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  1. Values are perfect. Your OT won't cause the...

    Values are perfect. Your OT won't cause the redplating.

    Please post schematic and measure screen resistors/voltages.
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    Inductors don't like switching signals, so they...

    Inductors don't like switching signals, so they react with counter-EMF, thwarting the measuring current. This in turn may drive the meter crazy.
    Shorting the coupled secondary essentially shorts...
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    Closed or semi-open? This makes a lot of...

    Closed or semi-open? This makes a lot of difference. My explanation above was for closed cabs only.

    In comparison to a closed cab an open cab may significantly extend bass response. Also cab type...
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    Many DMMs have problems to correctly measure DCR...

    Many DMMs have problems to correctly measure DCR if it hides behind a large inductor like an unloaded transformer.
    Short the secondary while measuring primary DCR for a reliable reading.
  5. For reliable readings short the secondary while...

    For reliable readings short the secondary while measuring primary DCR. (If it works I'll try to explain why.)
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    Closed (non-vented) cabinets considerably...

    Closed (non-vented) cabinets considerably increase the bass resonant frequency of the speakers. While sound will be strong at the resonance, sound level rapidly drops below the resonance.
    E.g., a...
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    While this is my all time favorite self-adjusting...

    While this is my all time favorite self-adjusting wire stripper:
    57134

    ..nothing beats these (see post #30) with Teflon insulation:
    57135
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    If B+ is the same the PT secondary voltage must...

    If B+ is the same the PT secondary voltage must be higher with the 5U4. The difference is the slow heat-up of the GZ34 (as opposed to the 5U4), which would prevent the turn-on hum surge.

    Also the...
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    Yes, voltage divider sets base voltage and base...

    Yes, voltage divider sets base voltage and base voltage defines emitter voltage. Seems I misinterpreted.
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    Well the BF uses a GZ34. Can you post the...

    Well the BF uses a GZ34.

    Can you post the B1270 circuit?
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    This can't be directly responsible for the -62V...

    This can't be directly responsible for the -62V at the grids. I think it's the emitter current of Q5/Q6 which drops the voltage across R22/23, R24/25.
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    I think it's a SS PI output clipper before a post...

    I think it's a SS PI output clipper before a post PIMV meant to emulate power tube input clipping caused by grid conduction, which would be prevented by the signal reduction caused by the MV.
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    I'd leave it at that, if it sounds ok. From...

    I'd leave it at that, if it sounds ok.

    From your data I calculate a total dissipatin of 15.2W. As this contains the screen dissipation of around 1.7W, I get a plate dissipation of 13.5W or 112%.
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    Resistor problems will show from actual voltages....

    Resistor problems will show from actual voltages.

    The observed signal asymmetry could be caused by:

    - a non-conducting power tube (including open connection to one side of the OT primary)
    - an...
  15. No reason for DeoxIt, as its no metal or...

    No reason for DeoxIt, as its no metal or electrical contact. A little warm soapy water applied on a Q-Tip should do. Dry with a tissue. Or use isopropanol.
    Use DeoxIt on the jacks, though.

    But as...
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    What are plate and screen voltages both measured...

    What are plate and screen voltages both measured directly at the sockets?
  17. A drop of hot water applied to the outside of the...

    A drop of hot water applied to the outside of the dowel before heating might help to melt the glue. Most glues can be broken by steam.
  18. As you speak of arcing: Has anybody really seen...

    As you speak of arcing: Has anybody really seen an arc?
    I think arcing at a "lowish" voltage of 450V or so would mean poor vacuum. Which tube brands are concerned?

    I re-read Nick's thread on DCCF...
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    I noticed a typo in my post #22 above: Max....

    I noticed a typo in my post #22 above: Max. resistor dissipation in the example should read 10W (actually more like 11W). Power output will be reduced by around 6W and tube dissipation at idle will...
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    Does the amp use a GZ34 or a 5U4 rectifier? I...

    Does the amp use a GZ34 or a 5U4 rectifier? I wouldn't expect a hum surge with the slow heat-up GZ34.
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    Another kind of "tool": 57096 Rohde &...

    Another kind of "tool":

    57096

    Rohde & Schwarz analog real power wattmeter (max. 500W) and true RMS voltmeter (30Hz..10kHz). Principle: electrodynamic cross field dynamometer.
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    Schematic?

    Schematic?
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    Tube pins can be cleaned/scraped by these...

    Tube pins can be cleaned/scraped by these (actually strippers/scrapers for enamelled wire):

    57094
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    57092 Tools to re-align preamp tube pins.

    57092

    Tools to re-align preamp tube pins.
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    57091 Extractable telescope inspection mirror.

    57091

    Extractable telescope inspection mirror.
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    Apart from bad filtering, the scope pics looks...

    Apart from bad filtering, the scope pics looks like half-wave rectification. Do you get full B+ with the new 47 cap? Repetition rate of ripple peaks should be 120Hz. If not check the rectifier...
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    It might make sense to look for external sources...

    It might make sense to look for external sources of magnetic interference.

    You can use a high impedance reverb transducer coil (or a single coil PU) connected to the amp's input as a "sniffer".
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    The difference between the use of resistor(s) and...

    The difference between the use of resistor(s) and zeners is that the resistor increases sag, zeners don't. So if you adjust for equal B+ at idle, there will be more compression and power loss (at...
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