blowing amp?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by noctilux1, Sep 4, 2005.


  1. noctilux1

    noctilux1 Member

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    Looking for correct information. Is it possible to blow an amps transformer using some of the boost pedals on the market today? I just want to make sure I don't blow any of my old amps using several boost pedals and hitting the front end of my amp really hard. Currently using Les Paul into several drive units into an old 50 watt Park head. I don't want to blow the output transformer.
     
  2. TheAmpNerd

    TheAmpNerd Member

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    Anything is possible, but more then likely it would be down
    stream from the real culprate (sp). Several drive units???
    Probably not the best for this nice amp.

    If the amp is healthy and has good tubes and fresh electrolytics
    and a rock solid output selector switch you will probably be fine.

    However, if you are really looking for so much drive why
    would you want to subject your vintage 50 watt Park
    to this?

    Depending on how much boost, you will probably go
    through pre amp tubes pretty regularly.
     
  3. noctilux1

    noctilux1 Member

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    AmpNerd, thank's for your response.
    I like several boutique drives because they sound so good when you mix them. I am not always in a situation where I can run the Park very loud, so I boost the front end to get a more overdriven (I like it just on the edge of break-up with each pedal) sound at lower volumes. It sounds really good, I just want to know if harm will come to the amp, like the output transformer. The amp is all stock and I want to keep it that way. Those KT88's sound good with just a bit of drive in front. With a chain of drives, it's a beautiful mix.
     
  4. TheAmpNerd

    TheAmpNerd Member

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    No problem,

    What pedals are you running in front. Sounds like you aren't
    abusing it, which is good. I have to ask cause some folks will
    max out their OD pedals to get buzzsaw gain. Fine if that is
    what you want, but why waste an old vintage amp to get it.

    If wierd stuff starts happening, get it checked quickly.
    Probably pre amp tube first, When your tone goes dull
    and lifeless probably a power tube change. Also
    save for a cap job on the amp too. Better to have good
    caps and good tone than have parts and trannies frying.

    What year? How often do you play it? How loud?

    When it starts to go, you'll know. Don't fool around and
    get it to a tech. Save for tubes and caps.

    Good luck, enjoy and take care of it.
     
  5. noctilux1

    noctilux1 Member

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    AmpNerd, thank's again. It's a '67 head. I run the volume around 2. I have 5 amps and usually play every night. I try to rotate the amps to keep the caps up to speed. I run mullard, amperex, birmar, telefunken and a few odd ball preamp tubes. The power tubes vary. I don't have quite the money for high-end power tubes. I live close to KCA, so he is the man for me with tubes. A great guy.
    Thank's again for your help on the output transformer. I want the amps to last forever. It's taken a long time; for me, to put them together.
    It's not just music, it's therapy.
     
  6. drbob1

    drbob1 Silver Supporting Member

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    It's not the distortion that might hurt the amp, it's the total power going thru the OT and heating it up. Most of those Marshall built amps seem pretty happy running full out, but an OD can increase the duty cycle (the amount of time the tubes are conduction full power, and consquently the rapidity with which the magnetic field has to get from full - to full +). I'd guess a full square wave fuzz might increase it as much as 1.4 times (so output of a 50w amp, which is probably 80w at full bore, might go up to 120w worth of stress-John I stand to be corrected on this...). OTOH, running the amp on 2 or 3 it's putting out less than 20w, so you've got plenty of spare capacity. On another note, adding ODs doesn't necessarily add volume, gain or stress. Often putting one OD or gain pedal thru another smooths out the sound of the first-you get more compression but not more distortion. This is especially true if you run a fuzz into an OD-the ODs going to round off the square wave shape of the fuzz. This is NOT true with the Zvex machine which adds wierd stuff to the wave shape in between the peaks-and could REALLY kill an overstressed OT I guess... Also EQ makes a huge difference, a lot of bass will add a lot more energy than a lot of treble.
     
  7. TheAmpNerd

    TheAmpNerd Member

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    Thanks Bob.

    Me thinks that is very good explanation.

    I haven't looked at a Zvex, are you talking
    distortion/fuzz or the little amp?

    Looking into my crystal ball:

    Noctilux, I see Genelex in your future!
     
  8. hubert

    hubert Member

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    as long as you are both consenting adults...
     
  9. drbob1

    drbob1 Silver Supporting Member

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    The Zvex Machine pedal-creates distortion on top of distortion, ugly by itself but a thing of beauty combined with another fuzz...
     
  10. noctilux1

    noctilux1 Member

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    drbob1, thank you for the information. I don't want to blow the original OT. I was looking at the ZVEX SHO pedal. I think maybe that little pedal might be too much when put together with my other units. I'm going down to Action Guitar (near me) and try out a Xotic BB. That pedal has alot of power too...... I'll just try it and see.
    AmpNerd, your crystal ball is not clear, no Genelex for me unless Lotto. Money is tight. It would be nice, some day, to hear what Genelex KT88's sound like.
     
  11. drbob1

    drbob1 Silver Supporting Member

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    Well, again, at a volume of 2 I just don't see how you could hurt it. If you're planning to crank it sometimes I might worry, but not at 2-3. BTW, as a clean boost, the SHO is LESS likely to overload things than either a square wave fuzz or a booster that puts a lot of energy into sounds that the speaker can't reproduce (like a treble or bass boost).
     

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