Weird idea: will this work?

Sandu · #1 03-27-2008, 02:35 PM

Due to some misunderstandings, I won't be having soapbars on my soon to be 8 strings (single course), so I decided to take a walk on the wild side.

For maximum versatility, I and the builder decided to go with a 4 J-type pickups paired, acting as 2 large P pickups. Here's where it gets messy: i thought of having a series/parallel switch for each pair, a series/parallel between pairs and a 2 band preamp with a blend pot, so that's 3 switches and 4 knobs. I wanted to do the schematics and electronics, he'll build with what I'll give him.

So far I came up with this schematic for one of the pseudo-P pickups with the switch:

I derived it from the following one, standard jazz wiring with s/p switch:

I'd like to know if what I made here is correct. I left out the whole preamp part out, since it's all stock there, no problems. I'd also like to know if placing that 3rd switch between assemblies is even possible

. It looks right to me, I just copied what I saw in the standard schematic...

mjolnir · #2 03-27-2008, 02:38 PM

That just makes my head hurt... Looks kinda like it'd work though.

Sandu · #3 03-27-2008, 02:45 PM

I forgot to ask... are those "mid-air solder points" between wires (the dots on intersecting wires) bad? Because I haven't seen too many schematics with those, if any.

mjolnir · #4 03-27-2008, 02:48 PM

Quote:

Originally Posted by Sandu

I forgot to ask... are those "mid-air solder points" between wires (the dots on intersecting wires) bad? Because I haven't seen too many schematics with those, if any.

It would work just fine to move those points to the actual switch itself.

Sandu · #5 03-27-2008, 02:59 PM

Wow, I was so proud just a minute ago, having finished the schematic, but never thought of moving those solder points to the switches

kinda embarrasing... Too little live soldering action, too much forum browsing, I guess...

mjolnir · #6 03-27-2008, 03:02 PM

Quote:

Originally Posted by Sandu

Wow, I was so proud just a minute ago, having finished the schematic, but never thought of moving those solder points to the switches

kinda embarrasing... Too little live soldering action, too much forum browsing, I guess...

We all have our moments.

David1234 · #7 03-27-2008, 03:15 PM

Hi! What benefit are you expecting to get from having two neck pickups, which are on different strings, wired in series? It's not going to make a note louder or fuller and will give one pickup a floating earth which would worry me for noise.

I would humbly suggest not drilling the holes for those extra 2 switches in your nice new bass til you've heard the settings and seen if they're worth it? (like wire it up "outboard" and check whether it does anything before committing).

mjolnir · #8 03-27-2008, 03:16 PM

...He has a point.

Kennethfaria · #9 03-27-2008, 03:25 PM

Hey would there be anything wrong wiht having 3 Jazz bridge pickups? I've seen wicks with 2, just wondering.

Sandu · #10 03-27-2008, 03:52 PM

Quote:

Originally Posted by David1234

Hi! What benefit are you expecting to get from having two neck pickups, which are on different strings, wired in series? It's not going to make a note louder or fuller and will give one pickup a floating earth which would worry me for noise.

I would humbly suggest not drilling the holes for those extra 2 switches in your nice new bass til you've heard the settings and seen if they're worth it? (like wire it up "outboard" and check whether it does anything before committing).

You mean that the neck pickups, not being wound reverse between themselves, will not have the same effect as an actual bridge+neck set? And I guess using a set as one of the P's won't work either, because of the difference in volume...

Hmm... thinking time...

As for the sound, I'll surely test the thing before drilling any holes, the bass is only just beginning to take shape anyway.

David1234 · #11 03-27-2008, 03:55 PM

I assume you mean three J's on a 4- or 5-string bass rather than the kind of thing this thread is talking about?

I used to own a Maton JB4 with three J pickups. Two in the typical fender positions and one exactly in between them. It had a volume control on each pickup and there were an amazing variety of tones available by dialling odd combinations like neck pup 75% on, middle 25% on, rear 100%. I think it's a great idea, but I should mention that on stage it's certainly easier and much quicker to change from one good tone to the next by using two similarly-voiced pickups and a blend pot.

There's a traben bootsy model with 5 J's (good grief!)...

I guess you could pretty easily make a bass that's "too versatile"...

David1234 · #12 03-27-2008, 04:09 PM

Quote:

Originally Posted by Sandu

You mean that the neck pickups, not being wound reverse between themselves, will not have the same effect as an actual bridge+neck set?

Yes. Do you need hum cancelling anyway? (What pickups are you planning?). If you do, your choice is to either do it within each pickup group (the neck group, or the bridge group) or do it by switching all the pickups on, and the series/parallel doesn't really have anything to do with that choice.

My personal taste is not to muck about with series switching, this allow me to take advantage of a blend pot but that might not be for you. But I'm not willing to "advise" you to abandon your idea without testing it cause you might have invented something really cool!! My only friendly advice is don't put "flavour of the month" holes in an "i want to keep this forever" bass!!

Sandu · #13 03-27-2008, 04:10 PM

Well is the volume radically different between pickups? Can't I use a set in one of the pickup groups?

I don't mind having a couple of extra switches on the bass, as long as they do something... My initial idea was to have a couple of MM style pickups with a single/series/parallel switch on each, I gave up because the lack of funds, the soapbars were to be placeholders until i had funds for the MM's, so I thought I could do a mockup of the MM setup I initially wanted using 2 single coils as a P pickup, with series/parallel switch on each. Actually, I'm dead-set on having the option, so one way or another it has to be done.

Kennethfaria · #14 03-27-2008, 04:11 PM

haha yeha i was planning on using it by the bridge. looks like itll work thanks!

Sandu · #15 03-27-2008, 04:42 PM

David1234 mentioned something about a floating earth on one of the pickups... I guess it happens on a certain combination of positions of the 2 switches between the blend pot and that pickup... Can someone shed some light on that?

David1234 · #16 03-27-2008, 05:34 PM

When in series mode the top pickup in each group (labelled "bass pickup") is being connected to the hot wire of the other pickup instead of being connected to the ground.

I should be more clear, it's not entirely "floating" but it isn't grounded either!

GeoffByrne · #17 03-28-2008, 04:25 AM

Have you looked at a Fender Roscoe Beck?

http://en.wikipedia.org/wiki/Fender_Roscoe_Beck_Bass

http://www.fender.com/products/searc...tno=0196402842

http://www.fender.com/support/diagra...400_02APg2.pdf

Sandu · #18 03-28-2008, 05:59 AM

Nearly there with the full schematic... What's missing now are the preamp and the Bass and Treble pots, but I don't need those in the schematic, they're already soldered together.

Well is this one correct?

At least I know the first half, up until the 3rd Series/parallel switch, is ok. What about the active/passive and killswitch?

I took the passive/active with the passive tone pot part from another schematic, but for some reason it doesn't look right to me...

Sandu · #19 03-30-2008, 03:13 AM

Another Q: What happens if you wire a series/parallel switch on a 2 humbucker configuration? Will the sound differ in one position or the other, or will it do nothing?