Emmons Volume Pedal Wiring?

Bob Snelgrove · From: san jose, ca

Hi Guys

My wife was helping me solder in a new pot and she unsoldered the wires before marking them. Is there a diagram somewhere to check? The pedal works but only with the in/out reversed, but seems a little brighter than my Goodrich pedal. The pot is a Goodrich pot, 500k.

thx

bob

C Dixon · From: Duluth, GA USA

ok Bob,

The input jack's hot lead goes to the ungrounded outside leg of the pot. The center of the pot goes to the output jack's hot connector. The third leg of the pot goes to ground. If your volume pedal then works backwards (louder when up), then reverse the outer legs.

carl

[This message was edited by C Dixon on 25 March 2004 at 06:51 PM.]

Bob Snelgrove · From: san jose, ca

Thanks, Carl

On my output jack, the ground lug goes to chassis. On the pot, one of the wires goes to the ground lug on the input jack. Does that sound right?

thx

bob

C Dixon · From: Duluth, GA USA

Yes,

One outside leg of the pot always goes to ground. As does the "sleeve" part of the Jacks.

Note: if the wrong leg of the pot gets grounded, the pedal will work backwards. This is what Jerry Byrd does to every new pedal he buys. Because he wants it to increase volume moving up instead of down like the rest of us.

So he simply reverses the ground leg with the other outside leg of the pot.

carl

John Bechtel · From: Nashville, Tennessee, R.I.P.

It seems to me that the better/easier/more practical way to determine which way is OFF or ON would be to simply reverse the direction in which the cord is wrapped around the shaft. That way the taper of the pot will be preserved properly. If you simply reverse the outside wires, won't the shelving of the pot be in he beginning of the travel rather than the end of the travel? (unless maybe you're using a Linear-Pot!) Knowing very little about electronics, I have always been under the impression that there is only one proper way to wire a pot! Although reversing Terminals 1 & 2 will reverse the taper. Teach me something!

------------------
“Big John” Bechtel
Franklin PSG D–10 (9 & Cool

Fender ’49–’50 T–8 Custom
Fender ’65 Reissue Twin-Reverb Custom™ 15”
http://community.webtv.net/KeoniNui/BigJohnBechtels

Brad Sarno · From: St. Louis, MO USA

Wow, cool. Jerry Byrd uses his volume pedal backwards? Back-louder, forward-softer? Weird. I once heard of an organist who liked it that way. He said that it's like his toe was covering a hole where the sound came out. If he lifted his toe, more sound got out. If he stepped on the hole, he shut it up.

Brad Sarno

C Dixon · From: Duluth, GA USA

Brad,

Not only does he wire it backwards, but he uses it on his left foot. Drives me crazy to watch him. But it works flawlessly for him; and has "forever" almost. He has to have one of the most fluid volume pedal actions (commensurate with the above anamoly) I have ever seen. It is poetry in motion IMO.

John,

Putting the string on backwards would cause some binding in some volume pedals. Also, a linear taper causes the human ear to perceive a log change in sound level. A log taper causes humans to perceive a linear change in sound level.

Which is just the opposite from what humans would normally think. This is because it takes 10 times the amount of change in sound level for a human ear to perceive a doubling (or halving) of sound level. Thus a log taper pot solves this perceptual phenomenon. IE, at mid position the human ear perceives half the level of wide open.

Incidently this is NOT the case with tone. Only level. But by using log tapered tone pots, Fender caused the player to perceive the tone controls worked better. Since MOST of their change occurs in the first few degrees of rotation. Try them and see for yourself! Most others used linear tapered tone pots. Joe used a linear taper volume pot and log tapered tone pots on his amps. Joe Fender was indeed a marketing genious.

Jack (Byrd), can you please verify whether Jerry rewires the pot; OR changes the direction of the string. I have always heard he simply rewires it. Enguiring minds want to know.

carl

C Dixon · From: Duluth, GA USA

Bob,

Thought this might help also. While it is of a Fender tone volume pedal wiring, IF you forget about the wires to the tone pot (the bottom one), it is wired identical to the Emmons pedal.

Incidently, the little triangles represent "ground".

Good luck friend,

carl

[This message was edited by C Dixon on 26 March 2004 at 04:14 PM.]

Vernon Hester · From: Cayce,SC USA, R.I.P.

Pots are manufactured to operate clockwise, So the various tapers (signal curves) start from CCW position to CW. If you hold the pot by the shaft and look down, the Guitar hot lead (signal) connects to the left terminal, The amp out to the center terminal,Both shields (grounds) to the right terminal. You can alter the curves with resistors.
Vern

John Bechtel · From: Nashville, Tennessee, R.I.P.

