Tube preamp choice to upgrade a Pass Labs X1

Hi Guys,

I own a Pass Labs X1 preamp to drive my Parasound Halos JC1s and than my Thiel 2.4 .. telling the truth I'm very happy about my preamp choice.
A friend of mine just bought two Pass Labs XA100 monoblock and continues to ask me to sell my X1 to match his new amps.
I'm not compelled or forced to sell him my preamp .. but I could accept this idea only if I find a Tube Preamp (line) as good as the Pass X1 .. not less good obviously!
Possibly without add lotsa money on the change
Why tubes?
Having had the solid state X1 for some time now it would be interesting to listen my hi-fi by tubes just to try.

Any good suggestion regarding the pre-owned market too?

Thanks in advance to EveryOne for suggestions/opinions

I hold the First Sound Deluxe units in high regard.Very straight forward and easy to per channel.Sound is very open and character is easily heard when tube changes are made.
Aesthetix Calypso is a real nice line stage seen one on a-gon yesterday or the day before $2500.I love mine and this thing really is class a all the way!!!!
I would recommend the ARC Ref. 3 preamp. I think it is the best preamp that ARC has ever built. (Unlike its predecessor, the Ref. 2, there is virtually no tube noise.) It is a very neutral preamp, with a nice touch of that tube bloom. It has a remote which has more features than you'll probably ever need. (I'm a bit jealous about the remote actually , as my Ayre K-1xe has a very basic remote that only controls volume/mute).

There is one for sale here on Audiogon for a VERY good price. (I have no clue who is selling it, but I noticed this, as I was somewhat tempted, but I have no spare cash at the moment.)

ARE Ref. 3 for sale here on Audiogon

Good Luck in your search!
As you will probably get around $2000-2500 for the X1, I assume that is your price range? You didn't specify.

Here are some I have tried recently (running off of a SS amp).

ARC LS26: used $4k, superb, not overly tubey, huge soundstage

Herron VTSP 1a/166: Slightly less detail than the LS26, slightly darker, but still a superb value: used $1800

Dehavilland Ultraverve 2: with good tubes, very musical, hard to beat at the price: used $1500

Maybe others to consider: a Juicy Music Peach II (one is listed right now), C-J 17 LS2, Joule LA-150 MKII, Dodd Battery Preamp. I have heard good things about the Calypso as well. One thing to note: watch the impedance mismatch and input sensitivity with your preamp/amp combo. I had trouble with my McCormack, finding a pre that was quiet in the system, which is why I have been listening to so many recently. Of the 3 listed above, the Herron and ARC had tube hiss audible at the listening position. Only the 6SN7 equipped Dehavilland was quiet. The Calypso mates well with some SS amps (like the Herrons) but not the McCormack, for example.
Find one with low output impedance (below 600 ohms if possible).
Lamm LL2. Solid bass and very wide soundstage. I've owned mine for five years never tube rolled and have been very pleased. A great value but very no frills look if you don't mind
arc 3 and lamm LL2 would be my picks as well.
TRON Syren, Tom Evans Vibe, ARC Ref 3 and Lamm LL2 would be my picks. With the current USD/GBP exchange rate, buying a boutique british amp such the TRON or Tom Evans makes for better value.