info on Kaneda DC amplifiers

Recent Kaneda style amplifier is based on 2 stage differential, followed by collector (or drain) follower SEPP. Because it uses same polarity output devices instead of complementary polarity output device in SEPP output stage, it is called Pure-Symmetric Amplifier. Both pre- and power- amplifiers are based on similar topology.
There are quite a number of variations in this topology, some uses vacuum tubes (triode in pre, and pentode in power), others use J-FETs (2SK246 in pre, 2SK117 w/2SC1775A cascade in power)for input differential circuit. Recent pre uses triode-connected WE717, WE403B or WE398 for first differential stage, and WE404 or WE435 is used for power.
One of the advantage of this topology is that it does not use P-ch FET or PNP for output stage, thus, N-ch which does not have complementary pair or tubes like 6C33, 5998A can be used for the output stage in exact same topology.
First stage uses constant current source circuit using 2SC1775A or 2SD756A.
2nd differential stage consists of 2SJ103 or 2SA606 or 2SA1967 for hybrid pre, and its load register is connected to base (or gate) of the output stage. The other terminal of the load register is connected to emitter (or source) of output stage. Thus, each side of SEPP output stage operates in collector (or drain) follower.
One significant property of his design is relatively high NFB rate, over 40dB in most of his article, which is much higher than most of DIY ones.
Among almost 200 articles Dr. Kaneda worte, the most popular circuit in Japan might be flat amplifier part of #168, which consist of 2SC1775A(ccs)-2SK246(1st Diff)-2SJ103(2nd Diff)-2SC959 (SEPP). I am using 2SC984(ccs)-2SK246-2SJ103-2SC1775A(SEPP) version in my D/A converter, and I love its sound.