A review Bound for Sound for Pass Labs fans


I take all reviews with a "grain of salt" perspective. After all, their just someone's hopefully honest and somewhat informed opinion regarding the sonics of that piece in their system. However, I cut Martin G. DeWulf, publisher/reviewer of Bound for Sound, a little more slack then most for at least two reasons. 1) He has no ads so he does not have to "suck up" to any manufacturers for $. 2) He often prints negative reviews, if that's what he hears.

In the most recent Bound for Sound, DeWulf reviews the Pass LabsX-350.5, the first "professional" review that I'm aware of, regarding any of the .5 amps.

He states the following:

1) He thought that in the past that the X-250 was a great piece, but did not care for the performance of the X-350. DeWulf gives great credit to Pass Labs for not getting defensive regarding his past review that was negative towards the X-350 and being more then happy/fearless in sending him the new X-350.5. for review, he believes many other companies would not, if they recieve a negative review from him in the past.

2) He states that even with all the "Buzz" regarding the new digital amps, class D amps, class LMNOP amps, when people come over to hear his system, they all first get caught up in the "eye-candy" regarding the X-350.5, and then respond with, "That thing sounds awesome!"

3) He goes into great details regarding the build quality and new design changes that filtered down from the XA amps into the new .5 series.

4) DeWulf has auditioned many highly regarded Solid State amps such Ayre, Edge, Parasound, PBN Sierra Olympus and does a fine job of comparing the 350.5's sonics to these other reference single chassis or mono-blocks.

5)His final verdict regarding the 350.5's place in the hierarchy of world class solid state amps, "This is the finest solid state power amplifier that I've had in the Big Rig to date-long live the new king.

Well, I'm a big fan of Nelson Pass and the other guys at Pass Labs, I had the 350.5 as my reference (did a review of it here on the GON) only to be replaced by XA-100's, and am glad that this amp finally got the credit it deserves in a well done and through review.
teajay
Yes thank you, I've got it now. This is interesting because in the past, the original X.1000 was not deemed to be the best of the old series by any stretch. But the X1000.5 is the very latest of the lot, so it will likely incorporate the learning curve from all previous models/efforts. Thanks again. Guido
Gandme and Guidocorona, when I was communicating with Peter at Pass Labs at great length regarding if the XA amps, which did replace my 350.5, could power my MG-20r's in by-amped mode, one item that was clearly covered was that the overall sonic signature of the monoblock XA series amps does not qualitatively change, only the power/watts ratings.

This was very important, in that I noticed that the 350.5 at my loudest listening levels almost never left their Class A rating, which is around 50 to 60 watts. Therefore, it was decided that the XA-100's could drive my rig without distortion or compression. Otherwise, it would be on to the XA-160's at a cost of another $5000.00. Well, I'm no cheap skate and would have bite the financial bullet if I had to, in order to get the extra power if I needed it.

Well, I did not need the extra 60 watts of single ended Class A watts, to have the magic of the XA series in my listening room. But the major point regarding the three top XA models, 100's, 160's, and 200's is that their overall sonic signature is the same throughtout these monoblocks, the difference is their ultimate power ratings.
Gandme,
Yes this may be true with the XA and .5 series but not with the X series. I think you might find more people preferred the X250 to the X350. This may also apply with the X600 compared to the X1000.
TeaJay, did the friendly crowd at Pass indicate to you if any member of the XA family could power the MG20R speaker by themselves comfortably, or if a byamping configuration is always recommended when applying XA amps to Maggies?
Guidocorona, the opinion was that if you were going to run MG-20's or 20.1's with their passive crossover and not bi-amp you would have to go up to the XA-200's. However, Peter believed that a pair of 600.5's might sound better because of the loading of the speaker, but no one I know has run the experiement comparing a pair of XA-200's to a pair of 600.5's on either MG-20's or 20.1's run in a passive mode.

I think its apparent that I believe the 350.5 is just a wonderful sounding amp, if I was not a nutty audiophile/music lover looking for that last bit of "magic" I could have lived with the 350.5 for a very long and happy time. However, the XA-100's are the most beautiful sounding amps I have ever had in my system.