This system sound very musical.
The most notable thing is the cost of amplifiers is modest compared with that of speaker.
Raidaho speaker cost 70k$ while Margules power amp and pre amp cost 10k$ and 7k$ only.
I got the feeling that Margules pre is good.
Thus I bought it at show discount price of 6k$.
After installing in my system, I am happy with it.
It use 4 12AU7(ECC82) and one 6922(6jd8) tubes.
Thus lot of room for tube rolling.
I replaced the stock Elextro harmonic tubes with NOS Amperex.
It really sound gracious.