Adding buffer to passive volume pedal

[sjaustin]

Hey all, I'm trying to get this fairly simple thing to work, and I can't figure out what's going wrong. Thanks in advance for your advice!

What I want to do is add a dual output buffer to an Ernie Ball VP Jr. Here's what I did:

• I populated a PCB, tested that both outputs worked, and set to installing it.
• I installed a DC jack into the VP and connected PCB power and ground to it. (Also connected an LED/CLR.)
• I cut traces on the board that connect the IN jack to the tuner OUT jack and the volume pot.
• I connected the PCB input to the tip of the IN jack.
• I connected one output to the tip of the tuner OUT jack.
• I connected the other output to the PCB pad that is connected to the middle lug of the volume pot.
• I connected the DC jack sleeve to one of the I/O jack sleeves.

Now the pedal functions basically like an on/off switch. Heel down, it's off. As soon as I push the treadle forward at all, it comes in at full volume and stays there for the whole sweep. Any ideas or suggestions?

[Marshall Arts]

I think, that if you got the 250 k version, the pot should be in front of the buffer input (right behind the guitar).

[sjaustin]

I think, that if you got the 250 k version, the pot should be in front of the buffer input (right behind the guitar).

Ah, so then I'd need to connect the input to lug 2 of the pot and the outputs to the tips of the output jacks?

[Marshall Arts]

I think, that if you got the 250 k version, the pot should be in front of the buffer input (right behind the guitar).

Ah, so then I'd need to connect the input to lug 2 of the pot and the outputs to the tips of the output jacks?

I would guess input jack to lug 1 if lug 3 is Gnd. Lug2 to buffer Input, buffer output to output jacks.

[playpunk]

Hey all, I'm trying to get this fairly simple thing to work, and I can't figure out what's going wrong. Thanks in advance for your advice!

What I want to do is add a dual output buffer to an Ernie Ball VP Jr. Here's what I did:

• I populated a PCB, tested that both outputs worked, and set to installing it.
• I installed a DC jack into the VP and connected PCB power and ground to it. (Also connected an LED/CLR.)
• I cut traces on the board that connect the IN jack to the tuner OUT jack and the volume pot.
• I connected the PCB input to the tip of the IN jack.
• I connected one output to the tip of the tuner OUT jack.
• I connected the other output to the PCB pad that is connected to the middle lug of the volume pot.
• I connected the DC jack sleeve to one of the I/O jack sleeves.

Now the pedal functions basically like an on/off switch. Heel down, it's off. As soon as I push the treadle forward at all, it comes in at full volume and stays there for the whole sweep. Any ideas or suggestions?

I pulled the whole PCB out of the Ernie Ball VP I did this to. I put the buffer in front of the volume pot. I used the Aziltz/Coldcraft dual buffer board.

The volume swell worked perfectly on that pedal (until the string broke. I'ts still broken. I won't ever try to fix it again)

[sonnyboy27]

I put a single buffer before the volume pot. Sweep is still good. There's post in my blog about it. https://prentisseffects.blogspot.com/2017/01/ernie-ball-vp-jr-tone-suck-mod.html

It doesn't use a dual buffer but it works just as well. This is the method I've seen in a bunch of modded Ernie Ball VPs that I've fixed strings for.

[sjaustin]

I would guess input jack to lug 1 if lug 3 is Gnd. Lug2 to buffer Input, buffer output to output jacks.

This worked perfectly. Fixed the problems. Thanks!

I pulled the whole PCB out of the Ernie Ball VP I did this to. I put the buffer in front of the volume pot. I used the Aziltz/Coldcraft dual buffer board.

The volume swell worked perfectly on that pedal (until the string broke. I'ts still broken. I won't ever try to fix it again)

Let me know if you'd like to unload it! This job was for a friend, and I kinda want one for myself. I wouldn't mind trying the string replacement job.

[gordo]

String replacement is an adventure but I've done a whole bunch of them.  There are some really good videos of the process on the web.  I may have uttered a few streams of profanities from time to time.

[playpunk]

I would guess input jack to lug 1 if lug 3 is Gnd. Lug2 to buffer Input, buffer output to output jacks.

This worked perfectly. Fixed the problems. Thanks!

I pulled the whole PCB out of the Ernie Ball VP I did this to. I put the buffer in front of the volume pot. I used the Aziltz/Coldcraft dual buffer board.

The volume swell worked perfectly on that pedal (until the string broke. I'ts still broken. I won't ever try to fix it again)

Let me know if you'd like to unload it! This job was for a friend, and I kinda want one for myself. I wouldn't mind trying the string replacement job.

PM me your address and you can have the whole kit and caboodle. It seems like a cruel thing to ask for money for.