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Topic: Volume pot rate of change? |
Al Evans
From:
Austin, Texas, USA
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Posted 9 Apr 2018 8:26 am |
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What determines the rate of the change from inaudible to full volume in a volume control, e.g., a volume pedal with a potentiometer?
For example, let's say you have one that doesn't audibly increase the volume during the first third of its travel, then goes from quiet to maximum in the next third, and doesn't go any louder in the final third of its movement.
What causes this, and what can be done to spread out the volume increase over a wider range?
Thanks in advance,
--Al Evans
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2018 MSA Legend, 2018 ZumSteel Encore, 2015 Mullen G2, G&L S-500, G&L ASAT, G&L LB-100, Godin A4 Fretless, Kinscherff High Noon |
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Steven Paris
From:
Los Angeles
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Posted 9 Apr 2018 8:30 am
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Taper of the potentiometer.
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Emmons & Peavey |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 9 Apr 2018 9:16 am
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Most volume control pots are logarithmic taper, since perceptions of loudness occur that way.
Using a linear taper pot for volume control, often exhibits the symptoms you describe. |
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Al Evans
From:
Austin, Texas, USA
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Posted 9 Apr 2018 9:43 am
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| Bill A. Moore wrote: |
Most volume control pots are logarithmic taper, since perceptions of loudness occur that way.
Using a linear taper pot for volume control, often exhibits the symptoms you describe. |
I think you're right. I had assumed it was logarithmic, since it controls audio, but apparently I'm mistaken.
<shrug> That would explain it.
--Al Evans
_________________
2018 MSA Legend, 2018 ZumSteel Encore, 2015 Mullen G2, G&L S-500, G&L ASAT, G&L LB-100, Godin A4 Fretless, Kinscherff High Noon |
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Jack Stoner
From:
Kansas City, MO
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Posted 9 Apr 2018 10:00 am
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There are Linear (resistance) taper pots and Logarithmic (resistance) taper pots. There are also variants within the tapers.
"Audio" pots are logarithmic types. The old Allen Bradley (and Clarostat branded after they bought Allen Bradley) pots used in volume pedals was a "modified" logarithmic type. This is the reason the volume pedal pots sold today that are just a "logarithmic" do not work like the old Allen Bradley's did. I noticed a difference in an old Goodrich 120 Volume Pedal I have that had an Allen Bradley modified logarithmic pot that I finally had to replace with a new Dunlop volume pedal pot. It works but I'm not too thrilled with the taper in the pot. |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 9 Apr 2018 12:01 pm
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Like Jack said, only there are different taper "L" pots. Some Fender circuits call for a "J" taper which has about 30% resistance at half travel vs std, "L" taper which is 10-15%.
I was once told the old volume pedal pots were "J" taper, which explains what Jack has experienced. |
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George Kimery
From:
Limestone, TN, USA
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Posted 9 Apr 2018 12:13 pm Volume pot rate of change?
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| My 120 has an Allen Bradley pot that is stamped made in Mexico. Is this a later and inferior pot to the originals made in the USA and is it most likely a J taper or modified J taper? |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Steven Paris
From:
Los Angeles
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