How do I wire up my bass???

ashtray · #1 07-12-2009, 12:03 AM

Putting together a jazz bass, and I have two options: install a used preamp for which I am not certain how to wire up the pickups to it, or just keep the bass passive. For simplicity, let's say I want to go passive.

I have two Hwy1 Jazz pickups. I have regular pots, and a couple push-pull pots at my disposal. I even have a 3 way rotary switch I could salvage from a Squier '51 if I wanted.

The bass has 4 holes for knobs (side mount jack).

I'm open to suggestions! I was thinking of going with:
Master Volume
Blend
Master Tone
Rotary Switch from series to parallel (?)

What would the wiring scheme look like for this?

What other things could I do instead?

**line6man** · #2 07-12-2009, 12:09 AM

How about the standard VVT setup plus a series/parallel push/pull?

It's a pretty useless mod, but maybe a phase switch?

I could draw you the diagram for whatever setup you choose. I don't know what your preamp is though, so tell us what make and model you have.

southernrocker · #3 07-12-2009, 12:11 AM

You coul do my personal favorite:

Vol neck
Vol bridge push pull to engage the rickenbacker capacitor
tone
Series/off/parallel 3-way switch

If you like any of this and wanna know how just pm me.

Jazz bass wise I would DEFINATELY do the rick upgrade. It cost me 8 bucks for the push-pull pot and the capacitor. Here is the rick tone in action, watch the video at 4:55
http://www.youtube.com/watch?v=bjhsH...e=channel_page

ashtray · #4 07-12-2009, 12:59 AM

Quote:

Originally Posted by line6man

How about the standard VVT setup plus a series/parallel push/pull?

It's a pretty useless mod, but maybe a phase switch?

I could draw you the diagram for whatever setup you choose. I don't know what your preamp is though, so tell us what make and model you have.

The preamp is a Blade (Levinson) preamp. They were kind enough to send me a very detailed drawing of how it works - though it's about a masters degree in electrical engineering above my head to figure it out!

cell phone pics to follow...

I'm guessing these are volume and blend (double pot for blend, right?):

Here's the full shot:

The pre-amp has 2 push/push pots - I think for bass and treble. Not sure what the pushing switches though. There's 5 wires that come out of the board:

Black - common ground
Red - Battery (but then there's a black wire coming out of the battery to the sleeve of the output jack)
Green - Center post on volume knob
Black - output jack TIP
Yellow - just hangin' free (yikes!)

The blend knob has the outer posts of each crossed with the opposite outer posts of the second pot. (I guess this is normal for a blend?)

Volume pot has right post grounded to the pot casing. left post has a yellow wire going to the top left post of the blend pot.

**line6man** · #5 07-12-2009, 09:41 AM

Quote:

Originally Posted by ashtray

The preamp is a Blade (Levinson) preamp. They were kind enough to send me a very detailed drawing of how it works - though it's about a masters degree in electrical engineering above my head to figure it out!

cell phone pics to follow...

I'm guessing these are volume and blend (double pot for blend, right?):

Here's the full shot:

The pre-amp has 2 push/push pots - I think for bass and treble. Not sure what the pushing switches though. There's 5 wires that come out of the board:

Black - common ground
Red - Battery (but then there's a black wire coming out of the battery to the sleeve of the output jack)
Green - Center post on volume knob
Black - output jack TIP
Yellow - just hangin' free (yikes!)

The blend knob has the outer posts of each crossed with the opposite outer posts of the second pot. (I guess this is normal for a blend?)

Volume pot has right post grounded to the pot casing. left post has a yellow wire going to the top left post of the blend pot.

All we really need to know about the preamp is which wire goes where, but it's nice to have the full schematic.

Was there a particular setup you had in mind with the preamp?

ashtray · #6 07-12-2009, 10:53 AM

Setup? Well... if I'm using the pre-amp, I'm happy to use it as a volume, blend, and then whatever the preamp controls are (I think they are bass & treble boost/cut). In this case, where would I wire the pickup wires to? And where would the yellow wire from the preamp go to? (if it's not possible to figure this out, then I'm happy enough to go with a passive setup instead)

Thanks!

