It is a good idea to purchase a vintage tube pre-amp.

Since the new one are pretty expensive and what I can afford is an old one with budget of US$2000~3000. Since I don't have much knowlege on electronics, but I have authentic listening capabilities. Is it good idea to buy an old gear of tube pre amp. around 10 or 15 years such as Audio Research SP-15 or something similar (the newer one within my budget is better of course).  I would prefer a stable, long time use gear without much trouble.
There are many new and used preamps in $2000~3000 range.
First, some questions; what amp are using, do you want balanced or single-ended (RCA) input/output? Do you seek a warm, "tubey" sound or more neutral and transparent?

You may not need to go back 10-15 years for used. It depends on the quality of your components you are adding to. For example, Your budget could get you a nearly new Conrad Johnson...

or a new Atma-Sphere pre with phono stage...

or an amazing deal on an ARC...

IMO, a 10+ year old preamp is a good value, but realize that it will need to have some internal parts replaced due to age. So add about $300 (plus tubes) to the price of an older component.
I think it certainly can be a good decision if you purchase for the right price taking into account tube replacement and replacing/upgrading parts as noted by lowrider. BTW you mention the SP15, do you require a phono stage?
For $2-3K you can get a really good used tube pre, especially if you don’t need a phono stage. But even if you do. Not to disagree w my esteemed colleagues, but most tube pre-amps (with some notable exceptions) are very easy on tubes, so I would not necessarily believe that you would have to budget for replacements. Even if you so, there are many good new stock small signal tubes available w/o breaking the bank. There are lots of good ones for sale now; in addition to the CJs and ARCs, there are models from Audio Note, BAT, and Modwright available well within your budget.

BTW, it's my opinion that a good pre is the heart of a good system, you can't go wrong here with getting the best you can afford. 
I like my ARC LS-25 Mk II, which ocst $2500 with new tubes used from a dealer.

You can get different sound than ARC, but it is not clear to me that you can get better sound.

Other options include CJ (phatter sound)

or maybe Primaluna tho cost may not fit your requirements.

I like to stick to companies with established track records, good support, and a history of long development towards some euphonic goal.
I've owned a melos 222 preamp for about 20 years. I had it looked at last year and upgraded some switches, the volume pot, umbilical cord, added an IEC, etc., to great result. Although it's not the level preamp you're looking for, my point is that it's worth upgrading old quality equipment, if you like it.  
After I purchased a 2nd Accuphase C275V, I find that it grade in sound is unable to compare with the pre-amp. I owned more than 30 years ago.  The problem is the old tube amp. has problem occasionally which required maitenance which is trouble some for me for I am not an engineer. Without comparison, you don't know how good my old tube is. The SS's slim and lean sound reproduction makes me tasteless.
Also, thanks for all of you for your kind response and help or suggestions. Best wishes for you to have pleasant listening too.
The classic SP-15 is a classic ARC pre & cherry ripe for high end mods imho. Bare is mind, it is quite old, so unless you find one already refurbed unit, I would look for a stock example in good nic & save up for a refurb incl: higher end caps, some nice WBT rca jacks, Furutech IEC & some nice matched NOS tubes. The only caveat is you’ll need single ended cables. Also, the included phono stage is ok, but i’d look for something like a 2nd hand ARC PH3 SE if you want a decent matching phono stage.
For $3000, a PH-3se phono stage and an LS-16 line stage might be better than an SP-15, don't ya think?
@bdp24, Sure. But the SP15 would be fun to go all out modding ;) The look and vintage of the two components would match up nicely too.
True. I love the look of matching faceplates, especially ARC's and McIntosh.
Tks for your kind opinion, in order to prevent troubles, I am trying to avoid too old models. But as you know, the new models are quite expensive and one of my friend also gives the new models bad review in sound reproduction.  Such as R3, the dealer tells me that when the LED is in trouble, there is no parts for replacement........
Faust, a happy medium might be something like the LS16 as bdp24 suggested, or even a later model. I'd keep an eye out on Agon, USA Audiomart & Ebay. My only advice is be cautious about the seller's feedback and condition of the amp.
I would have said a year ago that your best choice would have been to go used (Thor, Supratek, ARC, older CJ etc.)
This could be the golden age of inexpensive preamp! The rhumba, the Line Magnetcs Micro zotl2, the new Modwright, even the Pass headphone amp integrated does some things better than their statement preamp!
@baranyi, I'd second the Modwright SWL 9.0 Anniversary Edition which is $2900 mspr + $300 for the optional phono stage (with the caveat there are no balanced connections). The Backert Labs pre also looks like a bargain.
                 They are both great pieces! I conflated a couple of preamps in my last post. It is the Linear Tube MicroZOTL2 ( which I have on order and obviously thought was sensational) and I'm sure Line Magnetics must have some tasty offerings in that price range. Terry London who is a great friend and a reviewer for Home Theater Review has written about most of these. 


