• 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.

audio note P1SE improvements

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I have just picked up the P1SE for next to nothing as it was not working 'properly' but the tranformers alone were worth it. Switch - on revealed an unlit ECC83. I replaced this with some non descript unlabeled orphan and it worked. It worked well, but too much gain. Clipping starts with the volume knob at 11 o'clock with about 6W output. It is 2 x EL84, russian equivalents in parallel SE pentode. I think the drivers are SRPP configured. So I need to find a good pair of something to replace the ECC83's which I don't like. There is about 285V B+ available. Also I think I should be getting closer to 10W. Any suggestions for an improved front end and anything else that might help. The caps are old and nothing special. I will replace the cathode ones with Rubicon ZL for a start and also the volume pot which is a real cheapie and is scratchy. I have read good things about PEC moulded carbon pots. The amp is probably about 8/10 years old and I wonder about the quality of the russian valves. Should they be replaced and if so what with. I would look for something not too expensive but still with great sound. JJ EL84 perhaps. If any body can link me to a schematic it would help.
Regards
 
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