I run Sonic Frontiers SFM-160s, which use four KT-88/6550s per amp to produce 160w. My current situation has Gold Lions in the amps. Great sound.
I exchanged e-mails with Chris Johnson re: the KT-120s. While an increase in power of about 10% is common in SF gear (which of course was not designed to take full advantage of the KT-120s), Chris felt the major benefit in his equipment was the LT reliability. The SFM-160s really push the four KT-88s hard and I do have tubes go a bit more often than I would like. With the KT-120s, the LT reliability issue is much better.
I have not tried this, as I recently re-tubed with matched quads of Gold Lions. Plus, I am very happy with the sound.
I exchanged e-mails with Chris Johnson re: the KT-120s. While an increase in power of about 10% is common in SF gear (which of course was not designed to take full advantage of the KT-120s), Chris felt the major benefit in his equipment was the LT reliability. The SFM-160s really push the four KT-88s hard and I do have tubes go a bit more often than I would like. With the KT-120s, the LT reliability issue is much better.
I have not tried this, as I recently re-tubed with matched quads of Gold Lions. Plus, I am very happy with the sound.