I have been using the Pass Labs XA30.8 as my reference amp for the last 14 months. When it came in for review, I was shocked at how good it was. After an agonizing audition period, I decided it had dethroned my $30,000 Wavac EC300B with Western Electric 300B tubes. The Wavac had held off all comers in my reference system since 2007; truth is I thought it was probably the best amp around at any price if you could get by with eight watts. So, the only question left was how would the mono-block version the XA30.8 sound?
At a quick glance, it seems that the XA60.8s are just two XA30.8s wired for mono instead of stereo. They are rated at 60 watts pure Class A into eight ohms and 120 watts pure Class A into four ohms. The XA60.8 doesn’t leave pure Class A until it reaches 122 peak watts. Then it moves into Class AB for unheard of headroom for a 60-watt amp. Since I have never been able to get the XA30.8 out of their Class A biasing range, it should be no surprise that it didn’t happen with the XA60.8s either.