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Vintage push-pull mod - again ?

Posted: Sun Mar 23, 2014 4:56 am
by devnulljp
I'm trying to do the vintage push-pull mod on my 4003, but am having trouble reconciling the diagram and various photos.
Similar to this thread: viewtopic.php?f=2&t=407098
I have the newer PotR pushpull pot with 3 lugs/2 lugs rather than the older style with the 6-lug box

I can't figure out which lug is which in this diagram and how to make it jive with the photo that PotR send me as well as the one in the above thread that has the cap across the two lugs of the bottom part of the push-pull switch

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I drew it out and soldered everything up, but obviously made a mistake somewhere as I got both pickups on all the time regardless of where the 3-way toggle switch was set :oops:

Could someone point me to how to finish this diagram?

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Thanks!

Re: Vintage push-pull mod - again ?

Posted: Sun Mar 23, 2014 2:21 pm
by johnallg
Alan, the .0047uF cap goes from the toggle switch to the volume pot for the bridge pickup. There is a red wire there originally. The new switch goes from the same place with red wires, i.e., from the toggle switch to one switch lug, the other red wire from the other lug to the volume pot.

Easily, just pull the red wire going from the toggle to the pot from the pot lug, solder it to the new switch lug. Take another red wire and solder it to both the new switch lug and the other end to the volume pot lug you unsoldered the first wire. Now solder the .0047uF cap, one end to the toggle switch lug the red wire going to the new switch is soldered to, and the other end of the cap to the volume pot lug the other red wire is soldered to.

Basically, the cap goes from the toggle switch to the volume pot, and the new switch goes to the same places. When the switch is open, the cap is in circuit and there is less bass output from the bridge pickup. When the switch is closed, it shorts out the cap and the pickup now goes directly to the volume pot and is full range with more bass frequencies.

Hope this clears it up for you.

Re: Vintage push-pull mod - again ?

Posted: Sun Mar 23, 2014 2:25 pm
by johnallg
Looking at your solder up job again, the switch will work like that, but I'm guessing you have the red wire ends going to somewhere they shouldn't. Recheck where the red wires from the new switch go and make sure one goes back to the toggle switch output and one goes to the treble volume pot input. There should be NO OTHER wire from the toggle switch to the volume pot, only the new wires, when the cap is where you have it. Also, that cap could be microphonic, being a ceramic. A poly cap would be better.

Re: Vintage push-pull mod - again ?

Posted: Sun Mar 23, 2014 6:31 pm
by devnulljp
OK, got it. Thanks!

I was missing a ground from the bass volume to the bass tone and was trying to wire the push/pull upside down.

I redrew how I've wired it.

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Re: Vintage push-pull mod - again ?

Posted: Mon Mar 24, 2014 10:07 am
by iiipopes
The simplest way is with the factory diagram:
http://www.rickenbacker.com/pdfs/19507.pdf
Note the comment around C3, the .0047 inline cap, "C3 is replaced by a shunt on newer models." All the push-pull has to do is be an SPST to bypass this cap. And that is what the factory does. Mr. JH is even known to say that on older basses, he bypassed the cap permanently with an aluminum chewing gum wrapper wrapped around the cap touching both leads.

Re: Vintage push-pull mod - again ?

Posted: Mon Mar 24, 2014 5:37 pm
by jps
iiipopes wrote:Mr. JH is even known to say that on older basses, he bypassed the cap permanently with an aluminum chewing gum wrapper wrapped around the cap touching both leads.
Is this good for bubblegum music?


Re: Vintage push-pull mod - again ?

Posted: Tue Mar 25, 2014 4:32 am
by devnulljp
iiipopes wrote:The simplest way is with the factory diagram:
http://www.rickenbacker.com/pdfs/19507.pdf
Note the comment around C3, the .0047 inline cap, "C3 is replaced by a shunt on newer models." All the push-pull has to do is be an SPST to bypass this cap. And that is what the factory does. Mr. JH is even known to say that on older basses, he bypassed the cap permanently with an aluminum chewing gum wrapper wrapped around the cap touching both leads.
My father used to do that with fuses in electrical plugs so they wouldn't keep blowing
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