Vern;
I guess that is what causes me to think that JB simply reverses the cord on the shaft. Even if he doesn't, that's the way I would do it!

------------------
“Big John” Bechtel
Franklin PSG D–10 (9 & Cool

Fender ’49–’50 T–8 Custom
Fender ’65 Reissue Twin-Reverb Custom™ 15”
http://community.webtv.net/KeoniNui/BigJohnBechtels

Vernon Hester · From: Cayce,SC USA, R.I.P.

Some Jerry's answer.
I use the same pot for tone and volume. I just buy two of them if I want to change them. I use the 500meg audio taper for both tone and volume.
Some have asked about Jerry’s volume pedal and how he plays when using it. Here is his reply.
The pedal I use is made to my specifications. It works in reverse to how an accelerator in a car works. You go from pushing all the way down to turn it off and as you are releasing it coming back the volume comes on. It is a 500 meg. audio taper. There are two tapers, linear and audio- linear has no sweep, it comes on in just a little stroke where audio is general from nothing to wide open in one gradual sweep. That is what I have always used.
I pick it when I play it, I don’t pick it with it all the way off usually. I do sometimes depending on what I am playing but mostly I want the attack to be heard, but I’ll cut down the volume on the attack and let it swell as dynamics. Pedal players turn it clear off, pick it and turn it back on, a lot of them anyway, and you never hear the attack, squeezing each note. They can do that with the short stroke volume pedal they use with a linear taper.

earlier post about Jery Byrd's footpedal

C Dixon · From: Duluth, GA USA

Jerry discussed linear and audio tapers. I will add to this.

IF you have a volume pot that is a linear type, the volume WILL increase (or decrease) evenly and linearly from one end to the other. However, a human will NOT perceived this to be the case. IE, at half rotation, the listener does NOT perceived half the volume.

This is due to the fact that it takes 10 times the amount of change (log10) in level, for a human to sense twice the change.

This phenomenon is caused by the way the human ear/brain perceives sound. So, to get around this, and have a volume pedal sound linear as it sweeps, it MUST have log taper.

As to tone, this does problem does not happen. IE, a linear taper tone pot sounds like a linear change in tone by humans. (Albeit, humans hear a fall off in level as the sound becomes ever more bassy. Thus the reason for "loudness" controls on hi-end stereos.)

But in Jerry's case, this creates another problem. Because he mastered the art of the "boowah" sound, it is necessary (in his case) that MOST of the change occur quickly. So by using a log pot, it is perceived to have a guick (log) change in tone as it is rotated.

For most, we prefer a linear taper tone pot and a log taper volume pot. This makes BOTH volume AND tone sound linear as the pots are rotated.

carl

[This message was edited by C Dixon on 03 April 2004 at 07:52 AM.]

Bob Snelgrove · From: san jose, ca

Carl

Please explain the difference between linear and audio? Which do we use in our standard pedals? The old A/B pot in my emmons pedal comes on too quickly. Not scratchy but from off to full just pushing it slightly?

thx

bob

Rick Aiello · From: Berryville, VA USA

I've always used my VP "in reverse" ...

With my Goodrichs ... I rewind the cord ... I've never changed the ground ...

This allows me to adjust the "hex shaft sleeve" so that the "off position" (down) is exactly were I want it (letting some signal through ... not totally off).

Keith Hilton built me one of his ... in reverse. Now a simple turn of the dial lets me set the "come on" ... Its GREAT !!!

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www.horseshoemagnets.com

C Dixon · From: Duluth, GA USA

Bob,

The terms linear and audio should be linear and log. Audio and log are used interchangably.

If you use a linear pot in your volume pedal. It will go from little or no volume to full volume in just few degree of rotation. If you use an audio (log) pot, there will be a gradual and even increase in volume all the way from off to full on.

Note: the level is NOT changing gradually with a log pot, but humans perceive that it is.

When God created humans, he made some incredibly wonderful things. Of course one of these is the human ear. Because it can hear things that even a microphone cannot pick up; and yet hear the loudest sounds (until the ear is damaged), God chose to make the range NON linear in perception.

There are very good scientific reasons for this. But it ends up causing the phenomenon discussed above. There is nothing man has ever created (in one device) that has the range of the human ear.

Interestingly the eye is 1000 times more capable than the human ear. We were created by a genious that has NO equal in this universe. But then of course that is why he is called omnipotent.

Remember to proclaim him always,

carl

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