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Anybody clip the bright cap in your AC15C1? (Bright cap mod)

Discussion in 'Amp Tech Center' started by DannyStereo, Oct 31, 2015.

  1. DannyStereo

    DannyStereo Poster Extraordinaire

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    I can't shake the fizziness when I step on an overdrive. If I start cutting tone on the pedal/guitar/amp, it gets wooly. Anyone try the bright cap mod with good results?
     
  2. RoscoeElegante

    RoscoeElegante Friend of Leo's

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    I've got one, stock, and ran into the same thing. It's a touchy amp, I think, with, for me, a hard-to-find sweet spot.

    What helps mine gets some girth and depth is using my Prince of Tone with its tone knob pretty low, down at around 9 o'clock, its drive around 10, and on the Boost setting, which I think is the real key. (It fizzes, farts, and muds out on the OD and/or Dist., too.)

    On the amp itself, using the POT, if I go through the Normal channel, I have the tone cut at around 3 o'clock. If I go through the Top Boost, I have the bass at 4 o'clock, the treble at 9:30, and the Volume maxed out, riding the Master at around 2 o'clock. This thickens it up pretty nicely.

    Took me about three weeks to figure this out.

    I find that it takes bridge humbuckers best, followed by P-90's and stronger-than-vintage single-coils. It's less and less usably thin the more you go toward vintage-output s.c.'s.

    But that thinness, down to a point, can work really well when run in stereo with a throaty/honky amp. So I pair the AC with my Excelsior Pro almost all the time. It really adds a great shimmer to that amp when the Exy is set toward the dark and deep end of things.

    On its own, I play it with the darkest pickups I have (Epi and Reverend P-90's). It really works well, then. I find it easier to find the non-fizz depths by starting as dark as possible and working toward the bright side. When I get a hint of fizz, I back off dark-wards and find that good alleyway.

    I hope this helps in some way. Please post back about your experiences as you try people's advice. I'm sure that I've found only some of what's great in the AC15, and am eager to try out different approaches, myself.
     
  3. DannyStereo

    DannyStereo Poster Extraordinaire

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    Well, I play a Reverse plate Butterscotch with OV pickups and a Classic Series 50s Esquire... So yeah the vintage output is there.

    I did the mod on the Top Boost Channel, and it didn't make a whole lotta difference...
     
  4. RoscoeElegante

    RoscoeElegante Friend of Leo's

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  5. DannyStereo

    DannyStereo Poster Extraordinaire

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  6. DannyStereo

    DannyStereo Poster Extraordinaire

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    Otherwise, it just may not be the amp for me anymore
     
  7. Chriss945

    Chriss945 Tele-Holic

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    The bright cap mod on the top boost channel is incredible. Don't do it to the normal channel though! As soon as I did it, the pedals sounded smoother and less fizzy. It doesn't solve all the problems with Vox amps. Most Vox amps can only successfully work with a very select few OD pedals, and others do not work at all - TubeScreamer for example is a no go. Do it, you might like it :).
     
  8. FenderBender10

    FenderBender10 Tele-Holic

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    I think I may have gotten lucky with my AC15c2 because it sounds phenomenal with every pedal I throw at it, especially a tubescreamer. Maybe because of the 2x12 and bigger cab?? No mods, completely stock. I thought of doing it when I first got it but I really learned its controls and I didn't want to change something that already sounded great.
     
  9. bparnell57

    bparnell57 Poster Extraordinaire

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    A Soul Food can work really well with an AC30. Keep the tone knob below 12:00 on the pedal and don't be afraid to turn up the cut control on the amp.
     
  10. Halo

    Halo Tele-Meister

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    I removed the bright cap on an AC15 of a friend of mine. I'm not sure which particular model, but it was located on the PCB holding the potmeters.
    It took away some of the shrillness at lower settings, very recommended mod.

    Next thing to do on this amp is to install a tone cut. This particular amp has it hardwired in the PCB, so it is always at the maximum setting.
     
  11. JD0x0

    JD0x0 Poster Extraordinaire

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    What preamp tubes? I have had issues with certain 12AX7's sounding 'Fizzy' when overdriven. I generally like the New Production Tung Sols and Mullards, because they seem to lack the fizz compared to some of the Chinese 12AX7's and JJ's I've tried. I do like the JJ ECC803S, though.

    Amp drive always sounds better, to me, with a healthy tube amp, well setup. Using OD/Distortion pedals to 'fix' a tube amp's overdrive seems rather counter productive, to me. It should be able to overdrive on its own without nasty fizz, IMO.
     
    Veeseaczar likes this.
  12. bparnell57

    bparnell57 Poster Extraordinaire

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    If you want classic searing AC15 "Kinks" style tone, just go ahead and get some nice test equipment pulled mullards. They're often tested for low noise and high gain, and since they're not NOS they haven't been cherry picked and don't carry a huge price tag.

    If you want some warmth, look into old GE's, Tung Sol's, or one of the JJ variants.

    These are all subtle differences mind you, but they do make a difference.

