Metropoulos Forum

I've tried to search but the Lar-Mar thread is so long I can't really find a definitive answer.

I have only built one amp with a Lar-Mar master volume and used a dual Alpha pot I had. I found out that I actually liked the master volume a lot in that amp, so I'm thinking about adding it to one or two of my other builds for practical purposes. But I am wondering if it makes a significant difference to use PEC pots insted? I know George is a big fan of the PEC dual pots for his master volumes, but IIRC he is using a different type of PPI master volume, is that right? With the Lar-Mar, does it make any sense to buy the much more expensive PEC type? The rest of the pots in these particular amps are Alpha FWIW.

I will try a zero-loss FX loop in these same amps, but that shouldn't have a bearing on my choice, I would assume?

I doubt it's worth getting a PEC. I have an Alpha (or whatever Metro used to sell) that has worked fine for 11 years of regular use.

No difference in tone that I have been able to hear. The PEC pot does have a smoother taper, especially on the lower end of the range. Readings between both halves are also much closer on the PEC. Alphas can be quite a bit apart.

Thanks guys! I think for my uses (typically keeping it at around the halfway point or a little higher) the Alphas will do the job just fine.

I found a fair amount of variability in the Alphas at different knob settings (I had cause to experiment as I had one pot that was faulty and the MV did not work). As a consequence I have not been fitting PPIMVs recently (just using attenuators) but then most have been restorations as time permits.
Might have to try a PEC some time. CTS do a nice Clarostat type dual pot too.

some dual pots are too unbalanced/assymetric to be usable. One pot reads 220k, the other 270k and the taper also differs