ShortScale.org

in short, im in love with my 68 drip edge ab165 circut bassman head and cap.
my question to you all.
what does a 71 of a different circut sound like?
whats the pro or con of the master volume?
whats the bassman ten sound like with 4x10 speakers/ whats the circut?
i know these are pretty random/ vague questions but i kinda want to know what the general idea of bassmans and years are, in terms of good, bad, pro and con.

Every bassman I have heard or played sounded great. The bassman 10's I think break up easier than a bassman head (but I only have a littel experience with the bassman 10's) The tweed bassmans (even the newer re-issues) are awesome as well. I know some of the later 70's bassmans are not as well regarded, but I think some of that was quality control and you can get by that just by playing them. Also, I think some of the 70's bassmans were 135 watts.. personally the bassman 50 or bassman 70 is better due to the lower wattage/easier breakup. Although I know little of the differences in the actual boards, etc.... I am pretty sure that as long as it is in good condition and you get a decent deal on it, any tube bassman will work out well for the most part..

The MV sounds pretty crappy in my opinion. I thought it made it really ratty (not in the ProCo way), but it could have been a shit amp too I was playing. It was at a local shop where they take in loads of 2nd hand gear (and don't tune stuff up before they sell).

I believe Chicago Mike's talking about the pull-boost feature they added to some Master Volume controls in the mid-70's. Pulling the MV knob out gave you this harsh, thin, ratty distortion that nobody much likes. But that's only if you pull the knob out. You can definitely use the MV in the normal way without engaging the pull-boost, and as far as I know the early-70's Bassmans (Bassmen?) did not have the pull-boost MV anyway. I removed the pull-boost circuitry from my Twin and figured out a pretty nice fat-boost trick that uses the stock push-pull switch on the MV pot. I'm not sure if you could do that with a non-reverb amp like a Bassman, but there may be something similar you can do.

As for the MV itself, I think they're useful. Set it at 10, and it's more or less the same as no MV. It does drain a tiny bit of signal to ground, and it may serve as a mild low-pass filter to some extent as you turn it down. Fender added a partial high-bypass circuit to some MV models to minimize the low-pass effect.