Master Volume Troubles

[hesamadman]

I'm having a slight issue with my MV. I may know the cause but I am out of town for the weekend so I thought I'd get a opinion before I make the change. I have the ac30 power amp with a custom preamp. Two 12ax7's with a cathode follower 2204 tone stack. Same PI that's in the ac30. My master volume follows directly after the treble control pre phase inverter

The problem I am having is this. I have to turn the MV 7
up to about between 1 and 2 ("these amps go to 11") before I get a usable tone. There is no playing this at a low volume, unless you want a fuzzy sound with all highs and no lows. But hey that's not a huge deal really. The main problem I am noticing is once it gets a little past 2. Maybe 3 or 3.5 area it's full volume (I'm assuming it's full. It's loud) and anything after that setting doesn't seem to age t the volume at all. So it maxes out at about 4. These numbers are not o'clock. The number settings on the face plate. Anyway it's a 500k pot. I did have a 1m that was the same way. Changed to a 500k to try it.

But maybe this is part of the problem. There is a 220k resistor that follows the MV into a .047 CC. Maybe removing this 220k will help? I don't even know why it's there anyway. I must have made a mistake when laying out the amp.

[sluckey]

Sounds like you used a linear taper pot. You need a log (audio) taper.

[hesamadman]

I originally thought that same thing. I checked the packaging it said audio. But maybe they packaged it wrong.

[Willabe]

Check it with a meter. If it's a linear pot, that 500K pot will be about ~250K at the half way point.