Grateful Dead Music Forum

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 #127483  by James-T
 Fri May 03, 2013 10:15 pm
I've been having repeated hassles getting my Waldo buffer to work. My tech installed it in my PRS CU22 last fall and it went haywire and the volume pot became the tone pot and the tone pot stayed at 10.

I sent it back to Mike for diagnosis and received what looked like a new unit this winter. I just had it installed in a new guitar and got the guitar back,with a similar problem. This time the Volume pot is just fine, but the same problem with the tone pot.

What is my tech doing wrong on the install? Would the UGB affect the performance of the tone pot at all?

Any insight into this problem would be greatly appreciated.


 #127498  by milobender
 Sat May 04, 2013 7:38 am
I'd need to see a schematic of the way it's installed now to help... I've used many of Waldo's buffers and haven't had a problem with any of them. The UGB shouldn't have any effect on the performance of either the tone pot, or the volume pot.

 #127510  by James-T
 Sat May 04, 2013 10:33 am
Hey thanks Brian!

Here is a schematic I’ve cobbled together by studying the install done by my tech. I’m no electronics wiz, actually its all Greek to me so this is more of a picture than schematic.


Here is a “bigger picture” generic schematic I grabbed off the internet, that shows the basic setup in for my PRS.


Mike is also being supper helpful and asking some good questions.


 #127514  by BDI
 Sat May 04, 2013 11:31 am
Did the volume pot values get changed when you installed the UGB? Anything after the buffer's gotta be like 25k if I recall correctly.

 #127516  by James-T
 Sat May 04, 2013 12:04 pm
Good question. The volume pots would be standard for what is required for the active EMG's we pulled out. the guitar now has a Dual Sound at the neck and a Dragon II t the bridge. I'm not sure if they would be 25k.
 #127522  by milobender
 Sat May 04, 2013 2:49 pm
So are the pups you have in it now passive or active?

I can see by your drawing that the volume pot is not connected correctly. The left lug is correct, but the middle should just go to the tip of the jack/output, and the right lug looks to be correct. It should be a 25K pot... I would start with this first and see how it affects everything.

I would connect your tone pot to the main output of the switch (so it's before the buffer), together with the yellow wire to the UGB.

I can't tell from the drawing how your battery is connected, the output jack, and whether or not everything is grounded properly.
 #127624  by James-T
 Mon May 06, 2013 6:07 pm
Hey Brian,

Thanks so much for this, you were right on the money and so was Mike. My tech got the tone pot working today without issue. :hail:

I'm really looking forward to having the UGB in this guitar as it offers much more than just driving long runs of cables. It's added extra crispness and clarity to the pickups and given this guitar that signature Garcia tone. The pickups are passive and replaced the stock EMGs. I put a dual sound in the neck and moved a PRS Dragon II into the neck which I pulled out of my cu 22 (in favor of a bare knuckles stormy Monday which is a replica of a 65 PAF Gibson sg). The dual sound is a great next pick up. I think it's just as good as in the middle position.