12ax7 upgrade recommendations

[IanTY]

Hi, I've just ordered a Pro-Ject Tube Box II phono pre-amp. I am thinking to the future for possible 12AX7 upgrades. Turntable is a Systemdek IIX with a Jelco arm and DL-103 cart. BTW, what are the "Pro-Ject" branded 12ax7's?

Can anyone recommend both new and NOS tubes for me to keep an eye out for that would be suitable for this phono pre-amp. Many thanks. - Ian.

[GordonW]

I haven 't gotten a straight answer from anyone... but my guess on the origin of the tubes in the Pro-Ject Tube Box is probably either EI or Tesla, or something similar. I'd expect them to source tubes locally to them... somewhere in eastern Europe...

Regards,
Gordon.

[markus]

best thing to do is get a good cross-section of 'well-regarded' 12ax7's, roll 'em in circuit, and see which you like best . . .

telefunken, amperex, rca, GE, mullard . . . . everyone has their favorite flavor . . . there's also the 7025, which is a 'low noise' 12AX7 . . . might be worth checking out since it's a phono stage. I know at least the big US tube companies made them (RCA, Sylvania, GE). . .

sometimes you can find people selling mixed bags of 12ax7's on 'the Bay' for this express purpose.

I'll take vintage tubes over new production any day of the week :yes:

[Jack G]

You can also try 5751s. Slightly less gain, but work well as a 12AX7 sub. With the possible exception of the generic GE gray plates (only mediocre), they sound very good.
Jack

[jmathers]

As far as new production, you may want to try these:

Sovtek 12ax7LPS
TungSol 12ax7
Mullard Reissue 12ax7

I'd also recommend the Groove Tubes 12ax7M tube but there's been some decline in quality in the past year or so.

The above tubes are decent tubes and far cheaper than NOS. Worth a try IMO.

Jeff

[sorenj07]

You should also try some Russian 6N2P's just for fun, they're cheap.

[gearhound]

I've used NOS Sylvania 5751 tubes with good results.

Steve

[hammr7]

If you never push your system (in terms of ultimate output volume) you might be able to try 12AU7s. You take a hit in gain, and therefor ultimate volume (5+ dB) for a given output setting. But old stock 12AU7s are often reasonably priced and most are dead quiet. Thats one reason why so many old tube organs settled on 12AU7s in their tone cabinets. On the flip side, many guitarists use older tube amps where 12AU7s and 12AX7s can be used interchangeably. But they avoid many of the 12AU7s because they can't get them to distort the way the 12AX7s will.

[BrassTeacher]

If you want great-sounding NOS, or strong used tubes, look for Mullards, from the Blackburn plant. The second line of the "date code" (a misnomer for Mullards) will begin with a "B"

Why a misnomer for "date code"? The so-called date code on an older Mullard tube tells you what type the tube is and which plant it was produced in, as well as the date. In other words, there's a lot more info there than which week of what year it was made. The Mullard date code tells you the month and the year, but not which week.

I'm using a pair of used, but strong testing Blackburn Mullards in the phono stage of my modified Counterpoint SA-1000 preamp, and the sound is stunning!

[zenith2134]

My JJ 12ax7s sound pretty darn good in my integrated's phono section. No issue after a few months of regular usage. NOS is better though I hear

[Mr. Lin]

Hi, I've just ordered a Pro-Ject Tube Box II phono pre-amp. I am thinking to the future for possible 12AX7 upgrades. Turntable is a Systemdek IIX with a Jelco arm and DL-103 cart. BTW, what are the "Pro-Ject" branded 12ax7's?

Can anyone recommend both new and NOS tubes for me to keep an eye out for that would be suitable for this phono pre-amp. Many thanks. - Ian.

Ian, I have a Tube Box II, although it's currently on standby because I've upgraded. It's a very good phono preamp and it got me really interested in tubes. It was also the first good phono preamp I owned, and I was thrilled at how much better everything sounded in my turntable system when I hooked it up.

The Pro-Ject branded tubes that it comes with are Electro Harmonix - I compared them and they're 100% identical in every way. While it will sound good out of the box, the EH tubes are hardly going to show you the best of what the Tube Box II has to offer.

When I began tube rolling I first tried Sovteks, which to me sounded like a real upgrade from the stock tubes. I then went through several new models of tubes and found the JJ Tesla to be without question the best-sounding in my system.

