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5e3 Neil Young sound - destroying tubes? Which output transformer

Discussion in 'Amp Central Station' started by tzurby, Apr 5, 2021.

  1. dan40

    dan40 Friend of Leo's

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    Your input voltage is probably a little low and that is why the b+ and heater voltage looks low also. Set your variac to the point that your heater voltage measures 6.3v AC and your tubes will live a long happy life. Your b+ will also rise slightly which will bring the power tube dissipation up a touch but the amp should be right in it's sweet spot. I highly doubt that the lower incoming voltage or the slightly off spec resistor in your load box had any role in causing the tube to break though. It was likely just an unfortunate occurrence.
     
  2. dan40

    dan40 Friend of Leo's

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    One more thing about the resistor...many meters have a difficult time measuring such low resistances accurately so your resistor may be perfectly fine.
     
  3. tzurby

    tzurby TDPRI Member

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    This is it. Never had such a good sound. Pure Neil Young...

    B+ (measured on pin 8 of rectifier tube, correct?) is now 364V. I put the voltage from the variac at 117V. There are only steps. But this is just the right step. Heater now is 6,3V.

    Thank you all for you help.
     
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  4. marshman

    marshman Poster Extraordinaire Silver Supporter

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    For what this is worth, I have a Fender Excelsior, and early on I did some tube rolling...all US made 1950s 6V6GTs. The further the tubes got from “perfect match” the Neil-ier it got.

    Then, I stuck in a closely matched pair of RCA 6K6GT, pure meltdown tone.
     
  5. dan40

    dan40 Friend of Leo's

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    Happy to hear that it's sounding great again!
     
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