PassLabs 350.8 versus Ayre MXR Twenty

What speakers are you using?

Dali Epicon 8

Do nothing until you get use to the sound of your new preamp.

Audio Research Preamps and Pass Labs Amps are known to be Killer Combination.

Years ago I ran the Audio Research Ref1 with Pass Labs X350 and it was a killer for its day. Highly recommend a listen preferably before you buy.

Have heard the all Arye Ref system and yes it sounds fantastic but you already have the AR Ref 6. The Ref 6 will take some 600 hours to sound its best.

On 8-4 of that same Long list of amp thread,  he says that he sold the 350.8

@vindanpar I think you really should listen to both amps with your pre and speakers.

But here are my $0.02 for what it’s worth.

I very nearly got some non Twenty MX R’s. I ended up with the X350.8

I have not heard the Ayre MX R Twenty but have heard the VX R Twenty in a demo system, paired with the KX R Twenty, driving Aerial Acoustics speakers. The dealer A B ’ed them with some Pass XA 200.5 monos. The Pass were driven by ARC Ref 5 SE. In that setup, I preferred the Pass and ARC pairing overall. It sounded fuller and more musical. The VX R Twenty was more articulate and refined. There was more inner detail. I wouldn’t have called the VX R Twenty lean but it did have less body compared to the Pass.

I had my initial shortlist down to non Twenty MX R’s and a X250.8. In my previous system with Dynaudio speakers and a Cary SLP 05 pre, I preferred the non Twenty VX R to a Krell FPB series amp. The highs were less strident, it was slightly rolled off - in a good way. In another demo system, with Avalon speakers, I also preferred non Twenty MX R’s to a D’ Agostino Master Power Classic. The Ayre had a better musical flow.

However, the deal I had on some non Twenty MX R’s fell through and I ended up getting a X350.8. The Pass was more full and visceral sounding than the Ayre with great timbre all throughout. The bass slam was impressive - not so much as the older Krell type slam, I don’t think anything will beat that - but more textured and less of a one note presentation. If my memory serves me, the treble is smoother and more extended than the X 0.5 series, where there was still some hardness and grain in the highs. However, the midrange is not as warm as the X 0.5 series. Vocals are more clear and natural sounding but the midrange emphasis that made them so alluring on the X 0.5 series is not so much there.

Overall, the Pass will probably have better grip and control of hard to drive speakers than the Ayre will and give you better bass slam and a fuller presentation. Although Dali Epicon’s aren’t as difficult a load as say Dynaudio. I have heard them successfully driven by medium powered tube amps.

Strangely enough, one of the pro’s for the non Twenty MX R’s for me was also the smaller form factor and easier transportability you cite. The X350.8 is big and a heavy 2 person load.

I could have lived with either the non Twenty MX R or the X 350.8 in my system. I can only imagine that the Twenty versions are better, especially if they improved the bass performance from what I have read. I wouldn’t describe either as tube like as many do. At least not in the way Conrad Johnson amps sound - that is another sense of harmonic richness that no solid state amp can give.

Audio Research Preamps and Pass Labs Amps are known to be Killer Combination.

I agree that these companies make a great combination. I am running a ARC Ref 5 with a pair of Pass Labs XA-100.5 mono-blocks.

Cary Audio SLP-05, Passlabs XA60.5 driving Goldenear Triton Ones.
Detail, spaciousness, and clean tight Bass to die for with the Triton's built-in 1600 watt sub amps and six bass drivers.

I agree with others that suggest to audition both amps in your system, but realistically I don't know how you arrange for that.

FWIW, I owned the Ayre MXR-20s and the Pass Labs X350.8 at the same time.  My speakers are Rockport Altairs.  They're not a difficult load, but they need an amp with ample current to correctly manage the 15 inch woofers. The X350.8 did a better job with this which led to better speaker coherence so there was less gaps at various frequencies.  I used a decibel meter and test tones from 10Hz to 50KKz (way beyond my audible range and likely my dog's as well).  The Ayres had measurable gaps (lower DB levels) in the lower frequency range 50Hz - 120Hz area.  I think this is why I got better slam and a better overall presentation with the X350.8.

Then there's the cost factor.  Even if the 2 amps were the same cost, I'd still probably choose the X350.8.  At the retail and pre-owned prices of each, it makes the X350.8 a bargain IMO.

I have since moved on to a Boulder 2060 which I'll never part with, but it is large and heavy and likely overkill for your speakers.

If you can't audition both, then my vote would be for the X350.8.  Hope this helps.  

@cycles2 you are probably the only person i know who has owned both amps at the same time.

