Some reviews say that you need to have very efficient speakers, but it can easily drive most of the speakers

so you need normal speakers , you do NOT need especially sensitive speakers

You need efficient full range speakers (90db+ & 34hz-20khz)

All in all the sound on these amps is rich and full, even with a somewhat limited speaker pairing

With more sensitive speakers like my Fostex it'll obviously scream

The amp is not perfect and you will need pretty efficient speakers but there is not much of a gamble at the price

RB-61 ii speakers (very efficient so they go well with this amp) and never looked back.

if all you listen to is chamber music through 100db sensitive speakers you will occasionally notice it during music

I have it connected to Paradigm Prestige 75F (great speakers) that are 92dB sensitivity and rarely go over 11 O'clock on the volume dial

For some reason, my classical radio station seem to have more energy directed to the left side as far as stereo is concerned (just hear the left speaker so as to sound like a mono recording) so I need to be able to make the right speaker louder to compensate for this effect.

Blows away the Logan motions my monitor audio towers and both my psb pairs in emotional 'music' conveyance while not being too concerned as a speaker with some of the finer points of articulation and soundstage treble extension or , especially , bass

Needs efficient speakers

The build was very good and at this price it is a no brainer if your speakers are sensitive enough for the low power output

These tubes definitely improved the sound, but not sure I would recommend as they were pretty $$$.