SF Vibrolux to BF

Discussion in 'Amps and Cabs' started by steadygarcia, Mar 14, 2008.

  1. steadygarcia

    steadygarcia Member

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    I'd like to convert my 1973 Vibrolux Reverb to blackface spec. Is anyone familiar with the kit sold for $129 by Dan Torres Engineering? (http://www.torresengineering.com/newvibrevamp.html). It's hard to tell from the description whether this kit converts SF to BF spec. Also, has anyone ever made these mods themselves? How difficult is it? Thnx as always!
     
  2. Catoogie

    Catoogie Senior Member

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    What about your Vibrolux aren't you liking? I think the Silverface Vibrolux's sound amazing and nearly identical to a BF.
     
  3. wgs1230

    wgs1230 Fully Intonatable Silver Supporting Member

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    1. Torres's reputation for shoddy workmanship and mediocre parts is well known, and his more invasive mods devalue amps as a result. Caveat emptor.

    2. From the description, it sounds like basic plate load, cathode bypass and filter cap "upgrades" (along with "rebuilding" the tremolo circuit, very likely unnecessary) which your amp might or might not need, and in any case the price is high and it's not "blackfacing," per se. If you have access to a good tech, get yours checked out to see what, if anything, tests as worn at this point. You might well need a filter cap replacement job, but the whole thing should run you $150-200, depending on where you're located.
     
  4. steadygarcia

    steadygarcia Member

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    Good question actually. I do think it needs some upgrade work replacing capacitors and resistors as it crackles a little from time to time. I figured since it needs a little fixin' it might not be a bad idea to change it to BF specs, since I've read positive testimonials from a number of people who have done so. But as you point out, it does sound good the way it is too!

    I would also like to upgrade from the stock speakers - still have the originals in it. Any suggestions?
     
  5. steadygarcia

    steadygarcia Member

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    Good advice, thanks. I did actually just replace the photo optoisolator since the tremolo wasn't working. Might not be a bad idea to rebuild the tremolo circuit as you suggest, since it's still not working 100%. When I turn the intensity down to a lower value, it seems to go away completely and I need to crank it back up to 10 to get it to come back. Certainly not working as well as the tremolo on my Deluxe. Unfortunately, I live in Fredericton NB where there aren't any dedicated amp techs around. But I guess amp circuits aren't rocket science, and the local electronics guy (who is a guitar player and owns vintage Fender amps himself) should do fine.
     
  6. Blue Strat

    Blue Strat Member

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    Start by getting the amp up to speed as is. Never mod an amp that isn't already operating at it's full potential.
     
  7. wgs1230

    wgs1230 Fully Intonatable Silver Supporting Member

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    First thing, swap in a new tube. If that doesn't take, try putting a meter across the Intensity pot and the 25-25/100k array (to the left of the opto-roach) off pin 8 of the trem tube, see how they test.

    As for the rest... if it sounds good, it is good, you know? Has tonal quality degraded to your ear, and if so, how?
     
  8. fullerplast

    fullerplast Senior Member

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    First of all, realize that you can't really get there from here without a new power tranny. Plate voltage is way higher on a SF. That's one of the biggest differences and since you are already running a 5U4 (or should be!) you can't easily get the voltage down any lower. Component changes by themselves will result in a mutant BF/SF but not a BF sounding amp.

    SF VR's are great sounding in their own right. Just do some routine maintenance and see how it sounds. Filter caps are already stressed to the max so look at those first and upgrade to 500V if they haven't been already.
     
  9. steadygarcia

    steadygarcia Member

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    A 5U4? Is that the rectifier tube? I know my 2 Power tubes are 6L6GC; Preamp tubes are 7025s ... ?
     
  10. slider313

    slider313 Silver Supporting Member

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    +1 Agreed on all points made. I've done a few and they never sound like a true blackface.
     
  11. Rumblefish

    Rumblefish Silver Supporting Member

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    My tech converted my S.F. Vibrolux for half that amount.Parts,labor,everything.
     

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