As earlyer mentioned, show us what you hear. Work backwards, find the wiggle on the output of the dut, then work back towards the input and then the rail. If you can hear it you can find it. When you know the time domain and see the formation on the scope it should be easy to find elsewhere if it exist there.
What about if I use an RC low pass filter in the PSU for aprox. 51kHz with 0,8 ohms and 0,39uF Jensen PIO?
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Isn't hiss, link to YouTube to listen the noise https://youtu.be/ABTbas-JA9o
This noise is only using passive avc preamp.
This noise is only using passive avc preamp.
I had a 12AY7 (6072) new Harmonix tube once that went sounding like that on an amp in a week's time and the importer replaced it to me
I mean I have heard that before from a bad tube. Maybe the bias current went up in some tube or it takes to try replace some even in the second stage? When exactly that noise started? After what rework/mod? Or it just started alone?
The input tubes are normally more suspicious but change for any stage you have to possibly find clues
![WP_20170320_002[1].jpg](/community/data/attachments/547/547367-974bbaf690a5cebb787960cf6c1eaf9e.jpg?hash=l0u69pClzr)
Very toasty rectifiers, I'd have to believe the only place with that much current flowing would be the heater supplies.
I recommend 3A Schottky rectifiers minimum for the sort of load current you are likely to see. Also when you build the new one space them 5mm off the board.
If you are using one bridge to power each channel the peak current is probably several amps or more - even a Schottky might be dissipating more than a 1/2W and conventional silicon over 1W and will get very hot.
(All swag on my part, no calculations involved)
Don't use that board material! 😀
If you are using one bridge to power each channel the peak current is probably several amps or more - even a Schottky might be dissipating more than a 1/2W and conventional silicon over 1W and will get very hot.
(All swag on my part, no calculations involved)
Don't use that board material! 😀