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  1. Maybe the board 1 ohm cathode current sensing...

    Maybe the board 1 ohm cathode current sensing resistor/s have drifted up in value a bit. Perhaps following a tube short incident.
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    Yes, the 2 that Iíve worked on had 5Y3. The...

    Yes, the 2 that Iíve worked on had 5Y3.
    The chassis holes need opening out a couple mm in order to accept many modern tubes.
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    It should be feasible to identify if gain is...

    It should be feasible to identify if gain is being lost somewhere along the signal path without a scope, as long as the meter is reasonable. Need some sort of signal generator though, so it would...
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    What tools do you have available, eg multimeter,...

    What tools do you have available, eg multimeter, sig gen, scope?

    As there was a 12AT7 in there, it may be that other changes were made to further reduce gain.
  5. And, for clarity's sake, to state it explicitly,...

    And, for clarity's sake, to state it explicitly, that includes their 0V common connections to the chassis ground, as well as their regular signal path connections.
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    Please consider that all I can know about your...

    Please consider that all I can know about your particular amp is what you have written, eg -



    One last time, no, it is not what I would expect. The low preamp gain you describe suggests that...
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    I've tried to be clear in stating my view that...

    I've tried to be clear in stating my view that your amp may not be working as intended, my apologies if you haven't understood that; as such, it would be bad practice to consider modification to it....
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    If you're happy it's all working fine and there...

    If you're happy it's all working fine and there are no actual faults that require resolving, then that would seem to be that, and it's time to get on with enjoying your new amp :thumbsup:
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    The queries raised in post 1 might well indicate...

    The queries raised in post 1 might well indicate malfunction, hence my response. Unfortunately, after a couple of decades use, I find that some pcbs need reflowing in order for the integrity of their...
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    The Kinman site has some good strat set up tips...

    The Kinman site has some good strat set up tips that I find very helpful (and refer back to occasionally) https://kinman.com/perfect-guitar.php specifically...
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    Sorry, you mentioned a few issues (eg...

    Sorry, you mentioned a few issues (eg insufficient preamp gain for noticeable overdrive, master vol having little effect) that may indicate circuits not working as intended, which may well be due to...
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    V1 in the preamp is the phase splitter. My...

    V1 in the preamp is the phase splitter.

    My experience with these amps is that theyíre plagued with dry joints; itís best to reflow the pcbs.
  13. Speaker polarity is a variable - there was no...

    Speaker polarity is a variable - there was no regulation / standard / convention that manufacturers had to comply with. These days the 'positive voltage produces positive pressure' convention has...
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    When I looked into the lead hazard, it was mainly...

    When I looked into the lead hazard, it was mainly down to skin contact leading to ingestion; inhaled lead in the solder fume seemed a non-hazard, rather the issue with fume was occupational asthma,...
  15. Are the signals from the amps in opposing...

    Are the signals from the amps in opposing polarity? As when both together it seems quieter.
    The virtual TR's reverb quality seemed better than any real one than I've heard, no trace of 'boing', more...
  16. It may be that when he came up with the system...

    It may be that when he came up with the system (eg early 1970s) master volumes weren't common at all. And with regular preamps, eg Marshall 1987, a type 4 master vol doesn't have sufficient gain...
  17. Just to note that the original 470 ohm V3 cathode...

    Just to note that the original 470 ohm V3 cathode bias resistor may have drifted up in value, well above its tolerance limit, thereby mitigating the hot bias condition somewhat.
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    Yes, I've emailed G4M and Belcat but don't hold...

    Yes, I've emailed G4M and Belcat but don't hold out much hope.
    The build quality is poor, dry joints on the pcb, very disappointing for such a new amp.
    It's a shame, as the amp sounded pretty good.
  19. Apologies, I assumed most would be familiar with...

    Apologies, I assumed most would be familiar with Ken Fisherís The Trainwreck Pages https://robrobinette.com/images/Guitar/Trainwreck/The_Trainwreck_Pages_searchable.pdf
    I think that Aspen Pittmanís...
  20. Iím not sure that Helmholz meant it like that;...

    Iím not sure that Helmholz meant it like that; rather the 470 ohm cathode bias resistor resulted in much higher idle current and dissipation, of the tube and transformer.

    Assuming that there are...
  21. Master vol?

    Master vol?
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    Belcat 35RG Schematic Request

    I'm looking at this amp https://www.gear4music.com/Guitar-and-Bass/35W-Electric-Guitar-Amp-with-Reverb-by-Gear4music/7H8 for a friend.
    A schematic would be very handy to help work out exactly where...
  23. Grid stoppers still on V3? Is there still a...

    Grid stoppers still on V3?
    Is there still a master volume control?
  24. From the link I think you aren't putting...

    From the link

    I think you aren't putting sufficient weight to the 'generally speaking' bit ;)
    This is probably the original schematic for your amp...
  25. The 500V is across the cap, not the dropper...

    The 500V is across the cap, not the dropper resistor feeding it.
    The steady state Vdc across the resistor will depend on the current being drawn by the circuits it is feeding, eg phase splitter and...
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    Thereís a light blue MF style resistor, may be...

    Thereís a light blue MF style resistor, may be 2W, between R19 and R49; the gloop is clear at one end if it, dark at the other?
    And itís dark around the tab connector (red wire, upper right of...
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    Itís weird for the gloop used to mechanically...

    Itís weird for the gloop used to mechanically secure parts to the board to be 2 tone.
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    I donít think it feasible to visibly discern 60Hz...

    I donít think it feasible to visibly discern 60Hz oscillation on a voltmeter needle?
    Rather the fluctuations seem more likely to be at a somewhat lower frequency.

    HT means high tension, aka B+...
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