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Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

The history and merits of "blackfacing"

Discussion in 'Glowing Bottle Tube Amp Forum' started by theprofessor, Jun 5, 2017.

  1. Indian Joe

    Indian Joe Tele-Meister

    Age:
    69
    139
    May 21, 2017
    Ramona, California, U$A
    Silverface, thanks for that memory. I heard those early BF amps were popular up your way. Surf-town Encinitas was "Boogie-land" because of a dealer there, and some Fender owners were even using Boogie tubes & speakers to 'improve' their amps!??? Go figure!
    There was a much larger, more vibrant music scene around LA, where crowds and amps were bigger. Sound styles were quite different, as well. The 4 x 10 SR was poplular, though, with Strat players in SD. DR & PR have always had a solid following. Like, duh!!?
     

  2. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    Since we're talking silverface Deluxe Reverbs and the like, here are a bunch of gut shots of my '76 DR. Perhaps they can serve as a helpful point of comparison in the discussion, though I think we've established that there really is no "blackfacing" procedure for a SF DR. (I've got no idea why the site uploads the photos in a vertical orientation. Sorry. I don't know how to fix that.)

    IMG_0084.JPG IMG_0086.JPG IMG_0087.JPG IMG_0088.JPG IMG_0089.JPG
     

  3. robrob

    robrob Poster Extraordinaire Ad Free Member

    Dec 29, 2012
    United States
    This is a great thread. I'm loving the oral amp history we're getting here.
     
    theprofessor likes this.

  4. Wish I could add something cool to this thread but I have to admit I was a long hair youngster when most of this was happening. My 74 Pro Reverb (my parents bought it new for me when I was 15-16) was wonderful in my eyes. I thought I had the best amp ever made!
     
    J Hog likes this.

  5. slider313

    slider313 Tele-Holic

    Age:
    60
    916
    Jan 6, 2011
    NC
    What's the value of that replaced phase inverter input cap? It's 1000v and probably polyester film. I've tried a few different types in the pi and, IMHO, ceramic disc just "sounds right." YMMV

    [​IMG]
     

  6. GuitarJonz

    GuitarJonz Poster Extraordinaire

    Mar 16, 2003
    MA
    Not sure if this was answered somewhere in here, but if a SF Fender with master volume is modded as blackface, must the MV be removed to consider it really "blackfaced", or can the MV remain, still getting the BF benefits? I never use the MV anyway, and just leave it on 10.
     
    jman72 likes this.

  7. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    I totally agree. That's really fun!
     

  8. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    I have no idea! This is just how the amp came to me. And by "value," do you mean "what good is it doing?" or "numerical value"?

    Just by reading the cap in the photo, I think it says 0015MF +/- 10% 1000VDC. Does that sound like "a thing?"

    I know very, very little about the insides of amps, and that part stuck out to me as well.
     

  9. Andy B

    Andy B Tele-Afflicted Ad Free Member

    Mar 16, 2003
    Colorado
    Generally I leave the Master Volume as is. Turned to 10 it has a negligible effect on the circuit.
     

  10. slider313

    slider313 Tele-Holic

    Age:
    60
    916
    Jan 6, 2011
    NC
    If it's my amp, I install a high voltage (2000v) .0047 ceramic disc cap there. The silverface circuit value would have been a .01 but I prefer the .005 or .0047.

    http://www.ebay.com/itm/20-pcs-High...pf-4-7nf-0-0047uf-472-2000V-2KV-/391736085508
     
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  11. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    Thanks, slider! What does it do. That is, how does it affect the sound?
     

  12. slider313

    slider313 Tele-Holic

    Age:
    60
    916
    Jan 6, 2011
    NC
    The phase inverter input capacitor regulates the amount of frequency output from the 12at7 that drives the power tubes. The blackface Deluxe Reverb used a .001 and later silverface amps a .01. I prefer a .005 in my original '65. You could also just leave it, if you like the sound of it now.
     
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  13. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    So the smaller value allows more frequency output from the PI to the power tubes, which results in more/earlier power tube distortion? That would make sense, if the BF ran a .001 and the later silverface a .01. If mine is indeed a .0015 (I'm not sure if I'm reading that right; the picture is blurry), then it seems that would be basically the "blackface" spec.
     

  14. Andy B

    Andy B Tele-Afflicted Ad Free Member

    Mar 16, 2003
    Colorado
    .01 cap will pass more lower frequencies compared to a .001. Gerald Weber recommended this to fatten up the sound of BF amps. Personally I replace the ceramic cap with a film cap, value dependent upon what sounds best.
     
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  15. MilwMark

    MilwMark Poster Extraordinaire Ad Free Member

    Apr 29, 2013
    near Arnold's
    Why would a BF circuit need more lows or fattening up?
     

  16. Andy B

    Andy B Tele-Afflicted Ad Free Member

    Mar 16, 2003
    Colorado
    Depends on what the player wants. The traditional .001 value works well in my opinion.
     

  17. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    Same question here. Fat = not articulate.

    That being the case, I want to stick with the lower value (though I still can't tell exactly what I've got; I'll have to look more closely next time I pull the chassis). I don't want more bass. And it's interesting to note, I think, how many folks who play Fenders talk about setting their EQs with all treble (and all mids, if applicable), all volume, and no bass. The recent "famous people's EQ thread that @homesick345 started attests to the ubiquity of such settings amongst many blues players, at the very least. I can always roll of highs, but not so with bass. And more bass in a guitar amp tends to muddy things up.
    RE: Weber: I was recently looking at one of Weber's books in which he has a chapter where he and various other famous techs give tips on how to "juice" your vintage amp. I'm not saying that's what the .01 cap will do, all by itself. But, man, I want the opposite. I want EQ control, voltage down, gain down, etc. In my opinion, things get out of control and boomy and piercing pretty fast. I want to "anti-juice" my amps. That's where I think they sound best.
     
    Last edited: Jun 9, 2017
    jonrpick likes this.

  18. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    Well maybe it was! Do you still have it, by chance?
     

  19. jonrpick

    jonrpick Tele-Afflicted

    Mar 17, 2014
    Marietta, GA
    Professor... I agree wholeheartedly on the heavy bass thing. On my recent build I went with a very non-traditional tone setup to let me dial back the bass for this reason.
     
    theprofessor likes this.

  20. robrob

    robrob Poster Extraordinaire Ad Free Member

    Dec 29, 2012
    United States
    The blackface head cab AB763's, the Tremolux, Band-Master and Showman, use 50% smaller 500pF coupling caps leading to the phase inverter compared to the other amps' 1000pF (.001uF). This was done to reduce bass frequencies into the Fender closed back extension cabs which exhibit extended bass response compared to open back combo cabs. The smaller cap also tends to tighten up the overdrive tone.

    If you play mostly open back cabs and not a lot of overdrive then the .001uF is probably best for you. If you play closed back and/or heavy overdrive the 500pF is probably best.
     

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