With the use of more effecient speakers lately, I have been able to pull out some 300B amplifiers that have been sitting in their boxes since they arrived.
This first picture is of a pair of Ming-Da push-pull 300B mono blocs producing 25 watts using a quad of EH300B tubes. The sound of these amps is noticably different from a single tube SET design (as shown in the second picture). There is a fullness in the lower end that is not experienced with a true SET design. They do sound very good at this time driving the Bella speakers even with just a few hours on them. I can see where some tweaking will be required. After they fully break in I will spend some time doing serious listening, then they will get "the treatment"
Sometime next week, they will be driving a pair of Usher D2 horn (TAD 4001) based speakers being driven by a ModWright SWL 9.0 preamp.
The amps below are some of my early Musica Bella units. These are 8 watt units also using EH300B tubes. The Piano Black units are the Reference versions with the satin stainless steel versions used for prototyping circuit changes. Before you ask, yes these are Ming-Da chassis but that's it. The transformers now used in these amps are Hammond units and the circuit is my design. Capacitors are currently Audio Note copper PIO which will soon be torn out in favor of V-Cap Teflons and OIMPs. These have been used for some time driving various speakers including the Daedalus DA-1 as well as our Musica Bella SP/AV-1.
Gotta love those 300Bs
