I came across an unfinished project stashed in my basement a month or so ago and decided to bring it to some closure. Back in 2006 I built a PPP KT88 Eiclone amp that I named Ikezilla, and a couple of forum threads describe that prototype amp. My intent was to build a pair of those and I had almost everything I needed except a proper chassis and a few odds and ends.
So I threw them together using a couple of canary wood bases, 10"x12" top plates and some Hammond Iron. The OTs are 1650T and the PTs are 278Xs. That makes 21 pounds of iron per amp. The 1650Ts have an impedance of 1.9k, so hooked the binding post to the 4 ohm taps, and plan to use 8 ohm speakers and dummy test loads. This will give me effectively 3.8k.
I just finished wiring them yesterday and powered them up last night. Everything went well, my B+ is ~550 volts, and all the other voltages are within a few percent of my design values. I wired the boards so the voltage gain tube is an octal 6SL7 and the 6SN7 phase splitter cathode is current sourced.
Next step is to get the Boonton fired up and see what these will do. My plan is to bias the KT88s real hot. The target is 100 Watts at 1k <1%THD. I also want to get a quad of the new KT120s and see what they will do. There is enough capability in the 278X that you could bias the KT120s at 80-90 ma.
JT