Volume Pot Issue- Uneven fading

[stomp]

So i just finished my first build, and all is great, except for an issue with my sole volume knob. While it does technically work, about 80% of the volume swell takes place in the last quarter or so of the rotation (or the first quarter when turning the volume down). Does this sound like a faulty pot or might I have wired in something wrong?

 

[bagman67]

So i just finished my first build, and all is great, except for an issue with my sole volume knob. While it does technically work, about 80% of the volume swell takes place in the last quarter or so of the rotation (or the first quarter when turning the volume down). Does this sound like a faulty pot or might I have wired in something wrong?

Could be that you have a linear rather than an audio taper pot.  From a human perspective, a linear pot will tend to sound like all the real change in volume is at the first few degrees of the pot's rotation. 

Or it could be broke.

 

[The Norwegian Guy]

I have the same issue.
Which pots are the best ones to use?

 

[bagman67]

Audio taper for volume.  Tone, probably the same, but I'll defer to other resident experts.

 

[line6man]

So i just finished my first build, and all is great, except for an issue with my sole volume knob. While it does technically work, about 80% of the volume swell takes place in the last quarter or so of the rotation (or the first quarter when turning the volume down). Does this sound like a faulty pot or might I have wired in something wrong?

Could be that you have a linear rather than an audio taper pot.  From a human perspective, a linear pot will tend to sound like all the real change in volume is at the first few degrees of the pot's rotation. 

Or it could be broke.

Other way around.
Audio taper pots go through 50% of their resistance range in the last fifth or so of their rotation. Linear tapers spread the range out, so the worst case scenario would be that you would have to roll the pot way down to hear a change in volume.

It's possible that the OP got a bad taper. Commercially available audio taper pots usually don't follow a true logarithmic curve, but rather, are made up of two linear sections that approximate a logarithmic curve. This is done in an effort to keep manufacturing costs low.

 

[bagman67]

Hmm... I reckon my very cursory internet research may very well have missed the correct way of expressing that.  What Line6Man said, I guess. Anyway, maybe you have the one you're not supposed to have, whichever one that is.

Heh.

Bagman

 

[stomp]

Well, I have the 500k pot Warmoth sells, which is labeled as audio taper. That said, I don't really notice the same effect on my tone knob, which is the same (with the addition of a cap).

 

[AutoBat]

After playing a friend's Ibanez earlier this week, I've decided that I'm going to change the pots in my strat.
The 1Meg pots that came with the vintage noiseless pups are garbage.  I had fooled myself into getting used to their odd usage, but after using ones that work so well & fluid it it time.
Now I need a quality 500k volume pot.  I'll leave the tone pots in place but disconnect them.  I never ever use them, but it would look wrong without them being there.

 

[line6man]

After playing a friend's Ibanez earlier this week, I've decided that I'm going to change the pots in my strat.
The 1Meg pots that came with the vintage noiseless pups are garbage.  I had fooled myself into getting used to their odd usage, but after using ones that work so well & fluid it it time.
Now I need a quality 500k volume pot.  I'll leave the tone pots in place but disconnect them.  I never ever use them, but it would look wrong without them being there.

The problem with 1M pots is that their resistance range is usually too high for the output impedance of the pickups, so they give you a poor control.
As volumes, they can be used in applications where multiple volume pots are parallel, which decreases the total resistance parallel to the signal, but even then, there is a lot of resistance in series with the signal when you start to roll one down. 1M pots should NEVER be used as tone controls, btw. Regardless of taper, you will not reach a reasonable resistance relative to the signal's impedance until WAY far down the rotation, so they will act like on/off switches.

If you like the effects of minimal resistive loading on the pickups, a single 500k volume usually works pretty well, but you could add a switch to bypass the volume pot when you want an infinite impedance load from the controls on the pickups.

Also, while this approach seems uncommon for guitars, you can try buffering the pickups before reaching the controls. This allows the pickups to see a constant impedance from the buffer, while volume is controlled at the low-impedance output. An added benefit is that the parasitic capacitance of your guitar cable has much less of an effect on the signal, further preserving treble content.
Make sure to buffer after the pickup selection, however, as individually buffering each pickup would not allow the LCR of the coils to interact the same way it would passively. 

 

[Strat Avenger]

I have a 1Meg ohm volume pot on one of my guitars (with humbuckers) and it works great with no issues of any kind. 
All my others are 500k. I had a linear taper volume pot once, and I hated it because I could not do volume swells. As soon as it came off of "zero", it was instantly 'on' -- no swell.  I use nothing but audio taper pots.