12ax7's to roll

Your Sylvanias are good tubes and you may have trouble finding something that you prefer.

Telefunkens are considered to be the ultimate neutral, detailed NOS (and very long lived). Amperex are reputed to have the best, most natural midrange. Mullard are considered warm and less detailed. These are all generalizations which may not be true in your system.

I would do a search for tube dealers and talk to one of the good ones about what changes you would like to hear from a new set of tubes. A good dealer's experience is invaluable as tube rolling can be an expensive crapshoot.

If you like what you have save your money and take your kids out for Pizza!!! Telefunkens are not for everyone..Keep the Sylvanias and enjoy the music...

I agree with Tomcy6. Have a look at this : http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html

If you are satisfied with the actual sound of the Rogue, you don't have to go for the most expensive tubes simply because you are curious.

I personnally tried many combinations, especially with 5751 tubes (alternative to 12AX7) recommended in the above mentioned review and had a lot of fun. For instance, it is still possible to get NOS 5751s from the 50's, black plated 3 micas for low noise at 60-80 $ a pair.

Regards !

Though I've not extensive first hand exp with Tele v other 12AX7's, I'd say the RCA & Tele's are very close in character to one another. One main USA tube vendor personally told me their diffs were very slight, meaning to me unless one has a very resolvling rig, they likely won't notice the diffs.

I've been reasonably well pleased using RCA tubes in several preamp or amp selections. In comnbination with Tungsols, Matsushita, & Amperex Bugle boys.

I've also found that several makes of tubes have a particular voice of their own generally speaking. Amperex's are bold and up front tubes, with all the audiophile needs being addressed. RCA as was posted are more subdued or reserved in terms of detail leaning towards the warmer side of the border. Tungsols resemble the Amperex's like Rotel emulates the Krell... but for less 4$$. tele's have great mids and top ends but their bass is not their strengths.

tastes, combinations of these, the gear too, can and will provide your audio system with many hours of interesting outcomes as you plug in and out various sorts.

you can also try buying some used ones and see for yourself what's up with who, for a bit less dough than buying reputedly new old stockers.

The tube vendor's rep and/or the seller's rep, is more important than the tube in question. you certainly don't want to buy tubes with issues or nearing the end of their cycle... or noisey & microfonic.

Good luck.

Great info and thank you all for the replies. I'm going to take my time and talk to some of the dealers as recommended.

Do 12ax7 / 12au7's last 10,000 hours? I thought I read that somewhere. I have this fear of having a tube go on a Friday night resulting in no music. I purchased a new matched quad of Electro Harmonix KT90's from Rogue just in case.

The Rogue tamed those speakers, correct? I hope you can enjoy the music now. I had good luck with Gold Lion KT-77s if you want different tubes down the road.

I was very surprised with the performance of new Electro Harmonic 12ax7 Gold Pins (not NOS): dynamic and accurate. They were $35.00 for the pair. I like Siemens 12ax7s, very accurate and quiet and I liked them more than Telefunkens

1950s RCA Black plates....Raytheon long plates..Sylvania long plates..all great tubes.Much cheaper and out perform the overhyped Tele tubes IMO

Some Telefunekin wantabe's - EI 12AX7E (long grey plate). No longer manufactured as EI is out of business but they can be found. An excellent and balanced sound. The only reservation I have is that they could be microphonic in a sensitive (i.e. a phono stage)location. I use them a lot. I bought from a dealer in England and the last time I was on the their site they still had them listed.

For warmer sounding 12AX7s, I like Amperex Bugle Boys. It could be just a synergy issue, but, Mullards do not sound that good in my Viva Fono phonostage, and they sounded oddly phasey in a friends Tron phonostage.

Telefunkens and the one set of RCA tubes I have are on the leaner, clearer and more dynamic side. The most dynamic and exciting sounding 12AX7, to me, is the ECC803S. This tube is, however, insanely expensive and it could be too lean sounding for many applications. This is the tube I use in my phonostage (I am counting on its reputation for being extremely durable).

I really like the 5751s I've tried, though they may not be suitable drop in replacements for 12AX7 (they deliver lower gain than a 12AX7).

