Which preamp for a pass labs?


I bought a Pass Labs xa 30.5 and now I have to choose between a Pass Labs XP 10 preamp or an Audio Research ls 25 MK2. Which one would you choose? Which balanced cables do you recommend to connect pre and final?
Thank you
128x128mizioa
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I’ve used both a Cary  Slp05 and an Atma Sphere MP 1 with very good results with Pass amps, currently 2 30.8s. Preferred over any solid state pres including Pass. I run balanced Kimber selects, have 7 meter run between amps and pre.
Like the OP, I use a Pass XA 30.5. My phono pre is a Pass XP-15 and my Pre is a Pass XP-10.  Even on the high gain setting on the phono pre, the system is very quiet, black backgrounds, I'm sure due, in a large part, to the balanced design and CMRR as Ralph points out.  The connection between the XP-10 and XA30.5 is a 25 foot run of Canare 4e6s star quad XLRs which sound exactly like a shorter run of AQ SKY balanced cables in my system.  This also agrees with Ralph's statement about the benefit of a balanced design and cheap cables.  

Hopefully some day I will sell the XP-10 and XP-15 for an Atma-sphere MP-1.

-Karl
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In your opinion, with a solid-stage preamplifier, is it more suitable for greater liveliness and dynamics?
No. Its not about tube or transistor, its about execution.

This is my opinion, but ARC is merely competent but never state of the art. Their circuits tend to be overly complex and have often left me scratching my head wondering why in the heck they did something the way they did as usually its pretty easy to spot areas in their schematics where performance has been left on the table, apparently with intention.

For example most of the ARC preamps now include differential input circuits, but every one I've seen has parts installed that actually reduce CMRR (Common Mode Rejection Ratio) because they limit the differential effect in the circuit! The more differential effect you have, the lower distortion, wider bandwidth and more gain you get.

This is part of why I asked earlier why the choice was limited to ARC or Pass. There are other tube preamps out there that are more suitable for driving a Pass Labs amp IMO/IME.


In the end I bought an Audio Research Ls 26. I've been listening to it for some days but it seems to me that the result is a music that is too soft and with little dynamics. In your opinion, with a solid-stage preamplifier, is it more suitable for greater liveliness and dynamics?
Thank you
My OPINION.... Even if electronics are fully balanced from end-to-end, it doesn't matter. The "balanced" effect is all myth and hype. Noise is NOT appreciably reduced since it is in the system REGARDLESS of the design of the interconnects. It is just there. Shielding is the only way to help reduce noice, but it will not STOP noise. So the bottom line is balanced is a complete myth and waste of money. Better to spend money on good single-ended components with top performance rather than wasting it on balanced components.
Opinion yes, fact- no.
Fact: a differential gain stage has up to 6db less noise than its single-ended counterpart. If you have more than one stage of gain, how many db less noise is possible then?
Fact: a differential gain stage has a spec called Common Mode Rejection Ratio (CMRR); if there is a noise common to both the inverted and non-inverted inputs, a differential amplifier with a high CMRR value will be shown to have far less of the noise signal (down by the value of the CMRR) while a single ended circuit will not. Our input circuits tend to be in the high 90s to low 100s in this regard.

Historically, the balanced line system is what made long distance telephone possible. It also ushered in the era of high fidelity, as for the first time the recording gear could be remote (not within 10 feet) from the performance being recording, without degradation. All of music is recorded with balanced line; its not hype.
My OPINION....  Even if electronics are fully balanced from end-to-end,
it doesn't matter.
Is this your scientific OPINION or from PERSONAL experience?
Because EVERY time I moved from single ended to balanced connection on equipment that has both, the sound improved in a number of ways.
My OPINION....  Even if electronics are fully balanced from end-to-end, it doesn't matter.  The "balanced" effect is all myth and hype.  Noise is NOT appreciably reduced since it is in the system REGARDLESS of the design of the interconnects.  It is just there.  Shielding is the only way to help reduce noice, but it will not STOP noise.  So the bottom line is balanced is a complete myth and waste of money.  Better to spend money on good single-ended components with top performance rather than wasting it on balanced components.


I am in the 'Tubes Somewhere in the system" camp.  Pass SS power amp and a tube pre is a sonic match made in heaven.  (I run an Ayon Eris into an X150.8).  ARC, Cary, Ayon and I am sure quite a few others.  Uber-tip:  A Pre with 6H30 tubes is liquid gold.
Cables:  Go for something cheap and cheerful. 
OK- why just ARC and Pass- no other choices?

I would suggest a balanced tube preamp for a Pass and there are plenty out there.
All the "balanced" hype is pure BS.
This statement is false. To start with there is no hype. To end with, the balanced line system was devised specifically eliminate artifact from cables. If you like one cable over another in an audition, then you know what I mean by 'artifact'.

I am constantly amazed that there is any push back at all on balanced line- you'd think audiophile types would love a cable that is simultaneously inexpensive, tonally neutral, low noise and revealing, in any length. Why pay more for cables that don't bring home the bacon?

