I have a very strange problem indeed.
I built Kevin Gilmore's CFA3 amplifier, the I added Kevin Gilmore's GRLV linear supply to power it.
When I power the amp from a cold start, a high-frequency, almost whistle-like sound shows up on the output. It las a few seconds (longer if it's cold, less if it's hot) and then goes away. While that sound is heard, I can make it go away by touching the 4-pin XLR output socket.
Once the amp has been running a while, I can power it off, wait a couple of minutes, and power it back up with no noise of any kind.
I think this strange noise didn't come with the previous power supply.
So, quite a few clues, but none of it makes sense to me.
Any wizard can school me on that one?
I suspected oscillation, transformer ringing, and various other things, but I can't convince myself they could be valid reasons.
I built Kevin Gilmore's CFA3 amplifier, the I added Kevin Gilmore's GRLV linear supply to power it.
When I power the amp from a cold start, a high-frequency, almost whistle-like sound shows up on the output. It las a few seconds (longer if it's cold, less if it's hot) and then goes away. While that sound is heard, I can make it go away by touching the 4-pin XLR output socket.
Once the amp has been running a while, I can power it off, wait a couple of minutes, and power it back up with no noise of any kind.
I think this strange noise didn't come with the previous power supply.
So, quite a few clues, but none of it makes sense to me.
Any wizard can school me on that one?
I suspected oscillation, transformer ringing, and various other things, but I can't convince myself they could be valid reasons.