Modding a Bugera V22

Discussion in 'The Squawk Box' started by Asdain, Jan 31, 2012.

  1. Asdain

    Asdain Senior Member

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    Hey Guys,

    i plan on modding my little Bugera V22. Mainly the OD section needs some tweaking.
    here is a schematic of the AMP:

    [​IMG]


    I'd like some Input on my Ideas and maybe someone has more Suggestions as well.

    I was planning the following points:

    0. change the Bright Input to work more like a bright boost instead of a bass cut.
    1. Raise Preamp Voltages
    2. Increase Clean channel Gain
    3. Rebuild the OD section, cold stage - hot stage, both with big grid stoppers
    4. Increase output from the OD section
    5.(Open the local feedback of V2b ?)
    6. High Grid stopper for Cathodyne PI (!!!!!!!!!!!)
    7. Slight changes to the Tonestack

    Here is a little beta version of some mods i am plannning, just to see the direction in which this is going. i marked the changed things with lots of !!!'s, messy i know, but i haven't found a way to change colors in eagle yet..

    [​IMG]

    PS: The reference schematic was drawn by netbear on the tubetown forums. I do NOT have other Bugera schematics
     
  2. Razzle

    Razzle Senior Member

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    I'd be very interested in what you decide, and some sound clips on the differences. I love my v22.
     
  3. Asdain

    Asdain Senior Member

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    so far the only change i made is i put in a Jensen C12Q Speaker that was originally intended for my current DIY build. It gives the Amp a more round and balanced sound. The original Bugera Speaker was not bad though, just a little bit too much bass and a slightly dull top-end.

    tube changes will follow too (probably 2x Tung Sol 12ax7 RI, 1x Sovtek 12ax7LPS and JJ or EH EL84)
    but the chinese ones do their job quite well actually and i will try to shape the sound with the circuit changes first.
     
  4. fly a vee2

    fly a vee2 Junior Member

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    i would love to try some of your proposed bugera v22 mods. the brite input mod and increasing gain on clean channel are especially interesting to me. i do not read scematics...but the v22 has all the resistors and caps , etc labeled. so perhaps you might take pity on the ( electronically challenged ) like me and tell us which # part to replace with what different value. done that sort of thing before with good results on blues junior.wnuld be grateful for any help.
     
  5. Syrus

    Syrus Senior Member

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    Just a heads up but, you do realise that purple denotes sarcasm? :naughty:

    Tube swap is an easy reversible mod. Mind the bias of course.

    I personally am more keen on experimenting with AlNiCo style speakers.
    Good to hear that the C12Q gave it some more sparkle, however speakers break-in and they get a tad more mellow, so you might lose some of that top-end in a while.

    The 7025 also gives great results in most amps I've tried in the past. Might be worth to take a look at one of those. I've had the best experiences with TAD 7025 tubes, price-performance wise.
     
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  6. wiesl

    wiesl Junior Member

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    Removing the capacitor C16 isn't a good idea because the Feedback network is DC coupled then. Therefore bias point isn't correct because a transformer is between.

    Didn't have any detailed look/analysis at the other mods.

    Did you already mod your amp?

    BTW: Does someone know either the Range of the BIAS potentiometer or the value of the BIAS potentiometer in kOhm?

    Thank you.

    Wiesl
     

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