    JJ's are great for taming ice pick in my experience.
     
  13. DannyStereo

    DannyStereo Poster Extraordinaire

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    It has JJs all around, Pre and power.

    They are a little on the older side, but I'm thinking I may just be ready to go back to the 'Fender' or 'American' type amps. I much prefer my 6L6 amps these days.

    And I'm just not a fan of the 'cranked tube amp approach'. Makes all my delays sound mushy
     
  14. Ash Telecaster

    Ash Telecaster Friend of Leo's

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    I must be one of the lucky ones because mine sounds just killer. I did find one adjustment that made a world of difference to me. I generally don't play with tone knobs much as they just don't seem to do much. At least much that actually improves the tone. My 5e3 would be an exception to that but usually if I'm having a tone issue the tone knob generally isn't the solution. In the case of the ac15c1 I have found the tweaking of the tone knobs to be essential to nailing the tone. And the treble and bass interact with each other in a strange and unexpected way. For me, I point them at about Bass 2, Treble 11.

    I find the character of the amp changes dramatically as it warms up. The amp is totally blah when I first turn it on. After about fifteen minutes of playing it gets all gritty in a good way.

    I don't use a lot of dirt from the amp. Just get it to the edge and then use my OCD. I find the amps distortion can be a bit muddy by itself.

    There might be something else going on too. I have heard many people describe their ac15c1 as bright but that doesn't fit mine at all. In fact it is much warmer sounding than my Twin or my Blues Jr. Maybe there have been component changes over time and I got lucky and bought one of the warm ones.
     
  15. DannyStereo

    DannyStereo Poster Extraordinaire

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    I think maybe it's my ODs that don't work so well with it:

    Jetter jet drive
    Plimsoul
    Butah
    Fatboost
     
  16. crossroader

    crossroader Tele-Afflicted

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    I recently pickup up an AC15HW.
    All I've done with mine, so far, is loaded it with Tung Sol RI tubes (pre and power - with a EH rectifier). I'm not quite sure how different the HW circuit is from the C1 (other than being hand-wired vs. PC-board, of course), but I have no plans to be modding anything anytime soon.

    To be honest, I'm still learning how to set it up. I'm a Fender amp guy from way back and the Vox is a completely different animal when it comes to working the controls.
    I've played a few different Telecasters through mine and while I can see how things might get a little "fizzy" on the top end, I'm learning that the Cut knob is an essential piece to this tonal puzzle. And it can be a little touchy, but once I get it dialed in, I really like what I hear. And that setting will vary with each guitar I plug in.

    One thing that surprised me about my AC15 is the bass - it's got a BIG low-end to it. Combine that with that top-end "chime" (see below) and it's a really big sounding 15 watts.

    As far as pedals, hitting it with my MXR/Dunlop MC-401 Boost/Line Driver does wonderful things, bringing out that classic Vox distortion - nice and smooth with that edgy bite that keeps notes well-defined. I never quite understood that whole "Vox chime" thing as a description, very well.....I think I do, now.

    I also like the results I've gotten with a couple of Digitech Hardwire pedals - the SC-2 Valve Distortion and the CM-2 Tube Overdrive. I've used both of those with great success while running the amp at clean levels (i.e., NOT on the verge of natural overdrive - running the Master volume full up for maximum headroom).

    I've also gotten some very nice, saturated distortion with a TurboRat - but the T-Rat settings were quite a bit different than what I typically set up with my Deluxe Reverb. I had crank up the level and adjust the tone knob to fit the tone of the Vox.

    So, while the controls may not be as straight-forward as my old Fender amps, I'm really enjoying the learning process with this Vox - and liking (most of) the results I've been getting.
    This one's definitely a keeper, for me - good luck with yours, Danny!
     
  17. bullfrogblues

    bullfrogblues Friend of Leo's

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    I've not done the bright cap mod on my AC15, but I don't seem to notice any unwanted tones or brightness when I use it. I've dialed in both the top boost and the normal channels with respectable tones for me.
    My favorite pedal to hit the AC is a Quinn Hot Buttered Scotch, and boost that with a Timmy with almost no gain.
     
  18. DannyStereo

    DannyStereo Poster Extraordinaire

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    I'm finding that lower gain settings on pedals sound better, but I'm still in the 'selling it' camp for now.

    Just feeling the American tones more these days.
     
  19. Ash Telecaster

    Ash Telecaster Friend of Leo's

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    I have to correct my statement. The tone knob gets set at 2 o'clock and 11 o'clock respectively. That is an important distinction as the amp would sound lousy at 2 and 4.
     
  20. robrob

    robrob Poster Extraordinaire Ad Free Member

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    Keep in mind that with volume pot mounted bright caps the lower the volume the more high freqs are bypassed around the volume control and at max volume the bright cap does nothing. Tone naturally darkens at low volume because high freqs tend to get filtered out when run through high resistance, like 900k with a 1 meg volume pot set on 2.

    But the AC15 has a low value 70KL volume pot so the bright cap action would be less noticable than with a 1M pot.
     
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