Intermittent Loss of R channel [resolved]

suttonri · 503

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Offline suttonri

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on: April 14, 2025, 04:39:22 AM
I think I have this fixed. I would just like to get some explanation about what I observed. When the R channel was out, all *'d resistances, along with B3 read 0. I pushed on the B3 tab and got all resistances normal. I did not check voltages until B3 was restored. At that time all voltages were normal and both channels worked.

What was going on here? The only other thing I did was apply a little extra solder to the capacitor lead at terminal 7. It was a little wiggly.

Thx,
RS
« Last Edit: April 18, 2025, 02:39:59 PM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: April 14, 2025, 04:43:17 AM
By B3 tab, do you mean the tube socket pin on the octal socket? 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline suttonri

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Reply #2 on: April 14, 2025, 09:37:37 AM
Yes, B3 is on the tube socket. Once I nudged it, it's resistance went from zero to spec, and all the *'d resistances went back to spec and my right channel came back. I suppose it's good enough that it works, but I'm trying to learn something here. I don't really appreciate the signal path yet.

Thx,
RS



Offline Paul Birkeland

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Reply #3 on: April 14, 2025, 01:45:46 PM
I suspect there's a loose connection causing you some problems, but it would be very strange to see B3 at 0 ohms, unless possibly there's some debris or untrimmed leads touching things they shouldn't.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline suttonri

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Reply #4 on: April 18, 2025, 08:17:33 AM
It turned out to be the lower resistor on the phone jack. It was not soldered well.

That nonsense with B3 reading 0 resulted in my multimeter taking a few seconds to move off zero. It just happened to get to the proper resistance coincidentally with me giving the tab a nudge.

Close this one out. Love the amp! Right now I'm streaming Qobuz => Chord Qutest  => Crack => Sennheiser HD 800S. Easily an endgame setup.sure there us something better but this will do nicely.

Thx
RS