Help, please...Volume rolls of too quickly

I would wait for at least a second opinion on this, but it sounds like you might have linear taper pots rather than audio taper pots. Linear taper pots bleed the signal to ground based on a linear ratio and don't sound right to us because we hear volume in a logarithmic ratio.

Linear pots will feel like they have all the change bunched up at one end, though I've more often heard of the problem being the reverse of what you have -- that is, the pot does nothing until you get down to about 3, and then all the drop off happens. So I'm not completely sure that your problem is that the pots are linear. However, components such as pots are mass-produced, so even if you bought ones that were marked "audio taper" they may be linear because a batch got mixed up.

That's my best guess, but I'd wait for others to chime in before you give up on the pots you've got.

 

i agree....

 

You can, of course, test the pot's taper with a multimeter. Set the pot to a mid-way setting, and test DC resistance from the input lug to each of the other lugs. If the values are anywhere close to equal it's linear, otherwise it's audio. You may need to disconnect the pot before you test it, though.

 

Maybe you got a lefty pot?

 

So the problem is the resistance gets high to quickly. I wonder if you could tweak that by putting a 1meg resistor in parallel? I don't know I'm just speculating.

 

I don't think there's any such thing as a reverse linear pot. Linear is linear, if you know what I mean. There is a big difference, however, between an audio pot and a reverse audio pot, but I think reverse audio is highly unlikely.

By the way, my instructions for measuring the side of the pot earlier were rubbish. Center the pot along its rotation and then test resistance from leftmost lug to center. Then test from rightmost lug to center. Linear pots should show both sides as equal. Audio, one side should be 10-30% the other side should be 70-90%. Good luck.

 

I love it . As difficult as it is finding leftie pots , I would doubt that you would get one by mistake . Never know though .

 

Is it possible it is a 1 meg pot, mislabeled? 1 megs with single coils will function almost like an on/off switch if they don't have a treble bleed cap or a bleed cap and resistor wired in the circuit.

 

An audio pot, A250k, is the one that bleeds off the sound too quickly, at half way you are down to 1/10 the signal voltage - you want linear volume pots B250k, they allow you to bleed off treble without losing much volume until about a third of the way down. The Linear pot allows fine control of the volume.

A250k is for the tone control.

 

This is true of voltage, but not of volume the way the human ear hears it. Linear taper is actually perceived as a hump, and a linear pot would function more like an on/off switch, with most of the volume coming in the earliest part of the rotation.

 

I agree and I agree. In my limited experience with treble bleed kits I have found that both a cap and a resistor in parallel wil not only retain your highs but also change/smooth the taper of the pot.