Pcs,
I'll not add any to Sean's posts, he's got far more equipment experience than I do. I will comment on service; however. Remember that Threshold's last designs, the T series, used IGBT transistors that are no longer available. I don't know for sure, but I'd bet that the Forte amps all used bipolar transistors (Forte was manufactured at the same time as the Threshold S series amps I have).
There is an ex-Threshold technician named Jon Soderberg in California that services Threshold equipment. I'd seen at one time that he is willing to replace the T series IGBTs with another, readily available transistor. I have no idea what that would do to the sound on the amp.
I'll not add any to Sean's posts, he's got far more equipment experience than I do. I will comment on service; however. Remember that Threshold's last designs, the T series, used IGBT transistors that are no longer available. I don't know for sure, but I'd bet that the Forte amps all used bipolar transistors (Forte was manufactured at the same time as the Threshold S series amps I have).
There is an ex-Threshold technician named Jon Soderberg in California that services Threshold equipment. I'd seen at one time that he is willing to replace the T series IGBTs with another, readily available transistor. I have no idea what that would do to the sound on the amp.