pass labs xa30.5 vs aleph 3

I had a chance to A/B the XA30.5 vs the Atma-Sphere (A-S) M-60Mk3.0 (with stock driver tubes - not the NOS which are recommended for top performance) on my Geddes Abbey speakers.

The Abbey's are a large sealed box 2 way monitor with a compression driver mated to a 12" waveguide and a 12" pro woofer and roll off at 50Hz 12db/octave. I use servo subs for the LF. They are 95db efficient, 8 ohm nominal and have a reasonably flat impedance curve which has a dip to 5.5ohms. According to Ralph Karsten and Duke who saw the impedance curve, they are well suited for the A-S.

My source is a Zalman silent music server with a Lynx AES/16 card driving a Berkeley Alpha DAC which has a built in pre-amp section with XLR and RCA outputs. I drove both the XA30.5 and M-60 with balanced outs.

The superiority of the A-S was evident within seconds. It was not a subtle difference. My wife, who is the ultimate anti-audiophile, for the first time ever asked me why the system sounded so much better and sat down to listen to some tunes.

I observed the same thing as Madfloyd. While I regard the XA30.5 as the best SS amp I've heard in recent memory, it doesn't come anywhere close to the A-S in terms of transparency, dynamics, tonal texture/shading, soundstage depth/width. I never thought a 2 channel system could get this close to sounding live. The realism of the musical presentation was magical.

In terms of power, I only have half the power tubes in my M-60's presently and they had no problem blowing me out of the room. Of course as Tvad has noted, this is very speaker dependent and YMMV. I'm going to get my M-60's upgraded to Mk3.1 level and buy some NOS driver tubes.

Glad things worked out for you Earflappin.

George

Yes, like Earflappin, I too did the XA30.5 versus Atma-sphere M60 "test", in my case with the Merlin VSM-MXe. There is no doubt that the Pass are the best SS amps (Aleph, Aleph J, and XA30.5) I have heard, yet it was not a difficult decision to choose the Atma-spheres. My feeling is that when an OTL can match up with a speaker, it is a pretty difficult combination to beat. There are maintenance issues involved with using tube amps, but there is something to the sound of tubes that I feel makes it all worthwhile. As to OP, I think that is very possible that the Aleph J (better than the original)with tube friendly speakers (highish, smooth impedance)might be every bit as good as the XA30.5; proabably becasue it is a simpler circuit with fewer parts since it is not trying to deliver more current with dipping speaker impedances.

George, my thanks to you for sharing your experience with the A-S amps, as well as to Pubul57. I had to buy the M-60 without having heard it and the conversations with you guys gave me the confidence to take that risk.

I would agree with Pubul57's conjecture about the Aleph J vs the XA30.5. Also, First Watt has come out with a new J2 amp that should sound really good as well, but the output power is fairly low.

As soon as someone has heard the J2, let us know you impressions. Sound intriguing, but it is only 25 watts, proabably 90db or higher sensitivity.