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ms660 · 18th May 2021, 12:53 pm

The problem is that I don't fully understand what it is you're doing but at the moment I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak?

If that's the case then the only part of the amplifier circuit that should alter when changing from record to playback is the feedback circuit between the two triodes, that's switched by relay contact W1, in playback the different components that are switched in are C10, R6 and R9, it might be worth checking C10 for leakage.

That's assuming that contacts B1 or B2 are not in the closed position due to whatever reason when playback is selected.

Lawrence.

18th May 2021, 12:53 pm	#56
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Grundig tk 24 The problem is that I don't fully understand what it is you're doing but at the moment I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak? If that's the case then the only part of the amplifier circuit that should alter when changing from record to playback is the feedback circuit between the two triodes, that's switched by relay contact W1, in playback the different components that are switched in are C10, R6 and R9, it might be worth checking C10 for leakage. That's assuming that contacts B1 or B2 are not in the closed position due to whatever reason when playback is selected. Lawrence.