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A Possible Addition?

Discussion in 'Pickups & Electronics [BG]' started by Bass_Machine, Dec 16, 2005.

  1. Bass_Machine


    Oct 29, 2004
    I was wondering if it would be possible to pay a local luthier to install a switch that bypasses the active circuit in a bass, to make it passive? This would be really useful in case of batteries running out at a gig.
    If posssible, how much would it cost (an estimate) to pay someone to do this?
  2. hmm_odd

    hmm_odd Guest

    Dec 14, 2005
    It can be done pretty easily with most active ciruits, not gonna be too expensive i dont think, im planning on doing it myself with my banger bass when it gets an active pre put in

    Remember it will only be useful if your using passive pickups :)
  3. Bass_Machine


    Oct 29, 2004
    Can you elaborate on this?
    Is there anything else I might need to know?
  4. Normally when people say "an active bass", they mean a bass with a pre-amp in it that is powered by batteries. The pickups are passive; they aren't using batteries to work. Pickups which do use batteries (some EMG's come to mind..) will only work if you do use batteries for them.

    A lot of active basses only have a pre-amp. I'm also planning to do this when I get the Yamaha BB614 next year ;)

    I still have to find a luthier who can do it though. I want the normal active circuit and a passive volume, volume, tone, tone circuit. So volume and tone for each pickup.. If we're installing extra knobs; why not installing double knobs (the stacked ones) and have double the fun with them :smug:

    EDIT: it will both be usefull when you use a active pre-amp or active pickups. But don't do it if you're only doing it to be safe.. I don't think that's worth the money, just check your batteries before every gig and don't leave your cord in the bass when you're not playing. If you're doing it to have more tonal variation; that's OK in my oppinion.
  5. Bass_Machine


    Oct 29, 2004
    Awesome, I have a yamaha BB604, and that's the bass I was planning to get modded, but I also have a fretless that's active and if the mods works for the yamaha, I might get the same additions to it.
    Mostly it's for tonal variations, but It's also really useful in case I run out at a gig and will save on battery costs.
  6. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    There's a little more to it than simply bypassing the preamp. It really depends on the design of the active circuit, the values of the potentiometers used, the location of the tone controls in the circuit, etc.

    It can be as simple as the installation of a dpdt on-on switch to bypass the preamp. It can also be a complicated as redesigning the complete circuit and replacing several of the parts or deciding that you can live without tone controls in passive mode.

    Plus, if you are talking about a factory active system, they often are built on a single integrated circuit board. You just have to have someone who knows what they are doing crack it open and have a look at it.
  7. luknfur


    Jan 14, 2004

    Pretty simple requiring only a switch and you could probably use a pushpull volume/switch pot and skip punching a hole. The switch could be had for around $5 and pot for about $10. The pots aren't limited in terms of resistance. Something you could do yourself with common sense and experience with basic tools. Any tech could do it and give you a quote though. About $20 labor would be my guess.

    Bart and Aguilar both have by-pass switch diagrams for their premaps and I'm sure they're plenty others from a net search. Probably a TB search for that matter and it may even be diagramed in FAQ. Like a railroad switch, you're just redirecting the flow.

    Usually you'll only have volume/blend in passive mode but you could set it up with tone if you want to add/change controls. Pups obviously must be passive to do it to begin with.

    But the probably of a battery going out mid-gig if you have a clue about their lifespan is basically 0. Most will last months to a year. If they don't there may be a couple of wires crossed at the jack. There are some for whatever reason that don't last but a few weeks.