Pass XA30.5 vs. ARC Ref 75

Has anyone compared these two particular amps? I own the Pass, and I'm thinking of test driving the ARC (a.k.a. buying it on Audiogon, and selling if I don't prefer it to the Pass).
I own both amps. I have had the Pass XA30.5 for about 4 years and have been very happy with it. It's performance has been excellent driving my Focal 1028Be speakers via an ARC LS27 preamp, DAC8, PH6 and WTL Versalex turntable.

However, the ARC Ref 75 is simply a more soulful sounding amp. It offers a bigger deeper soundstage, richer tone, great dynamics, natural detail, and a generally more relaxed and realistic presentation. Some things tubes just do better than anything else. And remember, I like the Pass and have enjoyed my time with it. But the Ref 75 has that special Magic. In general the Ref 75 reviews I have read online were accurate and said basically the same thing.
It would ultimately depend on your listening preference and how each amp pairs with your speakers. Even though I'm a huge fan of Pass and Pass Class A in particular, I would suggest giving the REF75 a go for sure. If forced to pick between these two amps, I would pick the REF 75.
Amplifier magnifies electrical signal to drive speakers. If one goes by straight scientific terms, it just increases the voltage and current of the signal, adding nothing and losing nothing. In fact it is not difficult to have am amplifier to do just that. But the sound would tend to be plain and harsh.

Music makes up of harmonics. Without it, music is just any sound, no soul and feelings. Some amps are better in keeping and enhancing the harmonics. They sound better, more involving and satisfying. It is the strong area of a tube amp and this is Pass Labs just cannot give.
No vs 2 good amps that sound completely different both great.
I've not heard the 30.5, but used the old Aleph 3 for a good few years and loved it. It was certainly one of the best amps I have owned. I currently own the ARC Ref 75 and I concur with everything Esharp says. An accurate, detailed and dynamic amp, but with a rich, full sound, that doesn't compromise that neutrality. I have compared it with it's more powerful ARC reference brethren and I actually prefer it.

I am not a fan of magazine reviewers, but a very experienced UK reviewer who has used ARC for years and bought the 75, commented that he felt that 50 to 100 watts was often the sweet spot in the ARC Power Amp range and he preferred the 75 to the more expensive 110 and 150 amps. I know there are better amps out there, some like Dartzeel and D'Agostino momentum amps, that I have heard myself. You are going to pay multiples more to improve on the 75 though, in my opinion.