J-Bass Blend + Series/Parallel switch

[Gmulley]

I'm currently in the midst of rewiring my J-bass (Currently V/Blend/T) to add a series/parallel switch. I came across the attached schematic on a thread from a few years ago, and thought it looked good, however I'm still a rookie when it comes to wiring. Thoughts/opinions from the more electronically experienced? Also, I'd love to hear any more standard J-bass mods!

 

[Tommorichards]

I found this to be pretty awesome, but did it on a bass with a p, soapbar comfig.

 

[SurferJoe46]

I actually like this one better, although they are all 'right' this is easier to see:::

 

[PacAWallop]

Of the 3 Schemes posted this one is the only one that allows you to keep the Blend pot and it's functionality.

The other two require you to go back to V/V/T.

 

[SurferJoe46]

Do I see another switching device in there?

 

[PacAWallop]

Do I see another switching device in there?

[Invalid or Expired Link Removed]

The switch is here, it is a three pole dual throw switch:

Parallel selected:

Series Selected:

 

[line6man]

I drew the diagram in the OP's post a while back.
It actually works better if you swap the first and second terminals of the volume pot, so that the wiper terminal varies the resistance at the output, so the pickups will see a constant resistive load.

SurferJoe, when you go into series mode with a traditional series/parallel switch, the pickups go in series, feeding only the neck pickup's output. When you have two volume pots, the neck pickup's volume becomes a master, while the bridge pickup's volume does nothing. The problem is, when you have a blend pot, you end up only feeding one side, so if you have the blend set toward the bridge pickup, it will attenuate the output in series mode. That's why the diagram has a 3 pole switch. The third pole is used to bypass the blend pot in series mode.

 

[PacAWallop]

I drew the diagram in the OP's post a while back.
It actually works better if you swap the first and second terminals of the volume pot, so that the wiper terminal varies the resistance at the output, so the pickups will see a constant resistive load.

SurferJoe, when you go into series mode with a traditional series/parallel switch, the pickups go in series, feeding only the neck pickup's output. When you have two volume pots, the neck pickup's volume becomes a master, while the bridge pickup's volume does nothing. The problem is, when you have a blend pot, you end up only feeding one side, so if you have the blend set toward the bridge pickup, it will attenuate the output in series mode. That's why the diagram has a 3 pole switch. The third pole is used to bypass the blend pot in series mode.

I like it, Thanks!

 

[SurferJoe46]

So you say that besides the P/S switch I have to also install another switch too?

 

[PacAWallop]

So you say that besides the P/S switch I have to also install another switch too?

No, only one switch. To maintain (volume-balance/blend-tone) function you have to use a 3 pole switch. If you use (volume-volume-tone) then a 2 pole switch is what you want.

 

[deepestend]

Any way to do this with a push/pull rather than a switch?

 

[line6man]

Any way to do this with a push/pull rather than a switch?

If you can find a 3PDT push/pull, sure.
That's a difficult task, however.

 

[DrVenkman]

Well, you can do it with a standard DPDT push-pull, but you do have to compromise. As posted by line6man, the blend pot ends up working kind of like an additional volume.

I decided that's something I can live with and wired my jazz up like that anyway. When I go to series mode, if I've used the blend pot to cut the neck pickup output at all, it will now cut the overall output. In practice I don't switch between series and parallel mid-song anyway, so it's not a big deal for me to just center the blend pot before I switch to series. YMMV.

I don't know if there are any other implications to doing the wiring like that or not. Based on some other threads I read around the time I was making this change I also chose to not ground my blend pot, and I don't know if that makes a difference.

My best advice: listen to everything line6man says!

 

[deepestend]

The more I read, the more I think I may just do VVT with a push pull. I'd really rather have a blend with some kind of switch or a push/pull, but it sounds like too much trouble. The whole point in moving to a jazz was to go passive and simplify my equipment

 

[deepestend]

Okay, here I am nearly three years later and I'm wiring up my jazz again with a blend. I tried going with just a 2 pole switch, but it's not really working out. I'm going to try the three pole switch using the diagram above this weekend.

 

[MothBox]

I did this last year using a blend pot and the series parallel switch, i think in part from advice in this thread.

I remember editing the diagram slightly (vol pot?) As per line6mans advice.

Works a treat.

 

[deepestend]

Thank you! Travel plans are delayed so I'll give this a shot tonight.

 

[deepestend]

Btw, using this with an aguilar opb 3.

 

[deepestend]

I'm having some trouble with this... I've been trying to bridge this and the obp3 wiring scheme and either I can get it all to work in passive or a/p with no s/p.

 

[deepestend]

I'm still having trouble pulling this off, so I emailed Best bass gear and they sent me this diagram. Is there any reason that it shouldn't work? It's jus ta dpdt switch and not a three pole: