Getting rid of Bass and terrible knobs?

Discussion in 'Pickups & Electronics [BG]' started by Veldar, Dec 31, 2012.


  1. Veldar

    Veldar

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    Hello all I've ordering some SGD pickups and will have to wire them in but I wanted to get rid of my bass and terrible knobs.

    [​IMG]

    So can you guys tell me how to disconnect the bass and terrible knobs, I'm terrible with wiring and need a step by step guide.

    Cheers, Sam.
     
  2. phangtonpower

    phangtonpower

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    Can't really help out, but those are sure indeed terrible knobs ;)
    Happy New Year and hope you get everything sorted out.
     
  3. LiamPodmore

    LiamPodmore

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    I'd be inclined to find a Jazz bass wiring diagram and follow that, thus removing all the active circuitry which you don't want.

    Liam
     
  4. Veldar

    Veldar

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    My dam speeling again.

    I was going to leave the battery in there so I get a higher output sound, Should I take the battery out?
     
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  6. johnson79

    johnson79

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    Did you talk to SGD? Maybe he can help you out with a diagram.

    And thanks for the laugh. At first I thought you hated your knobs.
     
  7. khutch

    khutch Praise Harp Supporting Member

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    Since it sounds like you want to keep the preamp I would just leave the knobs in the flat position. Do the knobs really offend you? If so take a look at the back of the pots, they should be marked with a resistance value. On a preamp they are most likely to be 25k, 50k, or 100k but anything is possible. Whatever the value is (and the two pots could have different values I suppose) divide it by half and get two standard resistors that are close to that value for each pot. For the example pot values above you would use 12k, 22k or 24k, and 47k. Now unsolder the pots and solder the resistors in their place, with one resistor soldered to each spot where the pots outer lugs were and both soldered to the spot where the center pot lug was. You now have fixed the preamp bass and treble settings to flat.

    If you like some other setting than flat you would first fiddle with both knobs to get the tone you want. Then unsolder the pots. Then measure the resistance value from center to either side with the pots set as you like them. Then replace the pots with resistors having those values, as close as you can get.

    You are on your own when it comes to filling the ugly holes left by the missing pots....
    Ken
     
  8. wcriley

    wcriley

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    What makes you think the battery will boost the output after you've removed the Bass and Treble boosts?
     
  9. JimmyM

    JimmyM Supporting Member

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    And what will you do if you want to adjust the tone?
     
  10. SGD Lutherie

    SGD Lutherie Banned

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    I would just leave the preamp, unless you really don't like it. But I've used EMG preamps and they sound very natural. When you have it set flat it sounds the same as bypassed.

    I used a BTC preamp for years with my pickups, and I liked it. I usually always had a little bass boost dialed in, and then would change the treble to get the tone I wanted for what ever I was playing. Sometimes I want a bright tone. Sometimes I want a darker tone, etc. I think the preamp is very handy to have.

    The first two sound clips on my website were played through an EMG BTC preamp.

    Otherwise remove it and the bass and treble pots and wire up a passive tone control. But then you will have an extra hole.

    To keep the preamp, just wire the new pickups to the blend control.

    Also, preamps don't boost the signal unless you turn up the bass and treble knobs. But you should never turn them both all the way up.
     
  11. line6man

    line6man

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    As khutch said, use four resistors to simulate the load of the pots in the circuit. Two for each pot, each equal to one-half the rated value of the pot. Alternatively, you can use trimmer pots mounted inside of the control cavity.

    Note that having a preamp does not necessarily mean having a high output. That depends entirely on the design of the preamp. Many are unity-gain, and the ones that do offer a gain boost usually have a trimmer pot to adjust it. Personally, I would consider removing the preamp, since the pickups are active, and thus, you already have the advantage of the low impedance buffered output. There is no reason to chain multiple gain stages in series by running active pickups into a preamp. That only decreases headroom and increases noise.
     
  12. SGD Lutherie

    SGD Lutherie Banned

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    The pots are mounted right to the preamp PCB. I think that would be a lot of work for someone not experienced in electronics to remove them.

    I'm not sure that's what he's talking about anyway. If this is who I think it is, he was asking me if his preamp was compatible with my pickups, which it is.

    It's all more bother than it's worth. Either just leave the preamp, or remove it.
     
  13. mmbongo

    mmbongo Chicken Pot Pie. My three favorite things!! Supporting Member

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    This has to be a contender for thread title of the year though!
     
  14. Primakurtz

    Primakurtz Registered Nihilist Supporting Member

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    All my basses seem to have boost-only terrible knobs, dammit.
     
  15. mmbongo

    mmbongo Chicken Pot Pie. My three favorite things!! Supporting Member

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