6SN7 driver tubes

I need to replace a few 6SN7 drivers in my amps. They take 3 per side. I've been using Sylvania 6SN7GTB which sound great, but they're pricey to find reliable ones. I've been considering EH or Chinese brown base. Any thoughts on these? Or any other recommendations? I want to keep the cost under $20 per tube.
For 20 per tube, try the Tungsol 6SN7 reissue
If you have been using nos Sylvania's and like the sound,I doubt very seriously that you will be happy with new chinese or russian tubes.I have found the ones I have used(EH,JJ,Ruby,etc.)to have a profound "glare" to the sound.Then again,they might sound just fine to you,you'll never know unless you try them.
In my Modwright Transporter, I have found the Russian 1960's Vintage 6H8C/6SN7 from UpscaleAudio.com work terrifically. Nearly on par with Tung Sol 6SN7GT round plates. In fact, I sold my TS round plates after installing the Russian 6H8C, and I have absolutely no regrets.
I wrote an assay wich went somewhere. The upshot is . IMHO the Sylvanias are my favorites especially the chrome heavy T plates that are directly opposed with 3 rivets.
Brent Jesse of AudioTubes.com can set you up with true NOS tubes for $20 each,or thereabouts anyway. In your price range.
Usually RCA and sometimes later GE niether of which are that great.He may have some OEM Philco or Admiral etc. Sylvania true chrome dome, top getter, T plates,however. They excell in balanced extension and are a great 3D sound staging tubes.
I have heard that the russian tube is a world beater, but only the real deal old stock tubes. I have also heard their noise floor tends to be high. With drivers that usually doesn't matter. The tube you choose though, will alter the sound even in the driver spot.
If you go for the Russian tube be careful who you buy them from. The seller should know what he is doing and know the other choices.
If you send me an email I will give you a long list of what I think the outstanding attributes are,for the various commonly encountered 6SN7s.
09-21-09: Mechans
I have heard that the russian tube is a world beater, but only the real deal old stock tubes. I have also heard their noise floor tends to be high.

What I hear with my own ears when used in the analog output section of the Modwright Transporter, is that the Russian 6H8C are absolutely dead quiet. No noise issue whatsoever. They are the "Platinum" grade tubes from UpscaleAudio. $25/ea. Perhaps they are noisy in a higher gain application, but I suspect *any* tube would be relatively noisier in a higher gain application (e.g. MC phono preamp).

I suggest calling Kevin Deal, and asking him for his recommendation based on your specific amplifier. He may have some other ideas as well.
Tvad, how would describe the sound of the Russian 6H8C?
It's a pretty neutral tube, IMO.

The highs are extended without etch. The bass is balanced and detailed. The Russian tube may have just a slight more midrange bloom than the TS round plates, but not significantly so. I do find the image to be larger with the Russian tubes than with the Tung Sol round plates (which I generally regard as the benchmark 6SN7).
Ditto recommendation of Tung Sol 6SN7 reissue. They get pretty close to the good characteristics of NOS Russian 1578.
I have always used EH 6SN7 tubesin all my Cary amps and preamps w/ excellent results for not much doe. They are nicely balance and great frequency extension. They last a really long time, as I've never had one go bad. They do take a long time to break in before they really sound fluid.
I just looked at your system and see you are using the DJH preamp. I had that premp and the Chinese tubes Cary used sound really musical, smooth, and big (but with a diffused soundstage). The EH in the place of the Chinese had much better detail and frequency extension. They will sound a bit harsh until they break in.

With this preamp you never have to, or never should turn it off. It will sound better and the tubes last forever in it. This is Cary's recommendation, not my own, and my experience confirms this.
I appreciate all the feedback and suggestions. Thank you!