What tube pre-amps pair well with Pass amps?

Billtro

What’s the budget? New or used? 

I use use a PS Audio’s BHK Signature preamp with a pair of Telefunken 12au7’s from the early 1960’s into a Pass Labs xa30.8 class a stereo amp and it sounds amazing. Hope this helps.

Scot

Check out the KR P-135.  Has XLR ins and outs.  Review at positive feedback is glowing.  
Full disclosure I am a KR dealer but I think it would be a cool match.  

Scothurwitz

Thanks for the reply.  I'm currently running Prima Luna Dialogue pre-amp and 2 HP amps as mono blocks, which I intend to keep (read tube rolling fun) in a 430 square foot room.  The PS audio pre-amp has been on the screen, as I have their DMP and DAC.  With this matchup, do you think the Pass Labs XA 30.8 has sufficient power for the Sopra 2's?  I've always been intrigued by Class A amps and its on my bucket list. 

One last thing, do class A's handle sub-woofers? 

Thanks for the lead VERDANTAUDIO.  German company?  Its a big world out there.

The most helpful information you could provide would be what sound qualities you value and/or would like to improve upon.  Without that this is really just a shot in the dark. 

SOIX, you are absolutely correct.  I've just relocated and am in the process of addressing my new room's acoustics.  Treatments are on order and until I get the set up I won't really be able to tell where I'm at.  Until then, I'm just searching for possible ideas.  Since my current system is all tubes, I'd like to explore SS with a little more slam for complex and/or dynamic music.  

Thanks for your reply.

I have a Pass XA30.8 paired with a VAC Renaissance MK5 preamp.  Works very well together musically bolstered by design compatibility in impedance, gain, and both having fully differentially balanced circuits.  Drop a pair of NOS 6922 into the VAC and you get the quietness of a Class A SS amp paired with the tubey goodness of the VAC.  A perfect pairing in particular with speakers around 8 ohms and 90dB sensitivity in my experience.

Linear Tube Audio ZOTL Preamp

+1 on the LTA  MZ2 with a XA30.8.  This is a very good pairing and drives my Vandersteen Treo CT’s with finesse and power.

Linear Tube Audio Microzotl Reference Pre-Amp.  It's a wonderful piece of gear.

+1 on the LTA Mz2 with XA-25

For many very satisfied years, I had a Pass Labs X 250 paired with an Audio Research Ref 1...I never wanted anything else until I down-sized to a smaller house and listening room...

I am happy with my Audio Research Ref 6 pre and Pass Labs XA 60.8.  Can buy the Ref 6 used.

I have a LTA MicroZotl paired with my First Watt F7 and it is a great combo

The LSA website recommends speaker sensitivity as:

Critical listening environments: 105db sensitivity and above

Smaller rooms / lower volume levels / non-critical listening: 97db sensitivity and above.

Aren't those levels speaking to horn speakers? 

KR is a Czech company which helps keep the prices down a bit compared to Germany. They are best knows as a premium manufacturer of tubes and their Kronzilla power amps.  

I sell a lot of their tubes.  Quality is extremely high though as odd as it sounds, the KR amp does really well with EML 45s.  KR tubes are best when the current can be increased when biased which doesn't happen in a preamp.  

PM me if you want to discuss pricing.  

Currently using a ARC Ref 5se with Pass 260.8's, to me a very good combination

VAC for best sound.

You've got a smattering of responses and I'll add mine. When looking for a pre to pair with my first watt f4, I read a lot about tubes and topologies and eventually settled on 6sn7 based units. If you want a balanced design, I'd look at atma-sphere's offerings. For single ended, I was choosing between de Havilland, Don Sachs, and supratek. I eventually ended up with the Don Sachs and it improved everything about my system performance. Didn't get to demo the competition, but from the reviews, I don't think you can go wrong with any of those choices. The 6sn7 is nicely linear and sweet. I'll probably still try out a supratek at some point...

