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    Voltage chart in original Stereo 35 manual...

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    Voltage chart in original Stereo 35 manual... Empty Voltage chart in original Stereo 35 manual...

    Post by Guest Tue Aug 02, 2011 12:49 pm

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    Last edited by PeterCapo on Wed Dec 02, 2020 1:15 pm; edited 1 time in total
    Roy Mottram
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    Voltage chart in original Stereo 35 manual... Empty Re: Voltage chart in original Stereo 35 manual...

    Post by Roy Mottram Tue Aug 02, 2011 1:59 pm

    Peter,
    you are correct! The two halfs of the circuit are identical and thus the voltages should be identical.
    My guess is the tech who wrote the manual or took the voltages had tubes that were conducting slightly differently (internal resistance)
    and so he just wrote down the actual voltages he had. Let's call it 225v +/- 10v, huh?!
    Also, BTW, your other email question about bias, the 13.5v across 100 ohms common cathode resistor is 33.75ma per tube
    (assuming they are all drawing exactly equal current).
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    Post by Guest Tue Aug 02, 2011 5:06 pm

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    Last edited by PeterCapo on Wed Dec 02, 2020 1:16 pm; edited 1 time in total
    Roy Mottram
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    Voltage chart in original Stereo 35 manual... Empty Re: Voltage chart in original Stereo 35 manual...

    Post by Roy Mottram Tue Aug 02, 2011 7:58 pm

    try putting a 1K resistor (1/2w or 1w) in parallel with the 100 ohm resistor, that will knock it down to 90.9 ohms and based on your current voltage reading that should bring the bias down to 13.5 volts. Hopefully your tubes are well matched as in stock Dynaco amps if the tubes aren't matched or don't wear out evenly one tube can pull alot more current than the other and you never really know unless you mod the circuit so each one (or at least each pair) has it's own cathode resistor.

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