Hi Eljaro
I have tried many amplifiers with the Avantgarde speakers over the years.
Single ended triode I have tried 45, 2A3, 300B, 211, 845,6C33C,833A.
Push Pull EL34, KT 88.
My favorite is the 6C33C valve on the Avantgarde`s all round for top to bottom control/dynamics and inner resolution.
For some music (female vocals, strings) the 45 valve is incredible if the volume levels are kept to normal listening levels.
Push pull KT 88 is very good on the Avantgarde speakers, the Quicksilver Triode Mono block amplifiers, very quiet and dynamic & highly recommended on the Duo Omega speakers.
Solid state the Pass Labs XA30.5 is incredible all round amplifier on the Avantgardes Duo Omega speakers.
Thanks
Jason.