18w TMB PrePI Master Resistance Value

[bgkyt1]

Hi all.
Should an 18w TMB style amp with a 1M Master measure close to 1M resistance on pins 1-3, while in the circuit?
I see where the TMB pots affect the resistance of the master, since they are feeding it,
but should the outside pins always measure around 1M?

I only get around 500k no matter what. (all other pots dimed)

Thanks...

[Ten Over]

Hi all.
Should an 18w TMB style amp with a 1M Master measure close to 1M resistance on pins 1-3, while in the circuit?
I see where the TMB pots affect the resistance of the master, since they are feeding it,
but should the outside pins always measure around 1M?

I only get around 500k no matter what. (all other pots dimed)

Thanks...

No. The tone pots are in parallel with the 1M MV for DC purposes.

What are the values of the tone pots?

[bgkyt1]

Thanks.
Pots are:
T=250
M=25
B=1M

[bgkyt1]

No. The tone pots are in parallel with the 1M MV for DC purposes.

What are the values of the tone pots?

Thanks Ten Over for your reply.

The reason I wondered about the pots was
that I had the amp built new in 2009,
lent it to a friend in 2011 and haven't heard the amp since.
It was stored in a damp out-building since then
and has visible rust and corrosion.

It's been a long time since I played the amp,
and I'm used to other amps since then,
but the amp sounds dark (not enough hi end)
and the overdrive doesn't sound as good as I remember. (now more like power section hard clipping, not smooth preamp clipping)

I tried different power tubes and a different 12AX7 in v1 and v2, with no difference. (haven't tried v3).

It could be that I just haven't heard the amp in a long time and it always sounded dark.

[Ten Over]

Thanks.
Pots are:
T=250
M=25
B=1M

In an ideal world, you would have 1.275M in parallel with 1M for a total DC resistance of 560k.

[bgkyt1]

In an ideal world, you would have 1.275M in parallel with 1M for a total DC resistance of 560k.

Thank you for the info!