Bourns Push Pull - issue and now baffled..

grappagreen

Hi all,

I've had a lot of fun recently rewiring and upgrading a couple of guitars. I'm getting to the point where I actually appear to understand what I'm doing and how guitar wiring works! May seem pathetic but after reading a load of stuff and experimenting it's just clicked and the fog lifted! 

I built a new scratch-plate this weekend for my SoCal (couple of Suhr Aldrich pickups, Bourns volume with treble pass & push/pull  with partial coil splits, 3 way switch) and all went well... except for some reason the volume pot seems intermittent. It seems to be a full volume irrespective of the pot position but then if I wriggle it a bit it starts to work (and then stops again). I've checked my wiring/work in detail and all looks fine. Everything meters correctly and I've been super tidy in my work. 

Could I have damaged the pot (or it have a fault) as I simply cannot work out what's going on and why it would fail to full volume and appear to bypass the pot..

Next on the list is an inductor based mid-range contour control! Who would have thought that this stuff could be so much fun and satisfying (excepting the above!).

Oh an one final question whilst I'm on it.. why do we use/require different resistor values for partial splits on a neck vs. bridge pickup? Answers beyond - they sound better would be helpful as I'm trying to understand what's actually going on

Any help appreciated.

Si

Jonathangus

@ICBM will confirm, but that sounds very much like the issue I had with my first wiring job.  If you're not careful, you can knacker the pot when you bend one lug to ground it to the casing.  Safer to connect the lug to the casing with a short wire.

grappagreen

Jonathangus said:

@ICBM will confirm, but that sounds very much like the issue I had with my first wiring job.  If you're not careful, you can knacker the pot when you bend one lug to ground it to the casing.  Safer to connect the lug to the casing with a short wire.

Thanks for the message... having learned the hard way this pot has the wire to connect the lug to ground.

ICBM

Even with a wire, the cause will be a bad ground connection to the bottom end of the pot track - that stops the pot turning down (it will get very slightly quieter, but not much). If you’re certain there’s no fault in the ground wiring, use a pair of fine-nose pliers to squeeze the rivet that attaches the terminal to the trackboard, so you’re clamping the terminal down harder. If that doesn’t fix it, the pot is knackered. (But still triple-check the rest of the wiring before you replace it.)

Winny_Pooh

I burnt out two Bourns pots....pissed because I wasn't particularly overdoing it. Was intermittent just like yours and probably the track contacting the pot casing. I bought another as I do love the low friction.

grappagreen

Thanks for the posts all..

I'll double check everything again and have ordered a couple more pots.

Si

hywelg

Do get the push push version, so much more user friendly

normula1

I couldn't find Bourns 500k push/push for love or money recently, they seemed to be on back order everywhere. I wasn't overly impressed with the Alpha equivalent..the latching was a bit iffy even before I put a knob in

grappagreen

hywelg said:

Do get the push push version, so much more user friendly

I wish I could find one I would much prefer a push/push style pot..

Changed the pot and appears to work now..