Wiring / control layout help?

Discussion in 'Pickups & Electronics [BG]' started by jrcorp, Apr 13, 2012.

  1. jrcorp

    jrcorp Guest

    Jan 22, 2012
    Coventry, Rhode Island
    I'm still working on upgrading my '02 SR300DX, and I've been tackling the electronics a little at a time. I've bought an SPB-1 and I'm on the lookout for a good J to match, and in the meantime I just bought a Blackouts 2-band tone circuit off T-Mac.

    The bass has the stock 4 controls right now - Vol, Vol, Tone, and active Bass boost. I will be replacing the Bass boost, and installing the 2-band tone circuit. The circuit is the 2-knob version, but I notice the PCB looks identical to the 1-knob model so I'm considering converting it to 1 knob as a farfetched option.

    I don't have much experience with bass electronics but have done a lot of work with my guitars and amps. I've never used a stacked or blend knob, but I have used push/pull for coil splitting. I've done some reading about controls and wiring here, and I'm hoping to achieve the most versatile setup I can.

    I like having the Vol/Vol setup and have read different opinions and info on blend setups, but I'm open to trying it. Options I was hoping to try include active/passive and series/parallel switching. A tone knob to work in a passive setup would've been cool but I'm not sure if I could make it work.

    So what do you think? I'm open to drilling holes as I already drilled and doweled for a bridge. What is possible, and what would be more useful or practical? I'm open to push/pulls, DPDT switches, concentric pots, blend... lay it on me. :help:

    P.S. the bass is already active with a 9V compartment so no worries there.
  2. Go with two volumes if you want a master series/parallel switch. A blend would require 3PDT switching.
  3. jrcorp

    jrcorp Guest

    Jan 22, 2012
    Coventry, Rhode Island
    Thanks for the tip. Unless I use a concentric knob for that end, I'm sure I'll have to drill. I need to take a look at the control cavity to see what kind of room I have, as routing is something I won't do.

    Does a series/parallel switch give a big change in tone, especially with a P/J setup? I'm talking about running the P and J together, as the J will probably be a single coil. If I want passive/active as well as series/parallel, I will definitely need to drill and would probably throw in a switch or two instead of push/pull pots.

    I think passive/active takes priority over trying for a series/parallel setup here. Is it possible or helpful for me to use a series/parallel, or to run a passive tone knob in passive operation?

    Finally, I was planning on 500K pots for a little more versatility. But I'm worried I won't be able to get anywhere near the same tone if I were using 250K. Does the taper of the volume affect brightness as well as the tone knob?
  4. A few people here have done series/parallel switching on PJs. I have no comment on the tonality, as I've never tried it. Personally, I wouldn't bother with it, however.

    Pot values don't affect the versatility of a bass. They only make you a touch brighter or warmer.

    The taper of a pot is of no relevance to the behavior of the circuit, it simply affects the way the control adjusts as you turn the knobs. For example, an audio taper reaches the halfway point in its resistance range at around four-fifths of the rotation, while a linear taper reaches the halfway point at one-half the rotation.
  5. jrcorp

    jrcorp Guest

    Jan 22, 2012
    Coventry, Rhode Island
    Thanks for the info and your opinion. I might skip the series/parallel. I used the wrong words asking about pot values, but I'm glad that you explained everything anyway. Now I'm not sure about going 250K or 500K, and I'm also unsure on linear or audio... I have used audio in the past, but maybe I'll give linear a shot. I know walterw always recommends linear.

    Part of me wonders how much these aspects of the setup will affect everything once I dial in a tone with the active preamp anyway, then there's the strings, amp, etc.
  6. Linear is the way to go for volume pots. Stick with audio for the tone pot, however.

    Don't overthink it with values, however. It's really not a big deal, the effect is more subtle.
  7. jrcorp

    jrcorp Guest

    Jan 22, 2012
    Coventry, Rhode Island
    Cool, thanks.

    Any more tips on the series/parallel deal? It would be awesome to hear from someone who's done it with a P/J. I've put off making a Mouser order forever, and it's about time I make a list and get it done.
  8. bassbenj


    Aug 11, 2009
    I wish I could tell you all about it, but while I considered a series/parallel option when modding my Squier P/J, fact is I didn't do it yet. All I can say was the plan I toyed with was to put push/pull type volume controls for the vol/vol setup with one volume push/pull for series/parallel on the split P-bass neck pickup and the other push/pull volume on the P-pickup and J pickup (wired like the Jazz bass mod for series/parallel option).

    But haven't even tried it yet, so I can't say if it's worth the effort or not.