Larry carlton's show-Bud volume pedal

[tomo]

Do you have an idea of the circuit of larry carlton's show-bud volume pedal?

1. FET installd
2. it has gain adjust
http://personalpages.manchester.ac.uk/s ... es/FET.jpg

3. Rick Wheeler says that "boost highs as the volume is increased ..."
http://mr335.tv/?channel=rig&videofile= ... pedalboard

I have no idea about "boost highs as the volume is increased ..."
Do you have an idea?

[ampdork]

I believe it is simply the FET circuit from the amp put into pedal form so one can run long cables and such.
Dumble built John Mayer an "A-Box" which from the reports I have is also most likely the FET circuitry in pedal form (sans the volume pedal).
I built a "B-Box" for a fellow we'll see how he likes it soon enough.
I doubt that the sho bud actually "boosts" highs so much as just keeping the highs from being lost as per the original sho bud design. Likely with the FET before the volume pedal there are less losses. ;O)
That is how I hear the description anyway. Hearing it in action would tell more.

[Funkalicousgroove]

I looked in LC's volume pedal and it's not the same circuit as the FET.
I didn't have time to RI it, but I did turn them on to the Hilton volume pedal, which I believe they will be switching to.

An A-Box-later is a Mos-fet version of a Dumbleator, and I DOUBT dumble built John Mayer ANYTHING based on his affiliation with Two-Rock.

I know Alf Hermida builds him some boxes to reverse the phase of his signal when he plays certain amps.

[Funkalicousgroove]

FWIW, The Sho-Bud does seem to boost the high's the last few cm of travel, LC almost never puts it all the way forward.

[scotto]

I have an original Show Bud and it definately loses highs as you back off, similar to some guitar volume pots without a cap on them only it seems more pronounced. It's just a pot, so I would also guess that the new circuitry is probably meant to keep the tone flat.

[ampdork]

An A-Box-later is a Mos-fet version of a Dumbleator, and I DOUBT dumble built John Mayer ANYTHING based on his affiliation with Two-Rock.

I was skeptical as well but the source for that tid bit is solid as it gets.

What I thought funny is that ALL he got was a little box. I would be very surprised if he was not shooting much higher in his requests.

So while on the discussion of the obscure anyone have info regarding a circuit called "phase 4"?

[Funkalicousgroove]

Haven't heard that one yet, but I do have one of LC's sho-bud's on the way to me for repair, so we can get to the bottom of this.

[dogears]

Ahhh.... Glad we are all getting along again.

Join me for a chorus of Koombaya!!

[UltraHookedOnPhonix]

Kumbaya, my Lord, KUMBAYAAAAAAA!!!!!!!

Instead of being a passive volume control, Dumble probably modded it to be an active volume control to avoid tone loss. The large input impedance on the active Sho-Bud vs. the passive one would in all likelihood contribute to the brighter sound. Technically it’s not a buffer stage since it does offer gain and I would have to guess it’s either a FET or a MOSFET stage because they’re simple to set up and offer high input impedances.

Here’s a simple sketch:

[IMG:607:637]http://i205.photobucket.com/albums/bb17 ... TStage.jpg[/img]

Yeah, I know I'm preaching to the choir!

*****Just noticed it says, "new FET installed on the back"*****

[tomo]

Thank you!
I bought a sho-bud pedal.
I'll try it next week end.

[tomo]

I tried my sho-bud pedal.
I could understand what Brandon said. (boost high's the last few cm of travel.)

But my pedal has noise when I move pedal, so I want to replace pot.
The original pot is Allen-bradley 500kA, but it is hard to find now.
Which pot is good?
Please advise.

Brandon,
Did you get the bottom of LC's pedal?

[tonelab2]

I tried my sho-bud pedal.
I could understand what Brandon said. (boost high's the last few cm of travel.)

But my pedal has noise when I move pedal, so I want to replace pot.
The original pot is Allen-bradley 500kA, but it is hard to find now.
Which pot is good?
Please advise.

Brandon,
Did you get the bottom of LC's pedal?

I've had a couple of those shobuds over the years (sold one off many years ago) and found that it's common with most vol pedals to lose some highs when you back them off, similar to guitar vol control when backing off. Perhaps the pot needs a clean with electrical spray (deoxit, ect) to help get rid of noise.