If you want the best you'll have to pay for NOS, which can be quite expensive. I wasn't thrilled with Telefunken 12AX7s (yes they are genuine) even though they're a very popular tube. Mullard worked quite well, as did Sylvania (a softer, warmer sound that brought out the midrange a bit, and less expensive than many NOS tubes), and GE 5751s like some recommended here - they're good with this preamp but there's less gain.

Unfortunately I have to tell you the very best were in fact the most expensive, many of which I bought from Upscale Audio, which has some amazing tubes, but you will pay big time because they're all rare, thoroughly tested and definitely never used. A pair of Holland-made Philips with dimple pan getters were amazing, especially in the higher frequencies, and there was improved resolution. The absolute best was the Pope 12AX7, which is apparently the exact same thing as the infamous and highly sought after Amperex Bugle Boy. When I bought them they were around $125 a pop, which is far more than most people can or would spend on tubes, but in every category they are phenomenal, and also the most neutral-sounding of any 12AX7 tube I've heard. I think the price has since increased because they're probably running low on these, and I think they're quite rare.

La Radiotechnique is a lesser-known French brand, so these are not always quite as expensive, but I highly recommend them. Very good imaging, solid all around.

I hope this helps a little. Remember that tubes are circuit and system dependent, so what I've told you might still not be your experience since we're only talking about the same circuit, and we have different systems.

I'd really like to hear your impressions once you get the Tube Box II, and of course once you start tube rolling.

Dave

[Tube Radio]

I use TAD 12AX7 tubes in my Scott LK-72A and I like the sound of them. Very balanced IMHO.

[goraman]

As far as new production, you may want to try these:

Sovtek 12ax7LPS
TungSol 12ax7
Mullard Reissue 12ax7

I'd also recommend the Groove Tubes 12ax7M tube but there's been some decline in quality in the past year or so.

The above tubes are decent tubes and far cheaper than NOS. Worth a try IMO.

Jeff
This is the best list of new but Id put the Tung sol at the bottom of it as the Sovtek LPS is said to be the most dynamic of all 3 and haveing rolled all 3 latley in my little Bellari single tube along with an Ei silver long plate,I found my self removeing the tung sol,as it had a hell of a lot of gain,importaint in a single tube but not the most importaint it had big bass and trebble but weak mids,Not to bad because I'm am useing a Grado Gold and Ei pre amp tubes and Tad EL 84 driver tubes all midrange strong,the Ei's gave great highs and mids but lacked bass,the Mullerd gave me all three but laid there uninvolving luke warm boreing,the sovtek lps long plate spiral screen is fun and engaging bass ,mids and highs are all pretty even here and not microfonic like the Ei .
If money is no object 1950 to 1964 (west german) Telefunkens or Amprex Bugal boys(Holland made not France) or pre 1970's Mullards.

[IanTY]

Awesome responses, many thanks to all for taking the time. Mr. Lin. I will indeed try to post my findings once I get it warmed through. It arrives Wednesday. Sorry I'm late responding to this post as I've spent all night assessing two Reel to Reel decks. One or the other will be used for spares. Akai 1722MKII and an Akai GX4000. Trying to make one good deck from the two. The 4000 is looking promising even though it has the higher milage of the two.

Once again many thanks. I'll re-read the post tomorrow to try to take it all in. - Ian.

[pilotputz]

IanTY,
Some pretty good 12ax7 suggestions have been given in this post. I would simply add the Raytheon black plates and the Sylvania black plates to the list of 12ax7s that you should try. The 1950s American black plates have a very rich and lush sound to them.

[dividebytube]

budget 12AX7s : the Shuguang 12AX7C9 is very warm sound, the Sovtek 12AX7LPS is very good too. Also be on the lookout for Matsushita and Toshiba 12AX7s - very well made and quiet too.

Through Ebay I've also bought Westinghouse tubes which are usually (but not always) relabeled RCAs. Also be on the lookout for Fisher/Dynaco/etc labeled tubes as these can often be Telefunkens, Mullards, or whatever.

[Beanstocks]

Through my Eico HF 85 phono stage Tele smooth plates sound great with much detail; Mullard Gr. Britain old stock very warm and smooth; Amperex Bugle Boys the best so far with rich detailed involving instruments and vocals. The saxophone moved right in front of me where it felt I could bend over and look into that spout. Ben Webster never sounded so good. Hope that helps.

