Two of the best tubes are Mullard M8162 gold pin which is a military version of the Mullard 12AT7. Also the standard Telefunken 12AT7 and the long life 10 K hour Telefunken 801S. The 801S is very expensive, the Mullard is available in matched pairs for about $42.00 each.
I have tried several types of 12AT7's in my VTL 750 amps, including the factory versions, and in my opinion most aftermarket (old) NOS are superior that what was supplied by VTL.
Very generally speaking, if you want the most midrange detail possible, go for the Telefunken. If you want a warm relaxed midrange and bass with slightly soft high frequencies the Mullard is your best bet.
Please understand too, my comments about sound differences are magnified in my description to differentiate between these tubes. Real world, both are superior to the JJ and would likely make you happy.
Let us know what you choose if you do a shoot out.
i am using rca black plate 12at7 with my vtl deluxe 120 amps.
another suggestion is to use tube dampers on the 12at7. i use EAT tube dampers.
I guess I'll throw in another 12at7,which I liked better in my sytem than the mentioned tubes by Albert. I tried the Mullards and both the Telefunkens ( ecc81 and 801s ) and prefered the Amperex 12at7 Bugle boy ( holland or france ).I found that the Bugle Boys are better balanced all around.Of course this is in my system.. Good luck
The RCA Black plates are worth considering as well. Eventually I preferred the Telefunken sound. Good Luck! Bill.
As an alternative to the expensive telefunken tubes, you can try the Siemens 12at7, I liked them when I use to have an AVA preamp.
There is no need to stay with the JJs. I have a bunch of 12AT7s except the truly expensive and rare they all have their own sound, Start rolling.
I'm not all that familiar with 12AT7 types, but one not previously mentioned is the Sylvania Gold Brand 6201. I use a pair of these in my Lector CDP 0.6T and they work very well for that application although I've not made any comparisons between Sylvanias and other types. Worth looking into.
I am using Sylvania Gold Brand 6201 in the phono section of my VTL TL 5.5 with excellent results. I also tried Mullard CV4024 with very good results. I currently use the Mullards in my VTL ST150. Between the these two tubes I liked the Sylvania just a little better. The Sylvaias have a more pronounced but at the same time better controlled bass than the Mullards. Other than that I like them equally well.
Both were much better than the stock tubes.
Easytune: You wrote that you need to replace "one tube" in the phonostage. Do you mean by that literally a single tube? I mention this only because most phonostage circuits use L/R pairs of matched tubes, and you wouldn't replace one without replacing the pair with the same choice, tested and matched for gain. As for your question about the Mullards, the wisdom I've received is that in general, the earlier you go in manufacture date, the darker they will sound, whereas the Tele's are said to be pretty consistent throughout. I've tried versions of the Mullards, Teles, RCAs and Sylvanias, and they all sound different, but my best advice to you, with a phonostage (where quietness is at an absolute premium), is to make sure you're dealing with someone who can really test and vouch for his tubes' freedom from incipient noise and microphony issues, and will stand behind them if an audible problem develops within a reasonable period of time.
For a detailed (read exhaustive) description of the various 12AT7s, try Joes Tube Lore over at the Asylum.
First , thanks everyone for all inputs,advice and recommendations. I have bought siemens tube,and planned to get amperex one. I would love to get Telefunken ,mullard ,RCA tubes when opportunities come. I would post my impressions from tubes i bought.
My VTL tp2.5 phono stage uses 1 single 12at7 and 3 12ax7 tubes.I broke 12at1 one when i clamped mapleshade tube anchor with it. Do I need to match my new single 12at7 tube with old 12ax7 ones for the gain? Thanks for your advice.KB
The gain factor is constant for a 12AT7. The age of the tube can be a factor in dissipation but it's only noticible if you have a brand new or near dead tube. Is that what you meant about matching it to the 12AX7s. Go to the Tubestore.com and use their gain factor chart. Or did you mean matching channels in that case both should be very closely matched and the same tubes. I don't get it? You don't need to match the the 12AX7s.
How does the EI fall into this group? They came stock with my stingray. Another member has a set of teles Im interesting in.
EIs are not bad sounding tubes. No-one seems to have mentioned the Electro Harmonix tube either, although if pcied for low microphonics, is a very nice sounding tube, even if it is a newly manufactered tube.
Often the Chinese 12AT7 gets denigrated in discussions like this, but I thought it important to point some things out about them: They are very quiet- the most consistant that we have tested. In a phono section this can be a big deal. If also hand-picked for low microphonics, they can rival the sonics of NOS tubes quite easily. One time Albert shipped us his amplifiers, which had Telefunken 12AT7s in it, and we replaced them with the Chinese tube. To our surprise, the Chinese sounded a lot better! We then tested the Telefunken tubes and found that they were testing in the '?' range of the tube tester. Since then we have seen quite a few good-testing Mullards, Siemans and Amperex that got dusted by the lowly Chinese tube...
One thing is for sure- its to your best interest to make sure you are installing a good tube! Make sure that whatever you get can be returned if you are not satisfied!
Mullards are the best I have heard... Can change systems from nice to incredible.. Most of the time the gear is beyond the quality of the tube used in it and you would never need a 15 k piece of gear, just some real good and silent musical tubes out of the norm.