I heard the pass xa25 with Backert tube pream it’s a superb combo , all the accolades you mentioned were all there and some...

A few iterations back, I had a pair of Sopra II's, the Pass XA60.8's, and Aric Audio's Motherlode preamp...it sounded fantastic! Fast forward to today, and the only piece of gear still in the system is The Motherlode. Call Aric and you will not be disappointed. 

+1 laaudionut. I own the Aric Audio Special preamp. Using it now with a BEL 1001 MK5. Plan on getting a Pass XA25 in the future. 

I'll just note that the aric audio preamps are also 6sn7 based. I'd love to hear one, as every review is very positive (and I agree with many of his well-advertised design options).

+2 for the Aric Audio preamps! @laaudionut, @mesch 

Since we are on the topic of the Pass Labs XA25, I am now running a souped up Aric Audio Special 6SN7 preamp with mine, replacing the already excellent Backert Labs Rhumba preamp, which I used for 3 years.  This was Aric’s own preamp that he used to voice his latest Motherlode II preamp, and it retains most of the Motherlode’s sonic characteristics.  It’s an amazing match with my XA25. 

If Nelson pass wanted tube preamps, he would have made them  Stick with Nelson's designs. He is the best amplifier designer-engineer there is so why mess with tubes?

I will agree on his ability to build some of the best solid state amplification afforded the audio community. However, I have had both the XP20 and XP30 in my system(paired with the 60.8's), and they are anemic and lifeless in offering.

You may want a differential balanced preamp to bring out the best in Pass's balanced designs.  I use an AtmaSphere MP-1 preamp with XA 160.8 monoblocks and a modified XP-25 phono stage.  It sounds very clean and can be contoured to taste with tube rolling.

@1markr My pre is about 2 year old version of the Special. Bought from Aric as a demo. How was your preamp 'souped up'?

Nelson Pass doesn't design active preamps

@keithr Pass labs most certainly does build active pres: https://www.passlabs.com/product_tags/line-preamps/

The xp20 is capable of 10db of gain.

And technically Kent English is primarily in charge of designing the company's award winning preamps.

+1 dgarretson I would use a balanced pre with one of Pass Labs balanced amps. The XA25 is single ended. 

@mesch

I got these details from Aric: the upgraded "Special" has: "Miflex PIO capacitors, all film cap power supply, heavy choke filtering, damper plates for the 6SN7s and features the Vishay resistors as well, but it has the standard iron-core transformers and ALPS remote volume control."

@billtro please excuse my short sidestep to your thread. Wish you the best in your search. 
Thanks 1markr! One day I may talk to Aric regarding upgrade. Love my Special as designed. 
One needs to know what one wants to achieve prior to throwing resources into upgrades. 

Boulder power amps and Focal speakers are a match made in heaven.
I use a Wavac pre amp with my 2060 but also looked closely at VAC pre amps.
Sonically the Wavac - Boulder combo is spectacular, but on paper there are better matched preamps for the Boulder

I’ve run my First Sound preamp with both the X150.8 and the X250.8 with great success.  Outstanding match in all sonic regards.  

Many years ago , when the X250 was in production, I used a Lector Z.O.E preamp. I think it’s an Italian audio company. Anyway, it sounded really good after trial and error with various nos tubes. I ended up selling it to “upgrade” but it was manhandled during shipping. So sad. Anyway, when my friends come over to hear my new gear a lot of them will compare the new stuff to the Lector/Pass combo , ie , xx isn’t as extended as your old setup. Sort of became a gold standard for them

Anxiously waiting my Nelson Pass Designed Korg B1 tube preamp!  It should be shipping soon: https://diyaudiostore.com/collections/b1-buffer-w-korg-triode-pre-amplifier
I heard one at his place in front of a SIT-3 and an F7 driving Tannoys.  Sublime!

