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John10b · 12th Jul 2019, 7:14 pm

Thank you all for your feedback. I now have another question, which I feel I shouldn’t need to ask, but I’m going to anyway, after all this is what the forum is all about.
It now concerns the two EL 42 , both made by Mullard.
I noted that there is a big difference in the working temperature between the two valves ( 80 degrees C and 28 degrees C) which after checking bias voltages and cathode current ( 29 mA/ valve) puzzles me.
The amp is working correctly, as far as I can determine, no distortion or hum.
Without going into further detail why would there be such a big difference in the working temperature of the two valves in what appears to be an amplifier that is working correctly ?
Cheers
John

12th Jul 2019, 7:14 pm	#40
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,887	Re: Voltages on ECC83 in BlackBox Thank you all for your feedback. I now have another question, which I feel I shouldn’t need to ask, but I’m going to anyway, after all this is what the forum is all about. It now concerns the two EL 42 , both made by Mullard. I noted that there is a big difference in the working temperature between the two valves ( 80 degrees C and 28 degrees C) which after checking bias voltages and cathode current ( 29 mA/ valve) puzzles me. The amp is working correctly, as far as I can determine, no distortion or hum. Without going into further detail why would there be such a big difference in the working temperature of the two valves in what appears to be an amplifier that is working correctly ? Cheers John