After using a Accuphase C275V SS pre, I find my old tube amp. sounds much better with thick, solid, string which unlike SS's thin sound reproduction. I think, I'll try to find a bargain good tube.

No need to buy a vintage tube preamp when Don Sach's is offering a SOTA tube preamp, based on the venerable 6SN7 octal tubes, for around $2K, plus/minus.  I got one of his prototypes and have had him incorporate his upgrades to his current offering, and it is a stunningly fine preamp.  Google Don Sachs and look at this line stage. It is by far the best preamp I have ever heard in my system by far and I have had more vintage tube preamps that I can recall.  I reckon I could not improve on its performance for under ~$10K.  Good luck.  

I have some vintage  mac's   ss and a Fisher 500c  tubealong with some Dynaco st70's and wm5's they all sound great but these old tubes are nice.
For 1500 to 2000 you can get a nice Fisher that's bee completely restored.
Mine is hooked to some vintage altec's and sound  they great.
I know that's not  slick audiophile gear but it will put a giant smile on your face.
I have some audiophile friends I recently met, we've been  getting together aND listening to one guys high end gear.
It's  very nice , very crisp all the right things.
After listening to some Pink Floyd on his I came home to the 500 and heard what PF is supposet to sound like.
His just seems to have no bottom end, I'm  no bass guy but it just did not sound right on his.
I loved my old MFA Magus. Not in good repair at the moment but when it was good it was very good. I'm looking to sell it if someone wants a worthy project. Or I'll get it up to specs and then sell it. I had issues with my power amp so switched to an integrated to simplify my electronic life. 
I previiously had an Audio Research LS26 which sounded superb.  Plus it is both single ended and ballanced.  Should be able to get a good used one for around $3000.  Can not do better for the money.
I have a Zesto Leto just like the one listed here on Audiogon. You can run it balanced or single ended. It's not the euphonic tube pre of vintage make but the company makes first rate electronics. The output impedance stays low so a long run to your amp is not a problem. It's on here for $3500 but you may be able to bargain. I have high efficiency speakers and you can turn it all the way up, dead quiet.
I paid a lot more for mine and would buy it again. 
With your budget you can pick at the top of the heap if you are willing to go a little older.  ARC SP-10 or SP-11.  While they are harder to find, there are even CAT SL-1s available in your price range.  I bought a used CAT SL-1 over 25 years ago and have never been tempted to upgrade it.  In all those years I've only had to replace one cap in the power supply.  Ken builds them to last.

Dear vpi:

Tks for your response. One of my friend reminded me that the ARC's SP10 or 11 might have trouble which need maintenance easily. Since I am not a electronic expert, I am a bit afraid to think about having one for consideration of troubles ahead.

The Harmon Kardon Citation 1 preamp is excellent when properly restored. To find one like that would probably be more expensive than the preamps listed, but it can keep up with them easily. A very competent circuit!

The Dyna PAS-3 is not a particularly great preamp, but it lends itself very well to update and modification! I've seen them be giant-killers on many occasions. We've done mods on them for decades and our UV-1 is heavily based on those mods. You can find used PAS-3s for $200-$400 depending on condition- and likely they will need refurbishment at that price.

Our own MP-1 has been in production since 1989. So I guess that can qualify as vintage; it features a direct-coupled output that allows it to be quite transparent; the real issue is whether you can find one.
One Classic pre that I don't believe has been mentioned is the
conrad johnson Premier 3. While its some 30 years old, the sound was excellent when paired with solid state amps.

Another happy owner of a Don Sachs Model 1 6SN7 tube pre!

Don will customize his preamp to ensure it integrates well with your amp, and offers a large choice of upgrade options.

