. Hammonds and Edcor are OK, but a symmetrical machine winding OT will open new doors. I tried CFB and it is not a panacea, UL way better, the driver stage needs to have stability and enough gain, that's all.
CXPP70-3.5K - 70W, 3.5K
Are you going to build it? I will post an amplifier schematic somewhere 'to make a open source' schematic of some very interesting amplifier I have been playing around for years and never quite finished it. I don't have any formal university knowledge in tubes or electricity, I have an electric college diploma, and some university physics/science, I am not an electric engineer, beside but I avidly read books and built circuits and amps in the last 10 year, I want to go back at it and finish the project. The best I have done is to use multisim and tubecad to draw schematic in a newbie fashion.
My experience with tube amps is that no matter how good the circuit is, it will sound as good as the output transformer. I have found that symmetrical toroid of high quality or lundhal LL1620 of the best quality is a MUST, it will unclog the sound, remove the muffler, improve dynamics and separation of sounds, immediately noticeable. Hammonds and Edcor are OK, but a symmetrical machine winding OT will open new doors. I tried CFB and it is not a panacea, UL way better, the driver stage needs to have stability and enough gain, that's all.
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