I am using ARC Ref 5se with Pass 100.5's and switch with an ARC Ref 75. I am actually having a hard time picking which I like better. When I was looking I was told, that the ARC LS25 MKll is a very good preamp and the Ref 3 just a little better. I never considered a solid state Pre amp, because I like the warm sound from the tubes. I will admit I have been an ARC fan since the SP 3.
Actually at this level these components are balance from input to output. There is no balanced to single conversion going on. Both the LS25 and the Pass X amps are meant to be run balanced but will work with a single ended connection. But that's really kind of a waste of what these components can do. If you run the LS25 single ended you're literally only running one half of the preamp.

If you're going this route go buy good XLR cables even for short runs. I agree a lot of components are single ended internally but not the ARCLS25 or Pass amps. Otherwise you'd be better served with components that are meant to be used single ended. It's part of the reason these boxes cost what they cost.
All the "balanced" hype is pure BS.

It has it's place with long runs of interconnect >10mts for less noise.

But you are more right than you know, when you say it's BS.
  
As many sources, preamps and poweramps with balanced inputs or outputs are fake!!
In that they are single ended topology circuits, with just an opamp on the input or output to make them have balanced inputs or outputs.

All along you'll get better sound using the single ended inputs or outputs on these because then you are bypassing those opamp/s.

Cheers George   
If I had to choose between an ARC LS 25 Mk2 andd a Pass Labs XC-10 (or -12), I'd get a Herron Audio VTSP-360.  Smokes both and takes no prisoners.  No point in using "balanced cables" since they do nothing at all to improve the quality of a standard 2-conductor.  All the "balanced" hype is pure BS. 
I was looking to upgrade from my former Modwright 9.0 SE and took home an ARC LS25 MkII and overall preferred the Modwright. Took the ARC back and ended up with a Modwright LS 36.5 which works great with my Pass X250. The ARC was a fine preamp but just didn’t excite me much like the Modwright’s do. Clear Days balance is a great cable especially for the money. Still have Clear Days but prefer my Wywires Silvers now.
mizioa
Which preamp for a pass labs?
Try a Schiit Freya for a trial period, it’s got all the flavours, passive, solid state, and tube switchable while your listening, your bound to find the right combo for your system.

It also has SE or XLR inputs and outputs, the best volume pot there is, a 128 relay switched, even has a remote.

It’s not a glitzy show piece, but it’s got what counts, under the hood, at a very reasonable cost. $699 it's a steal.
http://www.schiit.com/products/freya

Cheers George

We are a dealer for Pass and we had the chance to audition the new XP12 
it Utilizes trickle down technology taken from the flagship XS  pre-amplifier 
It is a very open and warm extremely transparent preamp please contact me as I can discuss this with you further
I have a Pass XP-20 preamp, which I consider the finest preamp have ever owned. That includes a CJ Premier 17LS2. I owned an XP-10 for a while and I thought it was quite good- and the XP20 is better. 
Nothing wrong with an XP10, but I've compared it with others and found it expensive for what it is.  I also like the LS25 MkII,  In Solid State you might look at a T+A Elektroakustik,  used they will fall in the price range of the others. 
Neither?

Conrad Johnson.

Sorry, I find the entire current Pass line as way too flat and colorless. If you are going with an amp, I might strongly encourage you to look elsewhere for a pre, unless you were a big fan of the old AR house sound, in which case Pass or old AR makes sense.

Best,

E
I would suggest Pass  either an xp10 or 20 would be a perfect match. As for cables I am using these and they are excellent regardless of price.

https://www.dysonaudio.com/collections/facemelters

Enjoy the music
Chuck 
@mizioa  Going (used) with the XP-10 makes a lot of sense. I'm very happy and pleased with my XP-20 and XA-30.8 pairing. Support from Pass has been terrific (for questions) and both components are so well built, including the remote.

I've also owned ARC gear and have been very happy with those components.

Either way, you are making a great choice. I was looking at other preamps and decided to maintain in-house synergy, but that isn't a necessity.

As for balanced cables, that depends on your budget. Many threads here at Audiogon on cable preferences. I am using Cardas Clear Reflection and Audience Au24 SX cabling. You have many, many choices.
I ran an LS25 MK1 into an X350 and thought they went together really well. I now use a Ref2 with the X350 and again a good combo. It's like McGrogan said, they complement each other very well.

The LS25 is now running an ARC VT100 and the sound is much leaner than it was with the X350. I'm still trying to work that out. It could just be the VT100 is just getting tired. I bought it used.

I will admit I've never tried any of the Pass preamps. It probably wouldn't be a bad choice. The LS25 does have an incredible amount of input/output options so that might also count for something.
Alright, I'll go against the grain and say ARC. I am one of many folks who use ARC preamps with Pass Labs, and I am very happy, I think they blend very well.
The Pass Labs house sound is very full and warm, while the ARC sound is high resolution.
In my opinion, all ARC is too bright for my tastes, and all Pass Labs is too dark for my tastes. Together, the balance is just right.

Obviously, others will have other opinions.
I would get a Pass preamp. Nordost makes good cables IMO. Pick the one that fits your budget.