2. amps-preamps
  3. 148037-20132

Thiel 3.7's and Pass Labs xa60.5's- now looking for the next upgrade

I finally took the plunge and bought a pair xa60.5's mono's to drive my Thiels- and the upgrade has brought my system to a whole new level.  I was looking to get a deeper, more developed soundstage and with the Pass mono's I got more than I was expecting: the speakers virtually disappear, and you can see into the performance- the sound has a much more refined texture and everything is more fleshed out.   So now I am wondering what should be the next step up.  What I am looking to do is to get more spatial cues, and I suppose detail, to have a better sense of the recording venue and bring me closer to that sense of a live performance. 
My intention is to stay with Pass Labs and the Thiel's so I am thinking more of a preamp or dac upgrade.  The preamp is a Primaluna Dialogue Premium with Telefunken Nos tubes and the dac is a Moon 280d.   Cabling is Nordost except for the power cords to the amps which I built myself and which really did make a very marked difference- more bass and presence than before with stock cords.
Both the dac and preamp are very good in their own right so changing either to get a significant upgrade along the lines I described above rather than a sideways step isn't going to be easy.   So I am interested in any advice and thoughts from fellow audiogoners.

Here is a brief description of how my system evolved.  I was originally driving the Thiels with Mac MA7000 integrated- the power amp section is basically a hot-rodded ma252.  The first upgrade I decided to try was to bypass the preamp section with the Prima Luna and that was a revelation. The sound was transformed.   Then I started doing research on a replacement for the Mac altogether.  It took me a long time and I considered a lot of options.  What put me on the path to the Pass Labs was the suggestion from a friend, an electrical engineer that is also passionate about audio, that I take a look at a Luxman class A amp.  I had never really considered this option as the Thiels are not easy to drive but as my friend pointed out the issue would not be the watts as the Thiels are 90db but the power supply which needs to feed an impedance load that does dip below 3 Ohms across a significant portion of the frequency spectrum.   Anyway, I wasn't able to find a Luxman at my budget and it was than I got the suggestion to consider Pass- the xa30.8.  I was intrigued and called Pass and had a long conversation with them and they indeed are very familiar with the Thiels- and they too confirmed that their amps would have no problem driving them.   Anyway, just as I was mullling this over a pair of xa60.5's came up at a good price from a great a'goner and so I went ahead with that.  And btw, I have heard some suggest that Pass does not deal well with low impedance loads- it is simply not the case- not at all in fact and the proof is in the pudding: the Thiels sound GREAT.

Anyway, any suggestions and advice would be great.

Many thx as always!
pgastone
pgastone OP
79 posts
 
Hello,
And thank you.
I have heard some back and forth discussions re single ended and balanced connections- I understand the advantages of the latter although others have suggested that well executed RCA is as (almost?) effective.  Just not sure this would be such an incremental leap forward to warrant buying new cables ontop of getting a new preamp.  If at all possible I would like to stick to rca's- my own thought was that when it comes to the Prima Luna maybe the volume pot might be a bottleneck and possibly some of the capacitors.  But I will definitely look into the idea of balanced and see if can find a way to test etc.

As for the room acoustics I spent quite a bit of time trying to get that right but within the limits of decor etc.  I did room testing with REW+Mike and I managed to get a decent waterfall graph after consulting with an audio engineer and after quite a bit of tweaking in speaker placement +   carpet additions + thicker curtains (behind each speaker etc).  It isn't perfect by any means but respectable for a non dedicated room.  I also did zero in on the best placement for a sub (single) as I experimented with that a bit as well. But right now trying to see I can to improve sound from speakers standalone by replacing components up the chain.
soix
9,783 posts
 
What I am looking to do is to get more spatial cues, and I suppose detail, to have a better sense of the recording venue and bring me closer to that sense of a live performance.
Yeah, that makes sense. My guess is the combo of your class-A amps with a tubed pre is providing a lot of tonal color and density at the expense of upper-end treble or "air" that helps preserve reverb trails and better discern the scale of the recording venue.

I had a Bryson BP6 for many years, and it is the most neutral sounding component I’ve heard -- truly like straight wire with gain. When I put it in my system the whole soundstage cleared up and expanded so I could clearly "see" the entire venue with no veils. Given what you’re looking for, I think its big brother, the BP26, would be a perfect fit for your system and give you exactly what you’re looking for. Plus, it will feed your wonderful amps the full signal with adding or subtracting anything and allow them to sing more clearly and completely with their own pure voice. There’s a nice one available here now at a good price, so if it doesn’t work you can likely sell it with little or no loss.
https://www.audiogon.com/listings/lis9d507-bryston-bp26-mps2-solid-state

There’s also a Pass SP10 that would obviously have synergy with your amps, but I’ve never heard one so couldn’t say how it might help. My guess is it’s pretty neutral with probably more meat on the bones but less air and sparkle up top versus the BP26 -- but that’s just a semi- educated guess based on both brand’s house sound. Best of luck.


cal3713's avatar
cal3713
1,421 posts
 
Not consistent with your desire to avoid balanced, but atma-sphere swears by the method and makes a universally praised preamp that might make a great addition to the system.
frozentundra
207 posts
 
Good choice;

I had Thiel & converted to a Revel Studio 2. Thiel really is persnickety of electronics 

Pass brings big bass to Thiels ! 
Great resolution , but no glare 
I found Pass SS preamps to much resolution and clarity

I went with a CJ Tube Preamp and rolled tubes to get the soundstage @ depth & TUNE the sound you want 

SS power & Tube Pre is the way to go 
TONE audio magazine really promote’s the ss/Tube combo’s 

now, Throw a sub in and WOW 

my experiences say ; you are going the right way !

jeff
soix
9,783 posts
 
I have to disagree with @frozentundra -- a CJ preamp will probably just get you more of what the PrimaLuna pre is giving you now.  Not that CJ isn't GREAT gear, but for what you're looking for in the context of your system, Bryson or Pass will get you more of soecifically what you're looking for.  CJ will just add more of the same. 
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