Pass Labs XA60.5 or ARC Ref 75 (or Pass XA100.5)

Hey mate,

The Pass Labs gear is awesome stuff indeed, as well as ARC. Both are tremendous value in high-end sound and will give you many years of enjoyable listening pleasure. However, at the end of the day they are truly different topologies. Pass is solid state and ARC is tube! It all depends on what you prefer...
I have enjoyed the Ref 75 very much, however it can only be connected via balanced inputs. The Pass gear also has plenty of headroom and will drive virtually anything, solid power supplies with excellent current capability. It also sounds far better as your listening sessions stretch... For me though it has always been tubes, and I would prefer the ARC given that you have a capability to connect via XLR, and it would probably sound marvellous with the Sophia's.

Hope that helps!
Cheers, RJ

Big Dog RJ said:

Hey mate,

The Pass Labs gear is awesome stuff indeed, as well as ARC. Both are tremendous value in high-end sound and will give you many years of enjoyable listening pleasure. However, at the end of the day they are truly different topologies. Pass is solid state and ARC is tube! It all depends on what you prefer...
I have enjoyed the Ref 75 very much, however it can only be connected via balanced inputs. The Pass gear also has plenty of headroom and will drive virtually anything, solid power supplies with excellent current capability. It also sounds far better as your listening sessions stretch... For me though it has always been tubes, and I would prefer the ARC given that you have a capability to connect via XLR, and it would probably sound marvellous with the Sophia's.

Hope that helps!
Cheers, RJ

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I can't speak on the ARC amp but the XA-60.5 and XA-160.5 have a somewhat different presentation compared to the XA-100.5 and XA-200.5. The former have a more neutral presentation while the latter have a warmer more "tube like" presentation. I wouldn't say one is better than the other, just different. It depends on your personal preference. I don't think the lack of a preamp favors one or the other.

Ken

Not surprised, PASS is all about the music.

+1

I love my XA60.5's. Wonderful amps.

Audioseduction said:

Not surprised, PASS is all about the music.

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Is the Ref 75 brand new? How many hours on it? I find that tube gear or any gear for that matter needs time to settle in and wake up. New gear sounds constricted and tight until totally warmed up. I think, ARC needs close to 600 hours to fully break in.

majnun70 said:

Thanks, guys. I brought a Ref75 for home audition yesterday and am impressed. Well, actually, I thought it was only good at first, but it became excellent after switching from the 4-ohm taps to the 8-ohm (even though the Sophias are rated at 4.) I'll switch back to the 60.5 today, but I'd say after only one audition, it's not so astounding (compared to the 60.5) that I feel compelled to change amps.

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Hey Majnun,

If you preferred the sound of the Pass amps then why change?

The moment you change, you'll realize something else requires changing and the vicious cycle starts... you'll end up with a heap of gear and then perhaps full circle back to the original after having spent an unnecessary fortune! It happened to me many years ago.

Are you thinking of changing amps because something is lacking? Then what is it that is lacking in the sound your getting from the Sophia's? Perhaps a few tweaks are required, speaker position, cables, interconnects, or perhaps some Nordost Sort Kones, Sort Futs, or even a QX4!

You haven't really stated what it is you're after and why the main reason for change or thinking of changing...

Having Pass amps is one thing, changing from Pass to ARC is another thing. I feel that it is going in a completely different direction, which is onto tubes, and to me it sounds like you're not a tube fan.
I would try to save up and go for some larger Pass mono amps or their X.8 series amps, now they're awesome!

Towards the end of this month, I will be auditioning a top line pair of Pass monoblocks with the Audio Ananlysis Omega's. I believe this is going to be something special.
Cheers, and do let us know what you're looking for in that overall sound you want.
RJ

Will be interesting to hear your feedback Big Dog. Another guy did not like the Pass with his Analysis Amphi, he ended up with Pathos hybrids. He also liked Dehavilland. Though depends if you are demoing the class A or the AB. I understand the A is more lush, but the ABs have more grip that panels requires

joeinid said:

Is the Ref 75 brand new? How many hours on it? I find that tube gear or any gear for that matter needs time to settle in and wake up. New gear sounds constricted and tight until totally warmed up. I think, ARC needs close to 600 hours to fully break in.

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Hey Joe mate,

Where the hec have you been? I PM'ed you few months back and you never replied! I was wondering how your awesome ART amps were going with the Strads?
I bet they're just golden now, especially after a few more hundred hours of break in... do let us know will ya!

