Hi Batt, I have pp 2a3 mono blocks, and 300b sets consisting of a pair of mono block "legacy" 300b amps (sv83 driver) and a stereo chassis WE91a knock off using 6sj7 driver with regulated screens and about 3db plate to plate feedback. The 2a3 amp is a bit more over the top. All the signal iron (input/splitter, interstage, and output) is Lundahl AM cores, the PT is a Lundahl unit with two 250 volt secondaries in parallel for 860 ma capacity, a hybrid bridge using a pair of damper diodes into a cap input filter using a low dcr Lundahl choke. The driver stage uses the same 250 volt windings feeding a choke input 5ar4/vr150 setup feeding a pp input stage (5687 running about 18-20 ma per section), input transformer phase splitter, pp interstage tranny feeding 2a3 grids. The 300 b amps are pretty well done, but not to the same extent. The "legacy" amps each use an Angela universal pt, good for 380-0-380 at 250ma, 5u4gb rectifier, a 10hy 200ma choke with small c / L / big c filter to output, with additional 5hy choke and cap filter for input. Output is a Lundahl tranny. The WE91a knock offs use a Lundahl power transformer delivering 350v at somewhere around 450 ma (can't remember at the moment) into a snubber bridge/damper diode combo into a pseudo dual supply with each channel being fed by a separate 7hy 150 ma choke/cap combo. The driver stages share a common vr105 regulated screen supply. Output transformers are One Electron. Sonically, all are very good. The pp 2a3 offers more control of the bass, more detailed and dynamic overall. The SE amps are more lush in the middle, very easy to listen to! I use the 2a3 amps ( and occasionally the "legacy" amps) with a pair of GPA 604 and Altec 416 in a 2.5 way configuration in 10 cf boxes for home theatre and phono duty, while the 91a's drive a pair of MA 12p full rangers with subwoofers doing mostly tuner duty. It seems to me that well implemented pp will best SE, and vise versa.
