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I'm making a Metal distortion pedal
ill be using 6 potentiometers
POT1 Distortion 250K
POT2 low freq control 100K
POT3 high freq control 100K
POT4 mid 100K
POT5 Gain 10K
POT6 volume 50k

But which type of potentiometer is suitable for each ?? Logarithmic? linear?

Distortion-Distortion effects create "warm", "dirty" and "fuzzy" sounds by compressing the peaks of an electric musical instrument's sound wave and adding overtones

Low, Mid, and High refer to the frequencies that effect the tone of the amp. Low being low frequency, Mid being middle frequencies, and High being High frequencies.

If you want your guitar tone to be bassy you'll turn up the Low, If you want it crisp or tinny you turn up the high. Mid frequencies generally are associated with clarity and definition or body of the tone. for example if you turned the Low and high up, and left the mid down, you'd get a boxy sound.

But i do not know which pot will achieve the required control over them LOG ? Linear? :(

Here is the circuit diagram

enter image description here

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    \$\begingroup\$ One that goes to 11. Log or Linear depends on the circuit you are using the pot in. If in doubt breadboard it with both types. \$\endgroup\$ – RedGrittyBrick Jul 12 '13 at 7:42
  • \$\begingroup\$ for example the log pot is excellent for volume. what about others? ill be buying them once i know which ones are required. \$\endgroup\$ – Metalhead1247 Jul 12 '13 at 8:19
  • \$\begingroup\$ @Metalhead1247 We really need the circuit in order to understand what's happening. For example, you mentioned that logarithmic potentiometers are excellent for volume. From purely electrical point of view, for volume control both types are completely equal. It's due to human perception of sound volume, that to us logarithmic potentiometers appear more natural for volume control. Same thing goes for other controls you mentioned. \$\endgroup\$ – AndrejaKo Jul 12 '13 at 9:48
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    \$\begingroup\$ I hope Olin does not see this question :) \$\endgroup\$ – abdullah kahraman Jul 12 '13 at 11:25
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    \$\begingroup\$ Here you go: electronics.stackexchange.com/a/28255/5035 \$\endgroup\$ – abdullah kahraman Jul 12 '13 at 12:05
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Well you can modify the linear pot to get an almost logarithmic response by adding a resistor from the CCW side to the wiper. Because of its simplicity this might be worth a try. Here's what the idea looks like: -

enter image description here

For the pedal circuit you need this might be ideal. It's not perfect of course but it reduces the risk of buying linear pots because these can be made "almost logarithmic by adding one resistor.

One thing to remember is that if the design calls for a 1M pot and you have a 1M resistor across wiper to CCW, the end to end pot value will change as the wiper advance towards CW. This would probably mean that you should use a 2M pot and 2M resistor.

Some experimentation is required and if you could post a circuit I'm sure better advise could be given. Pictures gleened from here

EDIT - picture of circuit attached with my best guess at log/lin: -

enter image description here

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  • \$\begingroup\$ i have posted the circuit diagram! ty! \$\endgroup\$ – Metalhead1247 Jul 12 '13 at 10:54
  • \$\begingroup\$ Could you add a link for those images? \$\endgroup\$ – m.Alin Jul 12 '13 at 11:20
  • \$\begingroup\$ mediafire.com/view/k1ag0nq64qdp9cu/mypedalcircuit.png \$\endgroup\$ – Metalhead1247 Jul 12 '13 at 11:25
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    \$\begingroup\$ @m.Alin link added as requested \$\endgroup\$ – Andy aka Jul 12 '13 at 16:17
  • \$\begingroup\$ @Andyaka i got the potentiometer codes but not the type.can you tell me which code represents linear/log/other type of pot? POT1 dist 250K A POT2 low 100K W POT3 high 100K W POT4 mid 100K W POT5 top 10K B POT6 volume 50k A \$\endgroup\$ – Metalhead1247 Jul 14 '13 at 5:31

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