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Topic: Volume pedal verification with measurement (DC resistance) |
T. C. Furlong
From:
Lake County, Illinois, USA
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Posted 15 May 2018 3:24 pm |
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| I hope that someone can shed some light on this question that I have about volume pedals. I took out my trusty Fluke digital multi-meter to see how all six of my potentiometer volume pedals compared. They were all over the map with a DC resistance measurement. Can someone explain what the ideal measurement should be with the pedal wide open (full volume) and what it should be with the pedal all the way off (no volume) And where do you measure? I realized that I probably have a gap in my understanding of how a pot pedal is supposed to be adjusted. Thanks in advance! TC |
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Paul Arntson
From:
Washington, USA
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Posted 15 May 2018 4:15 pm
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http://generalguitargadgets.com/pdf/ggg_dearm_vol_sc.pdf
If your pedal is wired like this:
With nothing plugged into the output, measuring across the input should be a constant fairly hi reading
With nothing plugged in the input, measuring across the output should go from pretty low at zero volume up to near the "fairly hi reading" noted in the previous measurement.
_________________
Excel D10 8&4, Supro 8, Regal resonator, Peavey Powerslide, homemade lap 12(a work in progress) |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 15 May 2018 7:31 pm
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| Also, it's good to keep in mind that differences of 10%-20% aren't significant, so a pot that reads a few thousands of ohms higher or lower does not matter. In other words, a reading of 470k is well within tolerance for a 500k pot. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 15 May 2018 7:44 pm
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| Quote: |
| I realized that I probably have a gap in my understanding of how a pot pedal is supposed to be adjusted. |
Adjusted for what? Many are not adjustable at all except for physiczlly moving the string or gear(s) - see below -
There are no real standards for "lowest level" (which is rarely all the way off) or highest (which isn't usually the same as a straight cable. And "pot" pedals can use pots of several different impedance standards - other circuitry, even in a passive (non-powered) pedal requires different pot values.
Pedals also vary in "sweep" - how quickly they go from zero to full and whether they go somewhat smoothly or quickly at a specific, small range in the middle (more or less) of the sweep.
All these variables are worked out by each designer - and again, there's no "standard". Many are not even adjustable other than string (or gear) tension or where the mechanism is set as far as a start and end point. This can involve physically repositioning the string or gear.
This is why it's not unusual to find different readings in different pedals.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Glenn Demichele
From:
(20mi N of) Chicago Illinois, USA
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Posted 15 May 2018 8:05 pm
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What Paul said, with these additions=>
"With nothing plugged into the output, measuring across the input should be a constant fairly hi reading"
=>regardless of the position of the pedal. Measuring from tip to sleeve of the input jack. Pots are usually +/10% tolerance.
With nothing plugged in the input, measuring across the output should go from pretty low at zero volume up to near the "fairly hi reading" noted in the previous measurement.
=>Measuring from tip to sleeve of the output jack. Note that depending on the adjustment of the string, you can only go from above the minimum to below the maximum because the pedal throw is usually less than the full pot rotation or you'll slam into the pot mechanical stops and break the pot. I usually set mine so it goes all the way up, but not all the way down.
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Franklin D10 8&5, Excel D10 8&5, homemade buffer/overdrive, Moyo pedal, GT-001 effects, 2x BAM200 for stereo. 2x GW8003 8" driver in homemade closed-box. Also NV400 etc. etc... |
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Paul Arntson
From:
Washington, USA
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Posted 16 May 2018 10:15 am
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Thanks,Glenn. Good clarification.
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Excel D10 8&4, Supro 8, Regal resonator, Peavey Powerslide, homemade lap 12(a work in progress) |
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Bill Bassett
From:
Papamoa New Zealand
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Posted 23 May 2018 8:43 am Now I'm Curious
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Trying to compare 2 V pedals, my ear may not discern well enough. So, I think I'll cobble together an experiment.
Find a source for a stable tone, like a keyboard with middle C held down.
Run it into an old device with a VU meter. Old Tape recorder will do just fine.
Calibrate the tone to 0 db.
Then insert the VP in between. And watch the VU meter do its thing. Full on should be 0 db +-. If not, fiddle with it till it is.
Check the other VP the same way.
No need to measure ohms when all you really want is consistency, right? I just wish I hadn't given away my old Casio. |
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