The Gaku-On amps that I am familiar with are from Audionote (uk) and employ 211 tubes in a parallel single-ended configuration (two output tubes per channel). A local dealer had a pair, and, I believe, one customer owned something like three pairs (two in operation as part of a triamped system) and a third as a spare. These were crazy expensive amps ($250,000 a pair retail). This amp sounds very good, but I actually personally preferred the sound of the Audionote Sogon, which cost about half the price; it has a leaner sound, but a more open top end.