"Mullards are the best I have heard... Can change systems from nice to incredible"
Undertow, what's your definition of incredible? I ask because tube rolling seems to be a way for people to get the sound they "want". I have an AVA FetValve 550, which also uses the 12AT7. Frank van Alstine ships these amps with JJs and is quite insistent on using these tubes. I tried Ei and also borrowed a pair of Mullards, and found that (to my ears) Frank was right. Of course, all that may mean is that Frank and I agree on what the "right" sound is for that amp. I found the JJ 12AT7 to have the least "tube like" characteristics of the ones I tried. My goal is to not hear anything that would tell me that I'm listening to either tubes or SS (FetValve is a hybrid).
Well I guess exactly what you said, they sound warmer which counteracts the steril newer stuff most the time. Very detailed, deep quiet, bass is all there.. And they normally run dead silent in comparison to all other tubes I have had.. Yes JJ's actually are one of the better new tubes, I had them and found them nice, they hummed a little, most of the mullards were a little pricey and matched, tested for microphonics and were all dead silent, literally with 101 db efficient speakers you would never know the units were on they are that dead quiet and always sound smooth,even in 60 db phono stages. Don't take as long to burn in, faster to warm up and sound right, normally about 20 mins and they are at most of the peak after about 50 hours first. Maybe I just like the character and consistent quality of the mullards, others have always given me problems and not always sounded the way I like. Thats all I can explain, however don't take my word, many, many people will consider mullards especially in the 12 series tubes some of the best, but maybe not if they don't work for you. Its up to you to try.
It takes all kinds, I guess. I've been living with all SS gear for the last 20 or so years (good stuff, though, not like a lot of the bleached stuff that you find a lot in the SS world). But with my move to the FetValve, and a Pass X1 preamp (which is not classically SS by any means) I've tried to find a good balance between these two worlds. So far the JJs do it for me, but if I run across a chance to get a nice pair of Mullards I may try them again.
Some of the recent JJs have been a bit hummy. If you have a circuit that has DC filaments they are a decent tube otherwise.
I've tried a lot of 12AT7s:
Siemens E81CC- 3 mica- NOS
Siemens ECC81- NOS
Valvo 6201- GP- Hamburg- NOS
Mullard M8162 NOS
Sylvania GB 6201-steel pin NOS
Sylvania GB 6201- gold pins- NOS
Amperex Bugle Boy-France- NOS
GE 6201 5 star- 3-mica NOS
RCA -HP- NOS
RCA 6201 2-mica black plate- NOS
Sylvania JAN 12AT7WA 3-mica 1958 -NOS
Sylvania 12AT7WA-Gold Print- 3 mica -USED
Westinghouse- black plate-NOS
Telefunken ECC81- USED
Philips JAN- NEW
GE 6201- 3 mica, sq gtr- NOS
Telefunken ECC81- NOS
Telefunken ECC801S- NOS
The 12AT7 makes a surprising contribution to the sound of the 6 pieces of tube gear I use it in and I've played with this type more than most others.
I would characterise it by first suggesting the two 'extremes' of sound I found. The triple mica Siemens is clean, fast, punchy, and lively- detailed and deep. On the other end is the Sylvania 12AT7WA. These are triple mica late 50's tubes that are almost impossibly lush and deep, still detailed but more 'forgiving' than the Siemens. For some reason, Sylvania really got the 12AT7 right and the suggestion for the Gold-Brand 6201 is a good one. In the middle are the various Philips models and the one I would suggest for VTL would be the Philips 6201- gold pin. These can be made by Philips Holland or Germany. I'm using a pair of Hamburg ones (from seller 'tubemonger' who sells on Audiogon sometimes) in my microphone preamp and I find these to be balanced, have great frequency extension and are smooth, quiet and great detail.
The Telefunken ECC801S mentioned elsewhere is a nice one too, but it has a speical sound- a bit 'delicate' that I think might be too specific a type just to experiment with- and they can be quite expensive now. Mullards too are also a bit specific to the midrange, but can be very nice. I agree with the poster that the M8162 is fantastic. If you try the M8162, there are several versions, and the older the better. If you're wealthy ($50-60 each), there is the ultimate 12AT7, the Valvo, Hamburg, pinched waist blue label 6201.
It may be that as an Audio Research user, I gravitate towards the faster, more neutral tubes- and I find I just never dislike Siemens tubes. If you find the VTL to be a bit soft, the Siemens E81CC can wake it up a bit- and that's what I use in my old McIntosh stuff too. If you want what I call the 'Bing Crosby 1939' sound- it's the Sylvania. With Siemens, always be sure they're 'Siemens and Halske'- with the little intertwinned 'S&H' and not the later two mica versions with just "SIEMENS' in big block letters. One slightly eccentric idea is the old square-getter triple mica GE 6201- these have a great bass and are quiet, detailed, and rugged. The nice feature of this one- I just bought the GE NOS a couple of months ago for $8 each. This is the tube I plan to use as 12AT7 in my power amps and Audio Research SP10 power supply. The normal GE 12AT7 is a mediocre one, but this old 6201 is a 'sleeper' in my view.
Overall, I'd begin with Philips, Hamburg 6201. The gold pin Valvo, Hamburg 6201 will be the same tube and sometimes less expensive.