Is a Bryston 3B SST2 enough for Magnepan 3.7i or 20.7?

Anthem's PVA 2 is comparable to the Bryston, but still not really what you want to run the Maggies.  I would say step up to Anthem's MCA225 $1999 Retail 225w x 2.  More power and more open sounding than comparable Bryston's.  Bigger money - go to the Anthem P2 $4500 325w x 2.  

OK, I’ve read this thread and here are my thoughts, simple as they may be. A 100W capable amp and a 200W capable amp will output the same amount of bass at the same wattage. Notice I have used the word "capable," as it is the "maximum" wattage the amp is claimed to produce. If each amp is putting out 25W at a particular point, then the bass output would be the same.

Now, the capability issue comes into play generally with musical peaks, and/or low sensitivity or low impedance speakers ... it is in this area where wattage capability becomes important. A 200W amp will better address those issues than a 100W amp, and will provide more headroom when and if needed. Is a 200W amp preferable to a 100W amp? It depends on several factors. However, if one listens at low levels mostly, then the difference in wattage becomes somewhat negligible.

Nonetheless, I agree with both propositions that: (a) amps outputting the same amount of wattage at a given point in time will output the same amount of bass; and (b) a larger, more powerful amp generally will provide better control of a speaker IF the additional wattage is necessary for musical peaks (i.e., high volume listening), a speaker with low sensitivity, or a speaker which is not stable into a relatively normal impedance (i.e., 8 Ohms). Them’s my thoughts, no flaming, please.

rlb61,

I agree with all you have said in your post.  I am currently waiting to get the funds together to make the 3.7i purchase.   I'll le you all know how it turns out.

GK

Here are my two cents as a longtime Magnepan owner (SMGa, 2.7, MG.6, MG-12, currently 3.5s). I like to crank it up and have my Maggies in a pretty large room (about 4000 cubic feet). Power makes a big different in that situation. When I had my Sunfire amp rebuilt recently (600wx2 into the Maggies), I used a Shiit Vidar to fill in during the repairs (Vidar does 200wx2 into the Maggies). The Vidar worked wonderfully, excepting lacking dynamics when cranked up. At lower levels there was no real difference aside from the voicing of the amplifiers.

For your situation, enjoy the 3BSST2. Its 250 watts into 4 ohms should be plenty for your listening preferences. For my situation, I would want more power, but even using a 14BSST would only give about 4-5 db headroom over your 3BSST2.