Adding a master volume to a 335 style guitar

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by coderKen, May 20, 2015.

  1. coderKen

    coderKen Supporting Member

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    I'm wanting to add a master volume to my epi dot (on the treble-side cutout). If I wanted to keep the traditional controls (neck vol & tone + bridge vol & tone) but just add a master volume, would I just need to wire the MV between the 3-way switch and the output jack? Would it be necessary to use a different pot values or would the regular 500k pots do the trick?
     
  2. walterw

    walterw Gold Supporting Member

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    if you're gonna do all that, you'd be better off modding it so that one of the 4 controls you already have is a master volume. volumes on top of other volumes all tend to load down the tone a little.

    i did just this with my les paul, making the closest knob the volume, keeping the tone for each pickup (sort of like a strat), then just for laughs throwing a rotary switch in the unused 4th spot as a phase-reverse.
     
  3. sfguitarworks

    sfguitarworks Member

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    Walter's solution is certainly an interesting and effective one, but if you did just want to add the master, then yes, you would put it between the switch and the jack. A 500k should be fine as the circuit already has 500k resistors in it. Shouldn't load it too much, but you can use a 1meg if you are concerned.
     
  4. coderKen

    coderKen Supporting Member

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    I had initially though about changing to a neck vol - bridge vol - master tone - master vol set up but I'd really like to keep all of the individual p/u control and just add the master. Thanks for the input!
     
  5. swiveltung

    swiveltung Member

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    I've tried it a couple times over the years. It seems to makes things dead sounding for some reason if you add it in addition to the stock controls.
     
  6. Dana Olsen

    Dana Olsen Gold Supporting Member

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    I've found the same.

    I think there are 4 pots there already, and the output always sees at least two of them. Adding more pots makes the tone flatter and less 3D IMO. I like Walter's solution because it removes or repurposes the existing pots and doesn't add any load to the (already somewhat loaded) circuit.

    Two cents worth, thanks, Dana O.
     
  7. walterw

    walterw Gold Supporting Member

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    You could avoid the tone-suck by making all three volumes 1MΩ instead of 500k, but then you pay a price in how well they sweep from off to full.
     
  8. coderKen

    coderKen Supporting Member

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    So, *IF* I decided to try all three volumes @ 1MΩ, would I keep the tone pots @ 500k then? Also, would it be necessary to use smaller valued caps for the tone pots?
     
  9. twostring

    twostring Member

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    Maybe the setup I use for my dual hum/4 knob guitars would work for you. I'm not a fan of dual volume controls, so I found a 4p3t switch that allowed me to incorporate a blend control into my setup. So my control scheme is master volume, blend pot, and a tone control for each pickup. My switching is neck/blend/bridge. Let me know if you're interested and I'll post the link to the switch and my diagram.
     
  10. walterw

    walterw Gold Supporting Member

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    oh yeah, i've seen this concept before, kinda tricky to wire up but very cool! the blend pot is bypassed when you switch to neck or bridge, so you can use the blend pot to adjust a certain balance between the two pickups and it only engages with the switch in the middle.

    a simpler idea might be to bypass the switch entirely and make the wiring master vol, blend, and two tones.
     
  11. twostring

    twostring Member

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    Yup. I have an esquire with an extra pickup in the middle position that's close to that. Volume, tone, and blend...no switch at all.
     
  12. rhaas

    rhaas Member

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    This wiring scheme with a single master volume sounds really appealing to me. I'm guessing that the guitar's tone is unchanged (relative to stock wiring) in the neck (up) and bridge (down) switch positions but is there any change to the middle position? With the master volume all the way up, I think the pickups would see the same load that they previously did when the individual neck and bridge pots were on 10. Just double-checking my understanding of the circuit.
     
  13. walterw

    walterw Gold Supporting Member

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    you are correct, the individual pickups still get one volume and one tone, and so sound the same; in the middle you have one less volume in the mix taking its toll, and so it sounds brighter and clearer! it also lets me get nice jangly clean tones by turning that one volume down a little, something that's a bit of a bitch to do quickly with two volumes.

    truth be told, i did some more modding to increase my middle setting clarity, by customizing my 3-way switch so that in the middle it disconnected both tone knobs! with nothing but the one volume on it, my middle setting is all kinds of clear and useful. (plus it lets me go from sparkly clear middle right to total tone-rolled-off woman tone neck with just the pickup switch.)
     
  14. rhaas

    rhaas Member

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    That tone pot lift mod sounds interesting and I might have to try that at some point. I definitely want to give the master volume a shot, though! I dig the middle position tones but I find myself using that position less often than I'd like because I'm a big volume knob user and like you said, trying to keep both neck and bridge knobs in sync is really a pain (and it's easy to accidentally reach for the wrong knob when I'm paying more attention to my playing than the pickup selection).

    The only thing I think I'd lose is the ability to make the pickup switch a "kill switch" by turning one pickup completely down. I could probably use a rotary switch in the spare knob position to take care of that (don't really need the phase switching).
     
  15. moredirt

    moredirt Member

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    This sounds promising, would love to see a diagram if anyone's got one.

    Great thread, subscribed, I've been thinking about similar concepts for my Epi Riviera.
     
  16. twostring

    twostring Member

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    walterw likes this.
  17. moredirt

    moredirt Member

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    Yikes. I've further sidetracked the thread and hurt my brain at the same time. My apologies to OP for leading this astray, but thanks to twostring and others for chiming in with MV-related schemes, I'm going to try one when I get some free time, maybe walterw's simplified suggestion of bypassing switch and going MV, blend, tone, tone.
     
  18. coderKen

    coderKen Supporting Member

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    Not sidetracked at all. It's got me thinking about all the different options now. I'm still a ways out on this project so, the more info I can gather now, the easier it'll be when I eventually get to it.
     

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