Not covered in FAQ: Series/Parallel for dual stack pots

LeftyPem · #1 08-09-2007, 09:06 PM

Hey all. I'm kinda new here (been lurking about 3 weeks.) I'm currently finishing up a project bass for my brother, and I'v hit a wall. It's a PJ set up with dual stack pots ( original 1962 Jazz style,) but I want to throw a Series switch into the mix. Every diagram I have tried has failed to yield working results. Either one setting on the switch gives me standard parallel output and the other setting is dead, or my knobs both turn off ALL sound while in parallel mode (not supposed to happen.) What am I doing wrong? Please help!! I've put a lot of work in so far (a lot of money too,) and I am completely stumped. This is all kinda new to me, as it's my first bass project. I own one bass right now myself, though its currently all stock, and the previous two I had were also stock. I am mainly a guitarist, but my brother is a big basser. I'll have him on the forum soon. This is only my 3rd electronics job so far, and the first to include all new custom wiring. I will post pics and specs soon. It's really a sweet bass, and I hope it will be a real tone monster.

i_got_a_mohawk · #2 08-10-2007, 02:46 AM

Im not 100% sure what you are finding to be the problem.

One thing that might be throwing you off is:

When your two pickups are in Series, they are acting as one pickup, not two. So only one of your volume controls will work. In parallel they are more independant of each other and hence have two volume controls.

http://www.dimarzio.com/media/diagrams/4Conductor.pdf

has an example of how to wire it up,

I tried finding a better wiring diagram i had, but couldnt find it

i_got_a_mohawk · #3 08-10-2007, 02:54 AM

Here we go:

It basically covers what your wanting, all a dual stack pot is, is two pots ontop of each other, so just copy the wiring for the switch between the volume pots. And then wire up the rest of the bass accordingly.

Again tho, in series mode, one of your tones and one of your volumes will be off.

i_got_a_mohawk · #4 08-10-2007, 03:11 AM

Ok, im bored and have nothing better to do . . .

Ive modified the J-62 wiring diagram off the fender site. I used different colours to make the wiring a bit clearer.

In parallel both pot stacks will work as normal. In series mode, only the bridge stack will be on.

LeftyPem · #5 08-10-2007, 09:18 AM

Awesome. I will give these all a shot. One of the biggest problems I was having was regardless of which "mode" I threw the switch into, both volumes and both tones would control the overall output, not the output from the individual pickups.

You guys are awesome for helping me out, and so fast too! If I get one to work, we should add it to the FAQ. It would be helpful for other dual concentric mods (like the Dano basses.)

LeftyPem · #6 08-10-2007, 10:43 AM

Negativo. Hooking up everything per your edited Fender schem has left me with a very loud buzzing noise when I plug in.

bassmanrocke · #7 08-10-2007, 11:08 AM

Why not run the two sections of your p-pickup series/parallel and leave the bridge pickup out of the switch all together. Since the two sections of the p-bass are reverse wound to be hum-cancelling I think this would actually give you more tonal options and would be far less complicated. I have a p-bass that I wired with a parallel/series switch and it is fairly straight forward and makes a noticeable difference in tone.(Schematics on dimarzio website)

i_got_a_mohawk · #8 08-10-2007, 01:15 PM

Quote:

Originally Posted by LeftyPem

Negativo. Hooking up everything per your edited Fender schem has left me with a very loud buzzing noise when I plug in.

Im not sure where your problem lies, because ive checked that diagram again and again, and that is a series / parallel switch.

(in parallel the pickups are independant of each other, in series the neck coil connects to the bridge (hot connecting to ground) putting the pickups in series with each other).

I also have done this switch on more than one occasion, so, i dont know whats up?

Post some pics of your wiring.

Quote:

Originally Posted by bassmanrocke

Why not run the two sections of your p-pickup series/parallel and leave the bridge pickup out of the switch all together. Since the two sections of the p-bass are reverse wound to be hum-cancelling I think this would actually give you more tonal options and would be far less complicated. I have a p-bass that I wired with a parallel/series switch and it is fairly straight forward and makes a noticeable difference in tone.(Schematics on dimarzio website)

Putting the P pickup between series and parallel does give some tonal difference, but not even close to the difference you get from putting two seperate pickups in series with each other (as opposed to the standard parallel).

LeftyPem · #9 08-10-2007, 09:44 PM

I'll post some pics tomorrow night. My P pickup is not RW/RP. Its vintage spec from GFS.

LeftyPem · #10 08-12-2007, 12:03 PM

Ha! Got it working. I used a modified Gibson layout. It's their standard V/V/T/T setup, with the series /parallel switch stuck in. Man what a headache this was. I'll still throw pics up, but I'm off to get strings for it now, so I will string it up and take the pictures. Thanks for all your help mohawk. My brothers other bass is V/V/T, so if he'll let me, I'll use your diagram to S/P that one. It's a green plaid Ibanez RD707.

LeftyPem · #11 08-12-2007, 04:29 PM

Here's the wiring I went with. My pots, btw, are dual concentric CTS full size built by HAS sound. 250/250. Neck cap is .1 and bridge is .033. Switch is good ol' RadioShack. I just got back from GC where I bought it D'addario Half-Rounds 45-100. Put em on at the store and had a few people there try the bass out. It was set up pretty close to good, and the guys there liked how it looked and sounded. Pics and full spec coming soon.

LeftyPem · #12 08-12-2007, 07:57 PM

I posted finished pics in the Essex forum (the neck is an SX black block.)