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Is this Schematic Correct?

PortlandBass77

PortlandBass77

Jul 11, 2013
4,827
4,021
Portland, OR
www.youtube.com
#1
So this is the first schematic I have ever drawn up. It is for a bass I am building this summer and is pretty complex:

So there will be 3 P pickups (bridge, middle, and neck), with each having it's own series/parallel 2 way switch. The bridge pickup will go to a tone pot wired so that the bass instead of treble is cut (in series?). I am doing this so that I can solo the bridge to sound like a guitar for a bass + drum project. The middle and neck pickups will each have a separate volume pot and 1 standard tone pot for the 2 (wired like a jazzzzz bass). There will also be a Rickenbacker style stereo output that allows all 3 pickups through the output on the bridge side when no cable is inserted into the output on the neck side. When a cable is inserted to both of the outputs, the bridge side is the bridge pickup only and the neck side is the neck and middle pickup. Please do not go easy on me. This being my first schematic I expect it to have many mistakes or inefficiencies:

S1 = bridge PU series/parallel switch
S2 = middle PU series/parallel switch
S3 = neck PU series/parallel switch
V1 = bridge volume
v2 = middle volume
V3 = neck volume
T1 = bridge tone (wired in series i think? it's supposed to cut bass)
T2 = middle + neck tone (standard wiring)
O1 = output 1 (bridge only or all 3 PUs)
O2 = output 2 (neck + middle)

schematic.png
 
#3
There are several problems.

Firstly, the series/parallel switching is not done properly. Series mode does nothing, and parallel mode shorts the coils out. This can be corrected by observing the proper wiring for series/parallel switches.

Second, the bridge pickup's volume pot is wired backwards. That is the way that master volume pots are wired, but it will not work when there are multiple volume pots with no pickup switching, because adjusting the volume when all three pickups go to one output will cause all pickups to be affected. This can be corrected by switching the first and second terminals on the pot. (That would be the middle terminal, and the one that is not the ground.)

Third, the bridge pickup's tone pot is not wired to cut bass. For that, you would have the signal going to one of the terminals, and the output to another, with the third terminal left open. The capacitor would then be placed across two terminals.

Fourth, your output jack wiring is unclear. You have stated Rickenbacker wiring, and then also something different. Rickenbacker wiring has one TRS "stereo" jack with a signal on the tip and a signal on the ring, and then one TS "mono" output that combines the signals when a jack is inserted. This kind of wiring requires a TRS "stereo" jack, as well as a TS "mono" jack that has a terminal which only makes contact with the tip, when a cable is inserted. The kind of wiring you mentioned has two TS "mono" outputs, where the two signals combine to one jack if there is a cable in only one of the jacks. This is done with two TS "mono" jacks, with "break" terminals that only connect to the tip terminal when no cable is inserted. What you have shown is two identical TRS "stereo" jacks with one signal on the tip, and the other on the ring, and no switching. Before this can be corrected, you need to clarify your intention for the jacks, but if you want the dual mono jacks, just connect the tip terminal of jack one to the break terminal of jack two, and vice versa.

As a side note, I can't imagine three series/parallel switches in a triple split coil bass being useful, but that's just me.
 
Last edited:
#4
Firstly, the series/parallel switching is not done properly. Series mode does nothing, and parallel mode shorts the coils out. This can be corrected by observing the proper wiring for series/parallel switches.

Second, the bridge pickup's volume pot is wired backwards. That is the way that master volume pots are wired, but it will not work when there are multiple volume pots with no pickup switching, because adjusting the volume when all three pickups go to one output will cause all pickups to be affected. This can be corrected by switching the first and second terminals on the pot. (That would be the middle terminal, and the one that is not the ground.)

Third, the bridge pickup's tone pot is not wired to cut bass. For that, you would have the signal going to one of the terminals, and the output to another, with the third terminal left open. The capacitor would then be placed across two terminals.

Fourth, your output jack wiring is unclear. You have stated Rickenbacker wiring, and then also something different. Rickenbacker wiring has one TRS "stereo" jack with a signal on the tip and a signal on the ring, and then one TS "mono" output that combines the signals when a jack is inserted. This kind of wiring requires a TRS "stereo" jack, as well as a TS "mono" jack that has a terminal which only makes contact with the tip, when a cable is inserted. The kind of wiring you mentioned has two TS "mono" outputs, where the two signals combine to one jack if there is a cable in only one of the jacks. This is done with two TS "mono" jacks, with "break" terminals that only connect to the tip terminal when no cable is inserted. What you have shown is two identical TRS "stereo" jacks with one signal on the tip, and the other on the ring, and no switching. Before this can be corrected, you need to clarify your intention for the jacks, but if you want the dual mono jacks, just connect the tip terminal of jack one to the break terminal of jack two, and vice versa.