BTW, you mentioned that ARC should have a break in period of at least 600 hours; although theoretically this would be more correct for speakers and other electronics, I don't think this necessarily applies to amplification, and specially tube designs. 600 hours of break in will wear down the tubes! SS designs I could see this to be more technically correct for a proper break in period but tubes I think they're good to go after just about 24 hours. I thought the same during the past but when I contacted the designers and owners directly from equipment that I previously owned (Manley, c-j, Melos, Sonic Frontiers, VTL, Quick Silver, Cary, Cayin and Quad), their answers were "our tube amps would be just fine after half an hour!" adjust the bias, sit back and enjoy your tunes was their answer.

I believe SS it would be a different story, and that is why I clearly remember many years ago in London when auditioning a pair of Infinity Kappa's driven with Mark Levinson amps, the chappy didn't like it when I told him to switch to the c-j monoblocks (premier 8), and then switch back to the Levinson's. He didn't like the fact that the Levinson's had to be turned off and warmed up again! Anyway I walked off from the store as he was a typical snoby not wanting to accommodate the demo. Only later did I realize why...

Cheers, RJ

Big Dog RJ said:

Hey Joe mate,

Where the hec have you been? I PM'ed you few months back and you never replied! I was wondering how your awesome ART amps were going with the Strads?
I bet they're just golden now, especially after a few more hundred hours of break in... do let us know will ya!

BTW, you mentioned that ARC should have a break in period of at least 600 hours; although theoretically this would be more correct for speakers and other electronics, I don't think this necessarily applies to amplification, and specially tube designs. 600 hours of break in will wear down the tubes! SS designs I could see this to be more technically correct for a proper break in period but tubes I think they're good to go after just about 24 hours. I thought the same during the past but when I contacted the designers and owners directly from equipment that I previously owned (Manley, c-j, Melos, Sonic Frontiers, VTL, Quick Silver, Cary, Cayin and Quad), their answers were "our tube amps would be just fine after half an hour!" adjust the bias, sit back and enjoy your tunes was their answer.

I believe SS it would be a different story, and that is why I clearly remember many years ago in London when auditioning a pair of Infinity Kappa's driven with Mark Levinson amps, the chappy didn't like it when I told him to switch to the c-j monoblocks (premier 8), and then switch back to the Levinson's. He didn't like the fact that the Levinson's had to be turned off and warmed up again! Anyway I walked off from the store as he was a typical snoby not wanting to accommodate the demo. Only later did I realize why...

Cheers, RJ

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My ARC Ref 110 with KT 120s sounded much better around 150 - 200 hours, was boring till then. I was told it will get even better after 600, but I sold it before that

Well there you go! so much for ARC having to wait for 600 bloody hours!

I really don't know for what reason but I never really took onto ARC as much as I love c-j, and they sound absolutely top notch right out of the box! ARC may be using SS heaters or something that take a while to burn-in. If it is a all tube design it should never take anything more than just a few minutes to warm up and perhaps sound best after about an hour or so, that's about all. That's what the designers told me and I truly believe them. I really don't know why an ARC tube amp would take that long, I mean really 600 hours...?

I also remember contacting McIntosh on behalf of a friend's amplifier that was an all tube design, (an old MC2100 something...) and Mac said the same thing, just half an hour would do!
VTL was also the same when I had some of their older 300 series monoblocks, it just took so dam long to bias all 16 tubes!
Good night, RJ

If 60.5 is a class A, you should look at NAT Audio which is a class A tube Amp, single ended, that delivers 120w for each monoblock. I think they also have lower versions of 60w per mono. Far superior to ARC. That will give you tube power in full glory

Assuming you are in the US, contact KT Audio imports, who also does the Triangle Art TT for a dem.

Big Dog RJ said:

Hey Joe mate,

Where the heck have you been? I PM'ed you few months back and you never replied! I was wondering how your awesome ART amps were going with the Strads?
I bet they're just golden now, especially after a few more hundred hours of break in... do let us know will ya!

edit .....

Cheers, RJ

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Hi RJ,

I am sorry, Work has been crazy.

My Strads and CJ GAT/ART monos are amazing and totally fulfilling. Even though CJ says no on KT-150's, I plan on trying them in the ARTsa in the next few months. You know how good CJ sounds, put them on my favorite speakers and you have heaven on earth. I don't think that I've heard a better speaker (for my taste) than the SF Strads. I absolutely love them.

majnun70 said:

It's a dealer demo that I'm auditioning at home for a few days. Does the Ref75 have a digital meter somewhere that indicates the number of hours? All I know is that it's six months old. It has a quite a bit of scratches/marks, so it looks like it's been actively used.



Well, as I mentioned, I have no sane reason for dallying with another amp. The 60.5 truly are wonderful amps, but could it use a little more holographic imaging/soundstage? Yes; A little more body? Yes. So...I thought I'd give tube amps another try, especially one that ostensibly managed to keep the best of tubes without presenting its worst. At the level of 60.5 and Ref 75, we're dissecting relatively minor differences so I would of course be happy with either one. But I am mindful of potential improvements KT150 tubes could bring to the Ref 75, but that would require a leap of faith were I to pursue it.