**line6man** · #7 07-12-2009, 11:07 AM

The pickups will go to the blend pot's center terminals.

Your picture of the volume/blend pots does not match the schematic.

According to the schematic, you should have a 25K volume after the preamp.
Your picture shows the blend pot feeding into a volume pot (250K or 500K) which i am assuming then connects to the preamp.

**line6man** · #8 07-12-2009, 11:12 AM

Also, your blend pot appears to be wired backwards.
If this is a linear taper blend, then you're fine, but if this is a log/anti-log pot then the taper will be running backwards.

ashtray · #9 07-12-2009, 11:53 AM

The blend pot says: M500k, 500k, 29k
The volume pot says: M500k ohm A, 23k

Does that help?

And any idea where the yellow wire from the preamp should go to?

**line6man** · #10 07-12-2009, 12:11 PM

Quote:

Originally Posted by ashtray

The blend pot says: M500k, 500k, 29k
The volume pot says: M500k ohm A, 23k

Does that help?

And any idea where the yellow wire from the preamp should go to?

I would recommend that you get the 25K control after the preamp if you want a true volume control.
If you like the treble roll off associated with passive controls, then stick with the 500K pot before the preamp.

My guess would be that the yellow wire could be a ground.
Why don't you ask the manufacturer for the wire color code?

ashtray · #11 07-15-2009, 02:47 AM

Would it make sense that there's two grounds coming out of the preamp wiring block?

I asked the manufacturer - they said the colors are not consistent and I need to follow the wiring diagram. Just wish I knew how to read it...

**line6man** · #12 07-15-2009, 11:06 AM

Quote:

Originally Posted by ashtray

Would it make sense that there's two grounds coming out of the preamp wiring block?

I asked the manufacturer - they said the colors are not consistent and I need to follow the wiring diagram. Just wish I knew how to read it...

Well, I have no problem reading the schematic, and it's still quite a PITA to figure out whats what on the PCB...

What kind of company changes their color codes without documentation?

What you need to do is see which components the yellow wire is connected to, then you can find them in the schematic.
If you could post some clear pictures, i might be able to help.
This is actually pretty straightforward stuff as far as the schematic and components are concerned. If you take this to an electronics store or something, they should be able to help you trace the yellow wire to components on the PCB that are identifiable on the schematic.

It could be another ground. I don't know why you would want two different colors for wires that go to the same place though. If you had two grounds, they should be the same color.

ashtray · #13 07-15-2009, 01:46 PM

Cool - I'll trace the pcb tonight and see where it goes. Thanks for the help - much appreciated!!

ashtray · #14 07-15-2009, 09:34 PM

Here's more pics. the yellow wire looks like it goes to the 2nd pin in, 2nd pin over. from there on the component side, it looks like it goes to the middle bottom trim pot. (??)

This pic shows it best. You can see where the yellow wire comes in at the right side, middle. That pin you can see then is connected up to the top left - 2nd in, 2nd over. That's connected to a little thing on top. Then if you look at the first picture above, you can see the trace from the that point up and under the control pot and back down to the blue box (trim).

ashtray · #15 07-17-2009, 01:13 AM

*********UPDATE*************

I figured it out! By dumb luck maybe? Or maybe I just ran out of places that the yellow wire could possibly go to...

The mystery yellow wire connects to the THIRD tab of the output jack! I guess this either tells the system the cable is plugged in or not (thus turning on the electronics), or maybe this was part of the output... either way, it works.

AND - I got to fire it up! Figured out which is treble and which is bass control. One of the push/push knobs activates active or passive. The other... well, it doesn't seem to do much at this point (the push/push part, the knob I know). With the bass in passive mode, the treble and bass knobs don't seem to do anything. Kick in the active, and they both work as they should.

Blend knob works as it should, and by dumb luck I even wired it up correctly to get the neck pickup in "full" and the bridge pickup when you back it down all the way. (had a 50/50 shot, but you know how that goes!)

Can't wait to mount the neck to the bass, string it up, set it up, and give 'er a whirl!

Ah... tomorrow.