Recommend Class a Amp

Wow! Congratulations, John. I seem to recall that you were thinking of the Ulysses a while back. Hope you are enjoying them as much as I do mine!

And re the INT-30A, I **would** expect your experience with it to be likely to have relevance to the XA30.5, in contrast to what I said about the Aleph 5.

Best regards,
-- Al

Almarg, yes I know you are right when you said we should not lump the Aleph and XA.5 designs together. For that reason, I almost didn't comment at all on the post about the xa30.5. But I have heard too many commentaries from xa30.5 owners that sounded similar to my own experience with the A5 to ignore a conclusion. Even Pass factory folks themselves are aware of the pros and cons of both A and AB designs (hence the reason they offer 2 separate designs of course) and they are always interested in 2 things when you probe for recommendations, especially regarding their class A amps: what kind of music you will be listening to, and what speakers you will be driving.

I own B&W speakers that are not inefficient but which respond well to the grunt that the AB designs deliver. They specifically recommend the AB designs in my specific application over the class A models.

I own B&W speakers that are not inefficient but which respond well to the grunt that the AB designs deliver.

isn't this a contradictory statement (it sure looks like one to me)?
Since the passing of John Bowers himself in the mid-1980s I haven't seen a B&W that is efficient. Yeah, they have a 90dB or sometimes even a 92dB SPL number but they almost always (with rare exception) respond best to high current current amps.

it's interesting to see that Pass Labs recommends their class-A/class-AB design over their pure class-A design for B&W. I'll have to dig around a little to figure out why.....

Thanks Al!

I got lucky with a local enthusiast who is moving and needed to downsize. They are non-poly v. 1s, but so far feeling little pressure to consider updating them :) I may be picking your brain regards set-up, though i'm pretty happy with where I have them now.

Regards the present topic, 30w of Pass makes a nice match for these speakers, with a claimed sensitivity of 97 db or so, but I could also imagine greater ease at higher volumes with more grunt.

John

I own B&W speakers that are not inefficient but which respond well to the grunt that the AB designs deliver.

isn't this a contradictory statement (it sure looks like one to me)?

Hi Bombaywalla: not really the same thing. When I mentioned "not inefficient" I meant simply the Sensitivity rating of 90 spl is not considered low (or inefficient). It is fairly average (if there is such a thing). But this doesn't mean that the speakers don't work better with amps that can grip them and drive them the way the loudspeaker designers intended. It's not all about the Sensitivity and nominal impedance ratings. There is also something referred to Qts that plays a big part. I don't pretend to understand it myself; I am just pointing out that even the amplifier manufacturers recognize that the amp-loudspeaker relationship is complex and even they have some challenge explaining.