Well worth checking out!
I have heard that ARC drove the tubes really hard in the SP-10 but not so hard in the 11, but do not have personal experience.  For the same money if you are patient you might find a CAT SL-1, with which I have had over 25 years experience.  It's a wonderful preamp with a first rate phono section.  All I've had to do to it is replace one capacitor in the power supply and that only about two years ago.  And I bought mine used.
Happy shunting.
Another good bargain is the Doge 8. Which is about $1500 new. As I said earlier the Linear Tube MicroZotl2 is ridiculously good for the price. Terry London thinks it is outrageously good also and uses it in his reference system. I too had a bias towards older Tube pieces until hearing this preamp. I have had used Supratek, Thor, ARC sp 10, VTL Ultimate, CJ Premier 10, precision fidelity 7a, Doge 8 and others in the budget line all the way to the CJ Art 3 and the ARC Ref 5. The purity of the Linear Tube MicroZotl2 is just amazing. When you roll the tubes it is about as good as it gets. David Berning is obviously a genius! Oh that reminds me that reminds that I had the Berning TF 12 at one time also!
Looking at the listings now there are some awesome choices in your price range such as this:



Just to list a few and many others just above $3K. If you are willing to look beyond the usual suspects, ARC, c-j, etc, there is a wealth of top notch used gear out there in your price range.  I absolutely agree with Swampwalker a good pre is critically important and can really transform the sound of your system!
Don Sachs upgraded my HK C-I and it was splendid, but his own preamp, mentioned above, is far better.  I have had it for a couple of years and with his latest improvements, it is peerless.  There is magic in 6NS7 tubes!!

The thing that always reminds me how subjective this hobby is is the variety of choices we have. I too have owned numerous preamplifiers and heard many times more in my set-up and outside. I am currently enamoured with a Conrad Johnson PV9a that has been upgraded with cutf vcaps bypassing the huge coupling caps, and numerous other upgrades that has taken this preamplifier to another realm altogether. Total investment including purchase price, less than 1.5k including a marvelous phono stage that is just so engaging.The soundstaging, dynamic shadings and timbral accuracy is stunning and an example of what can be accomplished with a well designed vintage product and upgrading parts.

The important thing in considering a vintage unit would include purchase price, condition and cost for upgrading to determine whether or not it is worth it. The big thing to consider is that if you can pick up a good vintage product like a CJ Premier 3, ARC SP8 or a nice 6sn7 based preamp with a good power supply, much can be done to improve performance and it sure can be worth it. I know a few guys that still use Marantz 7 preamps. Good design is timeless and better parts can realize significant improvements.  

@tubegroover , just FWIW, bypassing an existing coupling cap is often a bad idea. I don't doubt that you enjoy how the unit sounds now, but I strongly suspect that if you had cutf V-Caps of the correct value as used in the stock cj that it would sound even better. It is often the case that bypassing coupling caps can result in smearing (especially at higher frequencies); for this reason it usually seems best to give the coupling caps your best shot with a single part.
The problem is how to keep good maintenance of the vintage gears.  Some parts are hard to find, some changes might change your sound reproductions. Also, judging on it's rare quantity, it is hard to find the right, experienced, dedicated engineer to fix it.  
Ralph I have no doubt that having the correct value caps would be ideal however I’m not even sure that Vcap makes the cutf capacitors of the value required, 20uF X 4. In any case the cost would be prohibitive if they do which I don’t see on their web site. If there is any smearing relative to the stock polystyrene caps, it isn’t evident to me and as stated, there was significant overall improvement along with numerous other upgrades by Bill Thalmann.

Conrad Johnson has a teflon cap upgrade but if I spent what they were asking for their upgrades one might question the sanity of going that route, it sure didn't make sense to me.
Just received my Linear Tube MicroZOTL2 and it is stunner as a preamp right out of the box! Anyone looking for a preamp under $2,000 should give this a listen because it is amazing. It also responds to Tube rolling. I immediately put Tungsol Round plate 6sn7's in it and it plays music better than anything else I have ever heard! It only has three inputs and the remote will only adjust volume, but this piece is one of the great bargains in audio. I have heard most of the preamps in this thread and my opinion this is the best of the bunch! The tonality and imaging of this preamp (headphone amp actually) is just spot on. You really don't need to spend any more for world class performance. I want to give a shout out to Teajay who first introduced me to this preamp.
@tubegroover , are these caps at the output of the preamp? If so, what sort of amp are they driving?

A very common issue that faces preamp manufacturers is the value of the output coupling cap. This is often defined by the lowest impedance that the unit is expected to drive (and certainly is a dilemma as smaller caps almost always sound better than large ones). But if you are driving a tube amp the caps might not have to be so large! Just a thought- its easy enough to calculate the right value given the input impedance of the amplifier...
Yes Ralph, the caps are at the output driving a pair of Quicksilver amps with an input impedance of 100K. I also have used with a pair of vintage MC60's and  a Berning zotl amp to equally good effect.
For the money buy an old counterpoint SA-2000 and send it to me for upgrading.  Volume control, caps, new resistors, I will incorporate tube rectification, etc.  Should beat the ARC ref II preamp and a few others.

Happy Listening.