Buffer and volume pedal compatibility

Dave Hepworth · Post by **Dave Hepworth** » 30 Aug 2022 3:08 pm

Hi Folks
Could someone please explain why when I use a buffer between guitar and volume pedal then the taper is totally wrong .....most of the volume increase is at the end of the travel and unusable .The pedal is an ernie ball side loading model ....old but is mint unused condition.
When just guitar to pedal the taper is fine.I am using a peavey vegas amp .If I plugged the guitar into the buffer and then straight into the amp and use the in and out on the front would this bring the taper back to how it should be.If not what is the remedy please ?

Mike Bacciarini · Post by **Mike Bacciarini** » 31 Aug 2022 5:13 am

I believe that the buffer should be after the volume pedal. The pickup output presents a high impedance signal to the volume pedal and makes it happy, whereas the buffer output presents a low impedance signal. PSG > Vol Pedal > any FX pedals > then to the amp. See how that works....

Donny Hinson · Post by **Donny Hinson** » 31 Aug 2022 5:29 am

If the buffer you're using is amplifying the signal, then that would make the taper seem different. Try turning the amp up or down and see how that affects the taper.

Jack Stoner · Post by **Jack Stoner** » 31 Aug 2022 5:42 am

What buffer do you have?

I have a Goodrich MatchBro (dobro simulator) that is designed to be connected between the steel and volume pedal. It has a mini "Matchbox" which is a buffer with low impedance on the output. I see no difference in volume pedal operation, either a Goodrich pot pedal or an electronic VP such as a Hilton or Telonics.

Most Ernie Ball's, from what I see posted have a 250K pot, where the steel guitar VP's use a 500K (audio taper) pot. The pot resistance difference could be the problem as a volume pedal (properly wired) is a "variable" voltage divider.

Richard Sinkler · Post by **Richard Sinkler** » 31 Aug 2022 7:40 am

Curiosity question: Can the 250k ohm pot in an Ernie Ball pedal be changed to a 500K pot? My assumption in yes. Reason for asking is that along with the Dekley PSG and NV112, I got a beat up EB pedal. Wouldn't mind fixing it up for a spare.

If so, the OP might consider changing out the pot.

Mike Bacciarini · Post by **Mike Bacciarini** » 31 Aug 2022 8:48 pm

I put a Dunlop 470k pot in my VPJR and love it.

Dave Hepworth · Post by **Dave Hepworth** » 10 Sep 2022 8:04 am

I replaced the pot with a 100k and it seems to have cured the taper issue going straight into amp ( buffered with the new Fender "set level and buffer" unit )
Also with the old pot by using the in / out at front of Vegas that also cured the taper as well .

Brad Sarno · Post by **Brad Sarno** » 10 Sep 2022 9:14 am

that weird taper behavior kinda suggests the volume pedal is wired or connected backwards.

It should behave with the exact same taper regardless of a buffer there or not.

B

Dave Hepworth · Post by **Dave Hepworth** » 11 Sep 2022 2:09 am

Thanks for all the replies.Could I ask you Brad....if I wanted to convert say a 500K pot to low impedance can it be done by putting a resistor in parallel to drop the value accordingly. Would it go between the input lug on the pot and earth ? Thanks in advance.

Don Griffiths · Post by **Don Griffiths** » 2 Oct 2022 10:22 am

Richard Sinkler wrote:Curiosity question: Can the 250k ohm pot in an Ernie Ball pedal be changed to a 500K pot? My assumption in yes. Reason for asking is that along with the Dekley PSG and NV112, I got a beat up EB pedal. Wouldn't mind fixing it up for a spare.

If so, the OP might consider changing out the pot.

Yes Richard, I forgot where I got the last pot I bought.Probably from
Tom Bradshaw. The last time I broke a 12 year old rigging string a got some extras as well.

Donny Hinson · Post by **Donny Hinson** » 2 Oct 2022 3:10 pm

Dave Hepworth wrote:....if I wanted to convert say a 500K pot to low impedance can it be done by putting a resistor in parallel to drop the value accordingly. Would it go between the input lug on the pot and earth ? Thanks in advance.

Putting a fixed resistance in parallel will change the taper action of the pot, as well as the volume level.

Philip Mitrakos · Post by **Philip Mitrakos** » 3 Oct 2022 6:03 pm

Tommy Shown · Post by **Tommy Shown** » 17 Oct 2022 2:26 pm

I use the black box and I go out the guitar to the input of the bb
Out the black box to the volume pedal.

Philip Mitrakos · Post by **Philip Mitrakos** » 17 Oct 2022 2:57 pm