The other possibility, which unfortunately is complicated by the 60.5's relatively low input impedance, is to introduce a tube preamp instead of going direct from DAC. But I accept that this could be more of a spec complication and less an auditory one. I believe I read Nelson Pass himself say that it's not something to be concerned about. In fact, my dealer thought that adding something like a Ref 5 SE would have a greater impact than switching from 60.5 to Ref 75. (I'll probably audition the Ref 5 SE next.)

In the end, if a tube amp as widely lauded as the Ref 75 does not clearly surpass the 60.5, then I suppose I must ask myself, Why add tubes to the system? On the other hand, were I going in the opposite direction, I would have no reason to go from the Ref 75 to the 60.5 (and save myself a few thousand dollars). So if indeed these amps are a lateral comparison, then perhaps it would be more fair to compare the 60.5 and the Ref 150 (or better). If that's the case, then I'd rather stick with 60.5 as I don't want to deal with more than a quad of power tubes. In either case, it seems that the 60.5 and Ref 75 are the sweetspot amps in their respective lineups.

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Ok understood. If it is body and depth you're after then certainly tubes would do it. There are other fantastic SS designs such as the Dan D's Momentums, Vitus Audio and of course the Naim Statements. However, these are very pricey and may not be for everyone's justification in purchase. Comparing the ARC gear to many other tube amplification I have owned, I can confidently say that you should give Conrad Johnson a try, if you are after body, depth, definition, clarity, inner detail, and most of all musicality. C-J has all these traits and they are simply outstanding when it comes to real value in high-end audio.

All the best and enjoy that journey!
Cheers, RJ

+1

I agree totally.

Big Dog RJ said:

Ok understood. If it is body and depth you're after then certainly tubes would do it. There are other fantastic SS designs such as the Dan D's Momentums, Vitus Audio and of course the Naim Statements. However, these are very pricey and may not be for everyone's justification in purchase. Comparing the ARC gear to many other tube amplification I have owned, I can confidently say that you should give Conrad Johnson a try, if you are after body, depth, definition, clarity, inner detail, and most of all musicality. C-J has all these traits and they are simply outstanding when it comes to real value in high-end audio.

All the best and enjoy that journey!
Cheers, RJ

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Big Dog RJ said:

Well there you go! so much for ARC having to wait for 600 bloody hours!

I really don't know for what reason but I never really took onto ARC as much as I love c-j, and they sound absolutely top notch right out of the box! ARC may be using SS heaters or something that take a while to burn-in. If it is a all tube design it should never take anything more than just a few minutes to warm up and perhaps sound best after about an hour or so, that's about all. That's what the designers told me and I truly believe them. I really don't know why an ARC tube amp would take that long, I mean really 600 hours...?

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ARC say's that it's the new teflon caps that take that long to fully break-in.

Oh! Yes I forgot about those Teflon caps...

Good point, but in that case waiting for 600 hours is a complete load of Bollocks with a capital "B". What happens when the amps are switched off after 600 hours?

After having purchased something so nice and wonderful, you would naturally want to try it out right away without further delay, and connect it soon as possible. I sincerely think that the person should enjoy the music as the system warms up, and experience the wonderful musical traits that product delivers as time passes by. Not listening to "average sound" until the 600 hour mark passes, and then oh! my golly all of a sudden it fires up and is in full bloom...

Well looks like our Bonzo mate couldn't wait and sold off the ARC before that great mark, I guess I would have done the very same thing!

I clearly re-collect the service chaps from c-j telling to allow the system to warm up because the Teflon caps take a while to sound its best. I asked how long, and Ed mentioned just about 30 minutes should do, and after that the sound will improve further with midrange being more fluid and a far greater palpable soundstage. Very true it was, and the same thing is stated in the owners manual!

Another thing that c-j mentioned is that Teflon caps are very good at remembering or "retaining" the sonic signature of tonal quality, compared to electrolytic or polystyrene caps that were previously used. Thereby, they have managed to develop an amplifier circuit that allows this sonic signature to come through with the least amount of break-in time. In addition, this sonic signature improves as listening sessions are extended. The best part is; Even if the unit is switched off after so many days or weeks, it would only take around an hour to sound best again! And this is very true with c-j gear.

I really don't know what ARC is doing with their Teflon caps but something is not right, if it takes so long to burn-in with no apparent improvement in overall sound, until the 600 mark. That's a waste of time and money to me.

Thanks for your update anyway, that's very interesting to know.
Cheers and have a good one, RJ