I use my Pass XA-60.8 amps with an AR 5 preamp and YG Kipod speakers and the sound is exactly what I want.  My Digital gear is Esoteric N-01, K-01 and the Brinkman Nyquist II.  I am not a vinyl guy.

The Aric audio preamps seem to be built well with a good circuit design.Can they optimize it for the pass amps when you order one?

@invalid Thanks for the kind words! Offhand, there is no optimization or tweaks needed for any of my preamps to mate seemlessly with any of the Pass amps. I have dozens of happy customers currently using my line-stages with Pass amps without any issue with integration. Feel free to contact me via my website if you have any other specific questions! Best wishes, Aric

Wow!  Talk about a wealth of info!  While I'm still in my researching phase, I want everyone to know that I appreciate each of you for taking the time to share your experience and perspectives!

I have Pass Labs XA60.5 amps. My preamps are both Cary Audio - SLP-05 and SLP-98P F1 version. The modified SLP-98P sounds a tad better, so the SLP-05 is off to Cary for the Ultimate Upgrade. It should sound as good or better than the 98P when I get it back. The 05 has more features that I like - HT bypass, balanced operation, no phono.

billtro

Yes, the xa30.8 has unbelievable drive capability. I used to have a pair of Magnapan 3.7i's with a pair of their DWM woofers wired in parallel to the xa30.8 and that means it was a constant 2 ohm load that the amp "saw" and it drove that setup effortlessly and sounded so musical it wasn't even funny. The are a lot of lesser amps that would have just shut off with that setup. I enjoted that system for 3 years. I am now using a pair of Eminent Technology LFT8B's with that same amp and I love it. Those speakers are 83db efficient and it also sounds amazing. 

I've had a lot of good preamps over the last 5 years such as Parasound JC2, a Mac C52 and a Rogue RP7 and others but the PS Audio BHK preamp was so much more musical with much better tonal color and much more accurate timbre. It just draws you into the music. I think the PS Audio is a very underrated preamp for the money and maybe gets overlooked by audiophiles willing to spend up to $10,000.00. You have to put a pair of vintage 1950's or 1960's nos tubes in it (I used a pair of Telefunken 12au7's) and it just comes to life. It will surprise you, it did me. Retails for $5995.00 and you can pick them up used for between $3 - $4000.00. Bascom H King has been designing tube based electronics for over 50 years! He knows all the tricks. Great preamp for the money. 

The Pass amps sound best when with balanced interconnects. In my opinion, Pass class a/b amps sound very good but their class a designs are magic. If you can take home that xa30.8 and listen to it in your own system I think you'll wind up getting one. Their xa25 is supposed to be a giant killer if you don't run balanced cables. Nelson Pass is another guy who's forgotten more than a lot of these other amp designers may ever know. The guy is a genius. Hope this helps. Good luck.

Scot

I would agree with laudionut   I've had both an xp20 pre and an xp30 and they did some things very well such as great dynamics and very quiet and very transparent but they lacked musicality in my opinion. I found them to be quite sterile and lifeless and I'm a huge Pass Labs amp fan. I used them both with an xa30.8 and was very disappointed. Sorry Wayne. 

Scot 

Lta microzotol ref pre + xa25

Very curious to do a back to back comparison with the 30.8. 

@koetsue13
"Anxiously waiting my Nelson Pass Designed Korg B1 tube preamp! It should be shipping soon"

Cool. I noticed a few reviewers giving it a go. Does yours have the 6P1 Dual Triode device? http://https//6moons.com/audioreviews2/firstwatt4/2.jpg

Hi cal3713

Just to set the record straight, Kent English works for Pass Labs in an administrative capacity, Wayne Colburn designs all of their line level preamps and phono preamps. Take care.

Scot

@scothurwitz Thanks for posting that. My mistake actually just occurred to me yesterday and I was going to hop on to correct the error. Always great to make a mistake like that while correcting someone else's. Much appreciated. And apologies to Kent and Wayne for the mix-up too.