pot measurement

[trem]

With the amp Off and the power cord Unplugged, a volume pot should always measure 1M shouldn't it.?
Mine is (round numbers) 150k.
It is 150k when:
I measure across the pot.
From wiper to end it sweeps from 2 Ohms to 150k Ohms.
From chassis ground to pot end is 150k.
Is something wrong.?
This is basically a Fender Princeton tone stack.
Instead of a 250 pF i have 120.
My mid cap from bass pot to ground is 9k1, but all other values follow this schem.
Thank You

http://el34world.com/charts/Schemati..._sf_aa1164.pdf

[Enzo]

Nope.

Remember, EVERY part in this thing is part of a CIRCUIT. Nothing stands alone, unless it is a loose part in your drawer.

Look just left of the volume pot, what do you see there in parallel with it? I see two pots and a resistor. Or three pots if you made the mids resistor a pot. Turn the tone controls all to zero, I'll bet your volume pot now reads more like 8k. Turn the treble pot up and down, or the bass pot, and watch the volume control reading change too.

Does the amp make sound? Does the volume pot control the volume of the sound? Then the volume pot is working. Even a bad pot doesn;t usually change value. Mostly when they fail, they go open, get noisy or intermittent.

[trem]

Right...they ARE grounded on one end and then share the Treble Wiper on the other end.
Yes, the volume pot does work. I did turn the Bass/Treble pots, but i do not think there was any change. I will check that gain.
Thanks
yes...the T & B pots react with the V pot as you say.

Let me ask this, is it "normal" to lose a lot of gain across that first (120 in my amp) 250 pF coupling cap.?
With 3 Volts coming off of the fist triode, it drops down to 0.50 Volts after that first cap. There is almost nothing coming out of the volume pot.
This is with 1kHz, 200mV going in, and the volume pot turned down pretty far, but definitely not Off.

[Enzo]

The Fender tone stack is indeed a large loss of level.

Only the treble comes through that cap.

[Enzo]

The Fender tone stack is indeed a large loss of level.

Only the treble comes through that cap.

[trem]

Right...OK...so the loss has to be made up again in the gain stage after the tone stack.
Thanks Enzo
All this came up as i tried my first digital scope...trying to find "noise" that was not there after i built this the first time....about a year ago
The noise is effected by the volume pot, so i was sticking the scope around before that point and was wondering about what i saw. I have changed tubes but that is not the problem.
I am out in a shed in my backyard...so i probably need to bring this amp inside, i have clean power (a dedicated circuit anyway) in my living room.
My Amprobe DMM has a Hz setting on it. If i disconnect the 1kHz signal, and just let the In Jacks short, can i stick my DMM across my speaker jack and measure the "noise".? I will give that a try now.
My meter does not pick up much. It kind of jumps all over the place. It goes from Zero to bigger with the Volume knob, but is not steady at all. I thought that, with a dummy load, i could maybe see the Frequency of the noise.
Thank You