Silverface tremolo speed range???

Discussion in 'Glowing Bottle Tube Amp Forum' started by E5RSY, Sep 20, 2020.

  1. E5RSY

    E5RSY Doctor of Teleocity

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    Curious as to what everyone's slowest speed is on these amps. I feel like my Super Reverb is pretty fast, even at its slowest setting. Mine is about 220 per minute.

    If you're so inclined, I'd be interested to know what your slowest trem per minute speed is. Just count for 15 seconds and multiply it by 4.

    Thanks,
    Scott
     
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  2. String Tree

    String Tree Doctor of Teleocity Ad Free Member

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    I'm the wrong guy to ask about specifics but, the last time I had my Silverface Vibrochamp serviced, it had the tech change out a Capacitor that made it slower across the entire range.
    HE knew which Cap to change, I did not!

    Your Amp should be no different.
     
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  3. Ten Over

    Ten Over Tele-Holic

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    3.55Hz
     
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  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Yup - you can swap out 1 or 2 caps in the trem oscillator to slow it down. I ALWAYS want it slower than stock.
     
  5. schmee

    schmee Doctor of Teleocity Silver Supporter

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    There are normally 3 caps tied to your tremolo circuit. two .01s and one .022. Pull a .01 and replace with a .022uF. That will slow it down. You will also find a 1M resistor in that circuit, a 220K will make the tremelo stronger. That will highly increase the intensity. or you can use a 470K for a bit more only.
    may be something wrong with the amp if it's mostly fast tremelo though. Check that 1 meg resistor, maybe it's out of spec high.
     
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  6. tubegeek

    tubegeek Friend of Leo's

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    There's no need to SWAP anything. Caps add in parallel, it's about a two minute job to put another .01 in parallel with one of the ones that're already there. Not slow enough? Do the other one.

    I've done this on my Ampeg Rocket and in my homebrew Supro. Works great. Easily reversible.
     
  7. E5RSY

    E5RSY Doctor of Teleocity

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    Lots of great advice. Thanks.

    Still looking for some numbers, though. Anybody?
     
  8. Ten Over

    Ten Over Tele-Holic

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    See if you can replicate these results:

    Tremolo Resistors.png
     
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  9. tubegeek

    tubegeek Friend of Leo's

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    As mentioned above, a nice slow trem will come from 10/10||10/22 nF or even 10||10/10||10/22 nF. (10||10 is 10 paralleled with 10 more. 10 nF = .01uF.)
     
  10. trancedental

    trancedental Tele-Meister

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    Uncle Doug changes the trem speed on a Vibro Champ, by adding a cap in parallel. 36mins into his video.

     
    Last edited: Sep 21, 2020
  11. Ten Over

    Ten Over Tele-Holic

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    3.33, 3.78, 3.61, 3.81, 3.74, 3.71, and 3.75Hz. The speed is a function of the resistors and capacitors in the phase shifting network. The different 12AX7's and supply voltages have a very minimal impact on speed. All of the above speeds have the same .022uF/3.1M, .01uF/1M, and .01uF/1M CR combinations. The differences in speeds are due to the deviations of the components from their nominal values.

    Lowering the slow speed also lowers the high speed. Mods to the stock setup lower the high speed more than the low speed, so you sacrifice range when you lower the low speed. What particular component you alter makes a difference in how much the range gets reduced. If you were to double one of the three capacitors, the .01uF one closest to the grid will result in the least reduction in range.
     
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  12. avspecialist

    avspecialist Tele-Meister

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    I like the parallel.01 mod. I use the tremolo on some older Beatles stuff and some Doors. I might try that resistor mod for more intensity
     
  13. Linkjr

    Linkjr Tele-Meister

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    @schmee the 1m resister you mentioned , would changing this also increase trem intensity in a vibrochamp trem circuit?
     
  14. schmee

    schmee Doctor of Teleocity Silver Supporter

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    Hmmm, I'm unsure. Maybe it would be the 68k resistor on the VC? Hopefully someone else will chime in on that.
     
  15. schmee

    schmee Doctor of Teleocity Silver Supporter

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    BTW, I got this wrong if you are applying it to other amps. The 1 meg noted is for a Princeton BF/SF style amp. I think that resistor on the larger amps is the 10 meg on the leg of the opti-ocillator.
     
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