As I said, I have heard the non Twenty MX R's.

How would you compare the Twenty MX R's to the X350.8 sonically driving your Rockport Altair's - other than the control factor?

I considered getting the Rockport Atria's at one stage. Super heavy - it took 2 guys to move it into position at the shop.

@mikey8811 As I mentioned above I consider the X350.8 to be a bargain. Don't believe all the tube-like characteristics that Ayre claim in their marketing material. It's just marketing speak.  IMO, if an amp doesn't get the bass foundation correct, then you're always looking for what the problem with your system may be.  Once I replaced the MXR-20s with the X350.8, the bass coherence improved which improves the overall presentation.  I used to own Pass Labs XA100.5 and I know the X350.8 is Class A/B and technically shouldn't be as good as the XA100.5, but I've had a few people tell me they believe the X350.8 is a 'giant killer' in the Pass lineup.  
The difference with the Boulder 2060 is that as you increase the volume, it just gets louder and there's no difference in sound characteristics. The X350.8 and the MXR-20s seem a bit strained as you increase the volume.  Probably as they switch over to Class B, which is easy to tell on the X350.8, and a mystery on the MXR-20s.
Remember, most of the weight of the MXR-20s is the aluminum chassis.  I don't claim to be an electrical engineer, but when you open the hood, it's easy to see why they don't generate lots of current - there's just no muscle underneath.

  



 

@cycles2 thanks for confirming what I heard at the showroom demo.

As per my post above, I preferred the Pass XA200.5’s driven by ARC Ref 5 SE to VX R Twenty with KX R Twenty. I found the Pass had a fuller, more musical sound and the Ayre comparatively leaner, perhaps owing to the bass coherence you cite.

I am pretty happy with the X350.8 but as you know in this crazy hobby, you always wonder about the ones you didn’t get....

My speakers are the Vienna Acoustics Kiss which in spite of a low impedance dip, is an easier load than the Rockports, so the strain at high volumes is not as apparent sonically even though I do see the meter twitch and leave Class A.

I do enjoy the speed and slam the X350.8 gives (someone else had a very apt descriptor of "ballsy") which I have been told is a characteristic of Pass Class AB vs Pass Class A amps. I am unsure if this is true as I have not AB’ed them in the same system but do remember the XA 100.5 being very musical if a bit too laid back with some older Sonus Faber speakers.

Thanks again

I found the Pass had a fuller, more musical sound and the Ayre comparatively leaner, perhaps owing to the bass coherence you cite.

I have found the same to be true.

However, which one would work best for the user would depend on his associated gear, and his musical tastes.
Many folks love the Ayre gear with warmer speakers like Vandy's.
Any speaker/room interface that might have a bit of bass bloat, may work better with the Ayre.

In the end, it's all about balancing a systems resolution and musicality to suit your own personal tastes.

@vindanpar, all Class A/B amps change sound characteristics when they transition from Class A to Class B. However, we're talking pretty high volume levels depending on your speaker sensitivity.  I wouldn't worry about it as you may never transition to Class B at your listening level.  The sound isn't bad, it's just a tad different.  Besides Pass Labs are a safe investment in this crazy hobby. They're easy to sell and hold their value if you keep it in good condition and save your packaging. Are you looking at new or a pre-owned 350.8?  For a pre-owned in good condition, you should expect to spend about $8k - $9k.

Maybe it's because you have speakers at the high end of the high end you heard the strain?

I have never had the opportunity to critically audition the Pass Labs 350.8 but did have an all night session with with the Ayre MXR-20, comparing to the PrimaLuna Dialogue HP, and VAC Phi 200s. After many hours of auditions, switching between Wilson Sophies, Quad ESL 988s and Vandersteen Quatros, Myself and fellow audiphile friend came to the same conclusion that on all speakers that we compared - the VAC, (especially running through the balanced outputs) had the largest deepest and most musical stage, while the Ayres had an impeccably clean, detailed, slightly dark character by comparison. The PrimaLuna fell someplace in the middle - but a bit short of both the Ayres and the VACs. While the Ayre MXR-20s are very, very impressive in terms of detail, imaging, dynamics and a dead silent background - I would not say their sound was particularly tube like. Got to agree with jmcgrogan2, the Ayres did sound incredible on the slightly warmer Vandies.
Jim

Not heard the mxr 20 in my system.  Never heard pass 350.8 but heard xs300.

i have the Boulder 2060 like cycles.  I understand what he means, turn up the volume and the Boulder expands the stage and moves objects towards you rather than just making everything a big amorphous stage. Kinda like you turning up the volume and it essentially remains the same.