I agree with Andr 5751's would be the closest to the tele's clean detailed sound at reasonable $'s. The 5751 is a very low noise tube,less gain than 12AX7, but if your preamp has plenty of gain you will be OK.

5751s are a great experiments, and make serious committments once done. As mentioned not too much $$.

I liked the Sylvanias in my Magnum, but swapped the 12ax7s out for Tungsol 5751s and the 12 au7s with RFTs (similiar in sound to RCAs to my ears) overall a little warmer sound than the Sylvania's . Here's a link to Brent Jesse's 12ax7 &12 au7 web pages (I am only a customer) gives some isnight on different tubes - easy guy to talk to as well

http://www.audiotubes.com/12ax7.htm
http://www.audiotubes.com/12au7.htm

I second the Ei 12AX7 suggestion. The older Ei's, with the white lettering are the ticket. FWIW, I am currently using a pair with a CAL Alpha, and I prefer them to NOS GE 5751 that cost a lot more $$. I may be mistaken, but I think Ei is still in business. I have a pair of (I believe) current production Ei 12X7 Gold Pin Elites, but they don't sound as good as the older ones.

Amperex or Mullards. 5751 has a rated gain of 70, while a 12AX7 is rated at 100. You may not want to reduce the gain.

The "Best" all depends on the circuit it is being used in. I like the Amperex "60's" version best, but also like Telefunkens, but some are a bit bright, the Mullards are very warm, but good for many circuits. Those are the big 3 at the top of the food chain IMHO. Next come the Sylvanias, GE's, and Ei white lettering, and falling in line after that is the other EH, Sovtek's, and some of the Chinese 12AX7's are a surprise. Unfortunately, you may need 10 to get a good one. You really need a few of all of them to play. If you are really wanting the good ones, get the Bugle Boys of the 50's. Just be ready to part with a few big coins. 150-300ea. depending on the vintage and supply which is getting smaller. jallen

Some 12AX7 and 12AU7s can last up to 10,000 hours. As has been said, Telefunkens are known for long life. Some tubes were advertised as 10,000 hour tubes such as the Mullard 10M line. I think that 3-5,000 hours is more realistic.

Small signal tubes, like any tube, can conk out at any time. Most won't though. They more often become noisy or microphonic. That's part of the crapshoot. It's always a good idea to have a spare set of tubes in case this happens. A good dealer can advise you on this topic as well.

As other's have posted here, and I'm appreciative of their comments, each tube make and vintage will usually supply a different flavor.

As for hours? outside of the Amperex & tungsol tubes rolling in new ones every other year of usage is a very nice thing. Not necessarily a needed thing, just a nice thing. Fresh tubes from a great vendor whose abilities to test thoroughly each tube sold is imperitive. i'm not keen on Audio tubes, formerly Brent Jessie tubes... BTW, Why the name change?

FYI ... His return policy bares greater investigation.

Andy Bowman of VINTAGE TUBES isn't the cheapest place to buy tubes, but I've never had to return any to him either. that's very important. Very. I'm sure too, if one did fail outright soon after receipt Andy would take care of it. Great guy, and excellent products.

Superwolf. Yes, the Rogue did tame the speakers. Enough so that I don't even recognize them anymore. It's so nice to not have to worry about it any longer. Now I'm able to enjoy listening and researching new music.

Somec59. Your post made me very happy. To know that someone prefers tubes that cost $35/pair more than NOS tubes at $200/pair is very exciting indeed.

I really appreciate the information you have all provided me. I'm also thankful for this website. I don't think I'd be enjoying music the way I am right now if it wasn't for this forum. Just 6 months ago I preferred to listen to music in my 4 Runner over my brand new amp/preamp. I never imagined being able to cure all my problems with one web site.

Donjr: The 35.00 cost for a pair of new ElectroHarmonic 12ax7 tubes covers the cost of manufacturing and distributing at 2009 prices. At times I've bought expensive NOS tubes which invariably helped maintain the high prices of NOS tubes. There are costs involved with finding, buying and shipping NOS tubes and providing a luxury service to me, but I would like to know what a pair of Tele's or Mullards cost 40-50 years ago.