I use the Ayre K-1xe, with my Lamm M2.1 hybrid monoblocks, and I am very happy with it. Used, they are running about $3,500 or so for the line stage version. (FYI, mine has the optional phono boards, as I run mostly vinyl. The phono boards are near reference quality and this adds a bit onto the price though, but is well worth it IMHO.) The K-1xe is now out of production, but Ayre is still servicing them, so no worries there. (It was a Stereophile Class "A" preamp just a few years ago.) A couple of points to consider though: It has no balance control, and the remote volume control is a bit noisy when in use, (i.e you can hear the motor when it runs), but of course it is silent when not in use. And the volume control design is one of the best ever made, IMHO.
The K-5xe-mp is nearly as good as the K-1xe, (or so I am told, as I have not heard it myself), and used that unit runs about $2,500. (FYI, it is a line stage only.) It is still in production, and is also rated Class "A" by Stereophile.
FYI: Ayre equipment is designed to run using balanced cables, and the M1.1 is also a balanced amp. So if you are running single ended (RCA) cables, I either recommend recabling to balanced (XLR) cables, or not bothering with the Ayre preamps, as they sound better when used in balanced mode. (I use Nordost cables both running from the preamp to the amp, (Quattro Fil, XLR terminated, interconnects), and bi-wired Valhalla Speaker cables to the speakers, just in case your interested.)
My other friends both use Lamm M2.2 hybrid monoblocks, and they use slightly more expensive preamps. One uses the ARC Ref. 5 preamp, (used about $6K or so), and the other uses a Conrad Johnson Act II, series 2, preamp, (if I recall correctly), and it runs around $6K used also. (Both of which as a bit out of your price range unfortunately.) However, if you can find a used ARC Ref. 3 for around $4,500 or so, I would stretch your budget and get it, as it is a great line stage preamp, and very nearly the equal to the Ref. 5, IMHO. (If I did not need a phono stage, I would have bought my friend's when he upgraded to the Ref. 5 a couple of years ago.)
Another friend used to use the Lamm L2 Ref. preamp with his M2.1 amps, and it is a very musical preamp. (Lovely sound!) However, it did seem just a touch dark sounding, so be aware of that. (Also, it is not a true balanced preamp, has no remote, and has two volume controls, rather than a balance control.) But if you like highly musical preamps, (and don't mind a touch of darkness to the sound), and are a purist and don't need a remote, then perhaps this preamp is the one for you. Used they tend to run around $6K too. Again, a bit out of your budget, but perhaps you might be able to stretch your budget a bit, or find a guy willing to deal, as these have been out awhile.
My two cents worth anyway.
Good Luck in your search!
The K-5xe-mp is nearly as good as the K-1xe, (or so I am told, as I have not heard it myself), and used that unit runs about $2,500. (FYI, it is a line stage only.) It is still in production, and is also rated Class "A" by Stereophile.
FYI: Ayre equipment is designed to run using balanced cables, and the M1.1 is also a balanced amp. So if you are running single ended (RCA) cables, I either recommend recabling to balanced (XLR) cables, or not bothering with the Ayre preamps, as they sound better when used in balanced mode. (I use Nordost cables both running from the preamp to the amp, (Quattro Fil, XLR terminated, interconnects), and bi-wired Valhalla Speaker cables to the speakers, just in case your interested.)
My other friends both use Lamm M2.2 hybrid monoblocks, and they use slightly more expensive preamps. One uses the ARC Ref. 5 preamp, (used about $6K or so), and the other uses a Conrad Johnson Act II, series 2, preamp, (if I recall correctly), and it runs around $6K used also. (Both of which as a bit out of your price range unfortunately.) However, if you can find a used ARC Ref. 3 for around $4,500 or so, I would stretch your budget and get it, as it is a great line stage preamp, and very nearly the equal to the Ref. 5, IMHO. (If I did not need a phono stage, I would have bought my friend's when he upgraded to the Ref. 5 a couple of years ago.)
Another friend used to use the Lamm L2 Ref. preamp with his M2.1 amps, and it is a very musical preamp. (Lovely sound!) However, it did seem just a touch dark sounding, so be aware of that. (Also, it is not a true balanced preamp, has no remote, and has two volume controls, rather than a balance control.) But if you like highly musical preamps, (and don't mind a touch of darkness to the sound), and are a purist and don't need a remote, then perhaps this preamp is the one for you. Used they tend to run around $6K too. Again, a bit out of your budget, but perhaps you might be able to stretch your budget a bit, or find a guy willing to deal, as these have been out awhile.
My two cents worth anyway.
Good Luck in your search!