Replace Blend Pot with VVT

Discussion in 'Pickups & Electronics [BG]' started by allboutbass, May 10, 2021.

  1. allboutbass


    Oct 2, 2019

    I have this American Elite Precision that I use mostly in passive mode ,it is a blend and volume pot and I am going to remove the preamp and let it just passive. The P pickup is a PV63 and the J is the stock 4 gen noiseless.

    These are the stock pot values fender told me:

    Volume : 25kA
    Passive Tone: 100K, .1uf cap
    Blend : 250K

    Since I really like the passive tone now, and I am going for V-V-T configuration, I would like to know what pots would get me close to those values. I have no idea how a volume and blend pots total load is

    Also, since I have a custom made pickguard already there I was thinking in filling the extra holes left with going VVT, I might put a series parallel switch and a switch for 2 caps with the 0.1uf and .047uf. So I will have a "more modern" tone cut with the .1uf and a more classic cut with the .047uf ... if this make any sense.

    I am in doubt if going with 250K on all three pots, or may be 250 on vol pot and 500k on tone pot. I have recently changed a AVRI 75 jazz bass tone pot with a 500k and .047uf cap which suits me better than the original 250K/.022uf

    Any thoughts would be of great help
  2. SteveCS


    Nov 19, 2014
    Hampshire, UK
    I would recommend, based on my own experience, 500k linear for your volumes and 250k audio for your tone. For my taste a 0.1uF cap is far to big - rolled back it just creates a flubby mess. But the result does depend a lot on the impedance of the pickup, so it might work for you.

    EDIT: I wouldn't go with a 500k tone pot. All that happens is the control does nothing until you get to the last 1/4 turn - it becomes a switch.

    The cap switch is a good idea, but did you know you can actually get 3 settings from 2 caps if you use a DPDT On-On-On 'pickup selector' type switch? The three settings are 'one', 'the other' or 'both'. Here's how I did it on my PJ - Ignore the resistor and greasebucket switch and just imagine the bottom of both caps going straight to ground.

    Wiring Diagram.jpg
    The switch works like this:
    5StringPocket and allboutbass like this.
  3. allboutbass


    Oct 2, 2019
    Hey thanks for the 3 position switch idea, I think I might actually go for it.
    SteveCS likes this.
  4. bigtone23


    Dec 10, 2014
    Denver, CO
    There is always room for experiments, but here are a couple suggestions for a passive P/J that have done me well in my experiences...
    -For maximum flexibility with the P/J, have some sort of series/parallel switch just for the P pickup (I usually use a push/pull tone control for this so I don't have to push/pull volume controls that may or may not be set to a specific spot). This way you can cop a more convincing J type tone with the P pickup in parallel and blended with the bridge pickup.
    -If going VVT, linear taper volumes give a wider range of finer adjustment. The value you choose will be based on what you prefer. 250K is the traditional value on Fender basses, 500K will give a little more bite to the tone, which can be rolled back with the tone control or amp setting. I posit that Fender used audio taper 250K pots everywhere to keep the amount of part numbers in stock to a minimum.
    -Regardless of the volume pot values, I always up my Fender tone controls to a 500K audio taper. It adds a small touch of air, and it's easily rolled back to around 7 or so to sound just like a 250K pot on 10.
    -The 3 way selectable tone cap switch is also a cool idea for getting a lot of tones. Just know that you don't really hear the cap differences until you are pretty deep into the control--like around 4 or lower on it's setting, and the differences are very noticeable from 0-2. The suggestion of a .022uF and .047uF is solid.
    SteveCS likes this.
  5. allboutbass


    Oct 2, 2019
    Yes, I recently did up a Jazz Bass to a 500K tone pot and I think is much better as the open knob has this "air" as you say.
    On the series/parallel switch thing, I was thinking for both pickups but now you gave me that idea for the P pickup only, do you have any clip or link for it? ... I have never heard a P pickup in series, this got me really curious.

    For me the .022 is actually a bit too honky as the resonance bump is higher but I guess the .047+.022 option is a good idea as I was just thinking only .047 and .1 so I guess having .069/.047/.022 is good enough and sure can make use of the 22 honkyness as it sure has its place.
  6. SteveCS


    Nov 19, 2014
    Hampshire, UK
    You could always go 0.033uF and 0.047uF, for a combined value of 0.080uF...
  7. allboutbass


    Oct 2, 2019
    Yes, that is even better!
    SteveCS likes this.