As a side note, I can't imagine three series/parallel switches in a triple split coil bass being useful, but that's just me.[/QUOTE]

First: Here are the schematics I based this off of: [Invalid or Expired Link Removed]
http://www.guitar-mod.com/wiring/pbass_4conductor.gif and
Invalid Link Removed

Second, I want the jack to be just like a Ric-o-output with one output for all the pickups when only one cable is plugged in and the second for the bridge pu only when a cable is plugged in. Is it possible to do this with only TRS stereo output jacks? I just ordered a ton of trs jacks out of bad advice it seems.

Third: I will re-wire the series/parallel switches and the pots to the best of my ability later tonight then upload an update. Also I just realized, shouldn't the middle and neck volume pot be sent to the tone separately instead of like the jazz wiring?
 
#5
PortlandBass77 said:
First: Here are the schematics I based this off of: [Invalid or Expired Link Removed]
http://www.guitar-mod.com/wiring/pbass_4conductor.gif and
Invalid Link Removed
Click to expand...

You did not follow the series/parallel switching wiring or the bass cut pot wiring shown in those links. Look over those diagrams again and compare with your diagram.
Also, as I said, the bridge pickup's volume pot cannot be wired as shown in the P bass diagram, since there will be multiple volume pots in mono mode.

PortlandBass77 said:
Second, I want the jack to be just like a Ric-o-output with one output for all the pickups when only one cable is plugged in and the second for the bridge pu only when a cable is plugged in. Is it possible to do this with only TRS stereo output jacks? I just ordered a ton of trs jacks out of bad advice it seems.
Click to expand...

This is not how Rickenbackers are wired. Rickenbackers have a mono output on one jack, and a stereo output on the other jack, which requires the use of a stereo cable. If you want one mono output for all pickups, and a second mono output for only the bridge pickup, you will need one standard TS "mono" jack, and one TS "mono" jack equipped with a break terminal. The neck/middle pickups' output will go to both the standard jack's tip terminal, and the other jack's break terminal. Then, the bridge pickup's output will go to the tip terminal of the jack that has the break terminal.

PortlandBass77 said:
Third: I will re-wire the series/parallel switches and the pots to the best of my ability later tonight then upload an update. Also I just realized, shouldn't the middle and neck volume pot be sent to the tone separately instead of like the jazz wiring?
Click to expand...

There is only one possible way to wire two volume pots into one tone, and that is the way you have shown.
 
#6
line6man said:
This is not how Rickenbackers are wired. Rickenbackers have a mono output on one jack, and a stereo output on the other jack, which requires the use of a stereo cable. If you want one mono output for all pickups, and a second mono output for only the bridge pickup, you will need one standard TS "mono" jack, and one TS "mono" jack equipped with a break terminal. The neck/middle pickups' output will go to both the standard jack's tip terminal, and the other jack's break terminal. Then, the bridge pickup's output will go to the tip terminal of the jack that has the break terminal.
Click to expand...

But is their any possible way to wire the output using only trs stereo output jacks?
 
#7
PortlandBass77 said:
But is their any possible way to wire the output using only trs stereo output jacks?
Click to expand...

The only thing you can do with two stereo jacks is what you've shown in the diagram. That gives the neck/middle output on the tip, and the bridge output on the ring. Or the other way around. Or one jack one way, and the other jack the other way. If you want to be able to do a standard output on a mono instrument cable, you will either need the jacks I mentioned, or some switches.
 
#8
line6man said:
The only thing you can do with two stereo jacks is what you've shown in the diagram. That gives the neck/middle output on the tip, and the bridge output on the ring. Or the other way around. Or one jack one way, and the other jack the other way. If you want to be able to do a standard output on a mono instrument cable, you will either need the jacks I mentioned, or some switches.
Click to expand...

Would 2 way switches work? I have plenty of those. Also thanks a lot for the advice! You have been very helpful.
 
#10
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