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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
gandme
212 posts
 
I also thought the X-150 sounded better than the X-250.The X-350 runs in class A for the first 50 watts. At most listening levels I'm in class A with my 350. I believe the 250 is rated 25 or 30 watts class A. Chalk it up to equipment senergy and personal preference. I have not heard a bad sounding amp from Pass, but I have heard Pass Amps that sound unique in their own way. I'm surprised that there are so few Professional reviews out on Pass Labs equipment. The Aleph series seemed to get the most attention.
Teajay, I'm in total agreement with your opinion of the Pass Labs crew... outstanding!
muralman1
1,527 posts
 
Ozzy, check out my system. I ran the X-150 on 4 ohm speakers. When I got larger, less efficient 4 ohm speakers, the X-150 had no problem with those. The X-150 was running AB all the time.

In anticipation of getting my present speakers I upgraded to the X-600 amps, jumping over the 250 and 350. The 600 runs class A to 150 watts. The meter shows when it crosses into AB. It was warmer, and fuller than the X-150. Most of us liked the 600 better, but at least one favored the 150 on the 4 ohm speaker.

Then came the infamous amp eater. The powerful 600 stepped gracefully to the plate. I had no reason not to believe I was hearing the best.

On a report from another 1ohm speaker owner, I tried an ICE amp. The specs show the 600 a clear winner. S/N was 150 compared to 115. Power was 600 watts compared to 250 watts. Well, specs don't tell the whole truth.

With 93% efficiency, the ICE amp was actually in better control of 1 ohm. the ICE amp was far clearer too.

I sold that amp to a very happy deep pockets guy, whose awesome system is featured at Audiogon. Look for the third floor view.

Now, well just read my system review. There just is no looking back.
irish65
170 posts
 
From my limited experience I thought the X250 sounded better than the X350. When I contacted Pass in Oct. 2004, just before the release of the X350.5, Peter said the X350 was not their best sounding stereo amp. He also mentioned at this time that out of the new .5 series amps the X350.5 was at the top of the heap. He has it in his own setup in his home.
I did purchase the X350.5 after my conversation with Peter Perkins and would agree with what has already been said about this amp. I used it with Thiel CS2.4 and the X600 with Thiel CS 7.2. As an experiment I tried the X350.5 with the big Thiel's and preferred the X350.5 over the X600. The X350.5 gave up a little in the bottom end, and I say a little, over the X600. However, the midrange and top end with the X350.5 was clearly better. The music just flowed and the top end was silky smooth.
Regarding the X600.5 I would like to hear from others who have auditioned this amp.
Ag insider logo xs@2x
drubin
3,274 posts
 
Ah, thanks for setting the record straight. It was your post about this some long time ago that I mis-remembered.
guidocorona
4,298 posts
 
Thank you TeaJay for pointing out this new thread to me. . . looks like I will have to acquire a new amplification furnace for the Sweltering Austin Summers in some future. . . . or will Nelson Pass eventually create his own X.ICE amps? I am positive that if he ever decides to design them, they will sound just scrumptious.
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