Not trying to be a d**k but how does the Moscode resemble the original OTL? It has a SS output stage (not that that makes it non-OTL like). Which OTL, futterman or circlotron?
Two reasons:
1. George Kaye intentionally aimed for an OTL like sound as a result of his experience working with the Jules Futterman design at New York Audio Labs(NYAL).
2. The amp is transformerless - the triode driver stage is dc-coupled to the speaker load through the output devices so they actively respond to the varying speaker load.
Now, I'm not saying that the Moscode qualifes as a traditional OTL amplifier (much like Berning's amps don't), but that it does share more similarities and goals with that design than the Butler.
To quote the Moscode website:
The challenge for me has always been delivering the tube refinement and sonics of the Futterman OTLs while using efficient solid-state output devices that can handle the heft and control in the bottom end. In a word, I have always wanted to combine the best of tubes with the best of solid state perfecting the union to bring about an unparalleled amplifier. BK Butler's Tube Driver BLUE technology places the triodes exactly where they should be: DC coupled through the output power devices to the speakers. Therefore, the tubes are positioned to naturally and actively respond to the dynamic speaker load. This also completely eliminates one of the most inefficient and non-musical components in a typical tube power amplifier: the Output Transformer. Without the phase shift and induction generation caused by hundreds of turns of wire and massive core iron to overcome, BK Butler's newly patented current multiplying DC coupled circuitry allows the 6SL7GT output driver tubes to directly operate into the constant ratio-reduced speaker load. This novel design allows the tubes to safely produce authentic power vacuum tube dynamic characteristics hundreds of times greater than their original design capabilities.IMO, your best bet is to do a home audition of both, since how each functions in your system will be unique.
If only that was financially possible. I've still got to pay for the custom corner horns to be made along with the rare drivers. I also need to try an active preamp(or two) to compare with my S&B TVC and both amp(s). I could swing a used preamp and Butler, but not either with the Moscode.
"So much to do, so little money"
