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previous: frank Hi, I’m looking to get a volume ped... -- 1/5/2000 3:26 PM

Re: Volume pedal questions

1/5/2000 4:37 PM
Mark Hammer	Re: Volume pedal questions Wise choice of a volume pedal depends on your intended use. If you like to use your volume pedal in a set-and-forget manner, then the needs are somewhat less demanding. If you intend to use your volume pedal actively, for swell, backwards tape or pedal steel effects, then you will want someting that stands up a bit better, results in longer periods of clean scratch-free use, and provides good physical feedback. Opinions vary, but I suspect that the physical feel of a pedal plays a role in coordinating one's use of it, much the same way that keyboardists play differently on cheesy plastic keyboards than they do on a properly weighted piano mechanism. The Ernie Ball and Goodrich volume pedals are considered by many to be the top of the line. The Ernie Ball uses a regular pot but uses a cable-and-pulleys arrangement to turn the pot, identical to the cable-and-pulleys arrangement used by many non-digital radio tuners. The Goodrich uses an optical system. Both tend to result in smoother volume swells and less pot-noise. In the case of the Ernie Ball, the reduction in pot noise is simply because the pedal mechanism is more indirectly coupled to the pot than the more standard rack and pinion gear mechanism (standard on wahs) is. In the case of the Goodrich, there IS no pot. The Goodrich, being and active system, needs batteries. I'm partial to the Ernie Ball because the physical feedback it provides permits extremely smooth swells and encourages active use of the voume pedal. The Goodrich, I am less familiar with. Other contenders include these: 1) Roland/BOSS made a potless Hall effect pedal. The Hall effect refers to the production of a voltage as a magnet comes in proximity with the circuit. This pedal simply moved a magnet as you sweep the pedal, hence no pot noise. Not familiar with this one, but the size of it (small) suggests to me that the physical feedback aspect will be wanting. I may be dead wrong, though. Active. Requires batteries. 2) Craig Anderton published a "volume pedal retrofit" circuit in GP many years ago (reprinted in his last DIY Projects book, and scans are likely available on the net) that used the existing volume pot in standard commercial pedals to control a VCA. The additional circuitry smoothed out the volume swell so that even if the pot was scratchy, you wouldn't hear it. I built a stereo one for a buddy who wanted to pan between synths, and it worked fine. Relatively quiet. Needs batteries. Regardless of whatever pedal you might get, it is generally preferred that the pot be a relatively high value. Something at least as high as your guitar's volume pots (250-500k) or higher (1M) would be desirable to prevent high end loss and overall signal loss. If the music store doesn't know, you can always bring a meter, stick a patch cord in the input and measure the DC resistance between input and output. It's possible the full depression of the pedal does not result in rotating the pot ALL the way to the end, but at least you'll have an idea (e.g., if full "on" reads 410k, it's probably a nominally 500k pot). Also bear in mind that simple volume pots can be tapered to provide different and custom tailored "feels". For this, I suggest you look at the papers on pots at either RG Keen's GEOFEX site, or the one at Jack Orman's AMZ site. Finally, people generally don't like single pot passive systems because they lose a bit of high end as you turn down. This can be partially remedied the same way it is on Fender guitars and amps, via a small value bypass capacitor between input and wiper on the pot. From your desire to have a tuner out, you might be better served by wiring up your own circuit and installing it. Alternatively, stick a transformer or active splitter ahead of the pedal. Passive pedals (and the Ernie Ball one is too) tend to benefit by having some buffering ahead of them anyways. Best of luck. Hope you find a keeper.

1/5/2000 4:37 PM

Mark Hammer

Re: Volume pedal questions

Wise choice of a volume pedal depends on your intended use. If you like to use your volume pedal in a set-and-forget manner, then the needs are somewhat less demanding. If you intend to use your volume pedal actively, for swell, backwards tape or pedal steel effects, then you will want someting that stands up a bit better, results in longer periods of clean scratch-free use, and provides good physical feedback. Opinions vary, but I suspect that the physical feel of a pedal plays a role in coordinating one's use of it, much the same way that keyboardists play differently on cheesy plastic keyboards than they do on a properly weighted piano mechanism.

The Ernie Ball and Goodrich volume pedals are considered by many to be the top of the line. The Ernie Ball uses a regular pot but uses a cable-and-pulleys arrangement to turn the pot, identical to the cable-and-pulleys arrangement used by many non-digital radio tuners. The Goodrich uses an optical system. Both tend to result in smoother volume swells and less pot-noise. In the case of the Ernie Ball, the reduction in pot noise is simply because the pedal mechanism is more indirectly coupled to the pot than the more standard rack and pinion gear mechanism (standard on wahs) is. In the case of the Goodrich, there IS no pot. The Goodrich, being and active system, needs batteries. I'm partial to the Ernie Ball because the physical feedback it provides permits extremely smooth swells and encourages active use of the voume pedal. The Goodrich, I am less familiar with.

Other contenders include these:
1) Roland/BOSS made a potless Hall effect pedal. The Hall effect refers to the production of a voltage as a magnet comes in proximity with the circuit. This pedal simply moved a magnet as you sweep the pedal, hence no pot noise. Not familiar with this one, but the size of it (small) suggests to me that the physical feedback aspect will be wanting. I may be dead wrong, though. Active. Requires batteries.

2) Craig Anderton published a "volume pedal retrofit" circuit in GP many years ago (reprinted in his last DIY Projects book, and scans are likely available on the net) that used the existing volume pot in standard commercial pedals to control a VCA. The additional circuitry smoothed out the volume swell so that even if the pot was scratchy, you wouldn't hear it. I built a stereo one for a buddy who wanted to pan between synths, and it worked fine. Relatively quiet. Needs batteries.

Regardless of whatever pedal you might get, it is generally preferred that the pot be a relatively high value. Something at least as high as your guitar's volume pots (250-500k) or higher (1M) would be desirable to prevent high end loss and overall signal loss. If the music store doesn't know, you can always bring a meter, stick a patch cord in the input and measure the DC resistance between input and output. It's possible the full depression of the pedal does not result in rotating the pot ALL the way to the end, but at least you'll have an idea (e.g., if full "on" reads 410k, it's probably a nominally 500k pot).

Also bear in mind that simple volume pots can be tapered to provide different and custom tailored "feels". For this, I suggest you look at the papers on pots at either RG Keen's GEOFEX site, or the one at Jack Orman's AMZ site.

Finally, people generally don't like single pot passive systems because they lose a bit of high end as you turn down. This can be partially remedied the same way it is on Fender guitars and amps, via a small value bypass capacitor between input and wiper on the pot.

From your desire to have a tuner out, you might be better served by wiring up your own circuit and installing it. Alternatively, stick a transformer or active splitter ahead of the pedal. Passive pedals (and the Ernie Ball one is too) tend to benefit by having some buffering ahead of them anyways.

Best of luck. Hope you find a keeper.