I have headed down that path myself. I have used some calculators based on a generic 15" parts express woofer I have lying around and 15 watts to show that it would output about 94db at 3 meters distance...would that be viable? Curious where this might lead, there is just something alluring about an entire 2A3/DHT system.
Tim
Unless you are doing this outdoors (big party?) it's the 1-meter equivalent that is most relevant. That would be about 104dB at 1 meter, or in the reverberant field throughout a typical listening room. Compare with PB's 98dB speakers and 8-watt Paramount = 107dB. PB is way younger than me; if you like me like your music a hair less loud then the 15 watts might just be adequate. If needed, make two subs and stack them!
Stereomour could be modified to a push-pull which would do close to 15 watts on momentary (musical) transients. This would however require a push-pull output transformer capable of 15 watts and with a 3000 ohm CT primary. Those are few and far between; you may have to go for a 50-watt transformer or greater to get there. Selecting one with good deep bass performance means a lot of iron and copper (5 to 10 pounds I'd guess). There's no way to fit it on the Stereomour chassis.
Hmmm.... what might work would be to use the Paramount iron with the two output transformers in parallel as a parafeed output, keeping the Paramount plate chokes. At this point, the total deviation from designs that have been tried is substantial, which makes the engineer in me nervous.
I'm pretty sure I would not like it for fullrange use. The crossover distortion in this nearly-class-B operation would be significant, and I don't really like the even-harmonic cancellation of push-pull either. But it might be acceptable as a sub amp, in a frequency region where the ear is less critical.
You may have noticed that this scenario is not exactly dumpster-diver cheap!
