Bias and rectifier tube swap in Tweed Deluxe and Tweed Bassman

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by dallyd31, Sep 17, 2008.

  1. dallyd31

    dallyd31 Member

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    I am looking at both a Tweed Double Deluxe and a Tweed 59 Bassman clones.

    I was wondering if I can change rectifier tubes in either or both to increase or decrease the breakup point. If so, do I need to mod anything or rebias everytime I do it ??? For example from a 5y3 to a 5ar4 in a Double Deluxe to increase headroom or swap a 5y3 into a Bassman to lower the breakup point
     
  2. tlpruitt

    tlpruitt Member

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    Yes, you can change rectifier tubes in both amps.

    You will need to adjust the bias in the Bassman if you change to a different rectifier.
     
  3. dallyd31

    dallyd31 Member

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    Thanks...will changing to a 5u4g or 5y3 in the bassman lower the headroom and make it breakup at more reasonable volumes ???

    If so, other than breakup point, will it change the overall tone a lot....I would like to keep the character the same, just lower the headroom.
     
  4. FrankieSixxxgun

    FrankieSixxxgun Member

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    Couldn't you go solid state for the rectifier if you really wanted it to bust up early?
     
  5. Swarty

    Swarty Member

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    I would not trust a 5Y3 to withstand the current demands in a 2 6L6 amp.
     
  6. tlpruitt

    tlpruitt Member

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  7. GearHeadFred

    GearHeadFred Member

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    These changes are basically effecting the voltage level (That's why you need to re-bias) and "firmness" of the power supply..

    Solid state rectification provide the highest voltage and most firmness, usually equating to tight bass response and maximum headroom. The different tube rectifiers give varying degrees of voltage and firmness (Mike's chart is a good resource).

    Keep in mind that some of the tube recros draw 3A filament, which is more than some power transformers can supply.
     
  8. Uniphasian

    Uniphasian Member

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    For Clark amps, he suggests that the Beaufort (Tweed Deluxe) run a 5y3, but if you want the sound of an old amp running overvoltaged to use a 5V4 or 5AR4 rectifier. His transformers are designed for this, though.
     
  9. dallyd31

    dallyd31 Member

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    So, from reading that article, it looks like it is cool to change on a cathode biased amp like a double deluxe, and you can change in a bassman, as long as you re-bias.
     

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