pass labs xa30.5 vs aleph 3

I think Madfloyd already summed up a lot of my thoughts on the sound differences between the XA30.5 and MA-1's, so there really isn't much more for me to add on that front. Simply put, the system lost a good deal of its "magic" when the MA-1's were taken out and replaced by the XA30.5. For the majority of my listening, I didn't see the meter move on the XA30.5, so I don't think it was running out of gas or being pushed out of Class A mode. As such, I don't think it was an "unfair" comparison with the MA-1's.

While Tvad is certainly entitled to his opinion (and I do respect his opinion) I am in full agreement with Madfloyd in
that we both heard so much of the Pass sound of his XA100.5's when the XA30.5 was put into my system. While Madfloyd would have no issue with bringing his amps over to my place, I did indeed tell him that I didn't think it was necessary. Maybe one day I will take him up on the offer, but for now my curiosity has been satisfied.

Getting back the to the Atma-Sphere amps...I don't think the improvement of the MA-1's over the M-60's is so much about the extra watts, as it is about the ability to work better with a 4 ohm load. With the M-60's, I felt that I had to use the Speltz Autoformers with the 5A's to sound their best, while the MA-1's didn't require them.

I plan on talking to Ralph next week about upgrading my MA-1's to Mk 3.1 status (from Mk 3) and will ask him his thoughts on this subject.

George

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.