[roggae]

best thing to do is get a good cross-section of 'well-regarded' 12ax7's, roll 'em in circuit, and see which you like best . . .

telefunken, amperex, rca, GE, mullard . . . . everyone has their favorite flavor . . . there's also the 7025, which is a 'low noise' 12AX7 . . . might be worth checking out since it's a phono stage. I know at least the big US tube companies made them (RCA, Sylvania, GE). . .

sometimes you can find people selling mixed bags of 12ax7's on 'the Bay' for this express purpose.

I'll take vintage tubes over new production any day of the week :yes:


is there somewhere in particular one can go to read about these 'flavors'?

[goraman]

I just rolled some 1950 Standard Brand RCA 12AT7's short black plates into the pre stage of the Manley Stingray and WOW! are they dreamey.(NOS)

[DENNYDOG]

is there somewhere in particular one can go to read about these 'flavors'?

You are there already.

[Stewie]

is there somewhere in particular one can go to read about these 'flavors'?

I found this very helpful--don't know if anyone's mentioned it yet.

http://www.audioasylum.com/audio/faq/joes-tubes.html

To the fine recommendations you've gotten thus far, I'd add the Sylvania Gold Brand Gold pins. What they say about the mid-range on these tubes is true, at least in my Jolida 100a. As has been pointed out, everything is system-dependent, but I do find that Joe's Lore helps you pinpoint where you might look if there's something in your system you'd like to emphasize.

[markus]

is there somewhere in particular one can go to read about these 'flavors'?

well . .. thats the pisser .. . the flavor all depends on what you're 'cooking' them in . . .

a telefunken in a fisher preamp stage is probably gonna sound different then in a magnavox console amp . . .

I admit I DO NOT have golden ears - I've rolled tubes in a number amps, and I think the only audible difference is how strong the tube is. A new, or near-new tube sounds better than a high mileage tube . . .

SO MUCH of the tube sound, and audio in general is 'system / chain' dependant . . . speakers, amps, source . . . when you start climbing towards the audio stratosphere, every little thing makes a difference. Hell - there's guys that develop systems around a single TUBE to maximize the sound.

if you want to really tweak over tube sonics, you really need to hit the Tube Forum at Audiuo Asylum . . . of course, the funny thing is, if you go to the Antique Radios Forum (http://www.antiqueradios.com/forums/index.php) they get a kick out of guys who quibble over this . . . they view a tube as an appliance - just something to do a job - who argues over what brand lightbulb shines better after all ?

I dunno . . . tubes do their job, and look great doing it. better than staring at a transistor :yes: I guess if I ever throw together a 'ultra-fi' optimized system I can argue subtle points of tube sonics . .. till then, I'll just listen to the music :music:

[Mr. Lin]

I found this very helpful--don't know if anyone's mentioned it yet.

http://www.audioasylum.com/audio/faq/joes-tubes.html

To the fine recommendations you've gotten thus far, I'd add the Sylvania Gold Brand Gold pins. What they say about the mid-range on these tubes is true, at least in my Jolida 100a. As has been pointed out, everything is system-dependent, but I do find that Joe's Lore helps you pinpoint where you might look if there's something in your system you'd like to emphasize.

I've read that before, and I don't agree with a lot of what this guy has to say about the 12AX7/12AU7, largely because he makes the broad generalization that they're pretty much all bad, which very many people would disagree with.

[IanTY]

Quick update. If forgot to mention (not that it matters) that this amp is the Pro-Ject Tube Box II SE. Not the basic version I was originally going to order.

The tubes in it are Tung-Sol 12AX7. Or at least that is what they look like (99% visual match). They have circular heat-syncs (finned) glued to them so I can't completely see the design. I pulled one out and had a pretty good look at it.

I'll be giving something akin to a review later when I've spent more time with it and before I start rolling. In the mean time, two questions. Can I use 5751 tubes in this design? I'm dying to try some. And secondly, since it came with radial alloy finned heat-syncs on the tubes, should I use them on any tubes I roll through it? Many thanks - Ian.

[Mr. Lin]

Quick update. If forgot to mention (not that it matters) that this amp is the Pro-Ject Tube Box II SE. Not the basic version I was originally going to order.

The tubes in it are Tung-Sol 12AX7. Or at least that is what they look like (99% visual match). They have circular heat-syncs (finned) glued to them so I can't completely see the design. I pulled one out and had a pretty good look at it.

I'll be giving something akin to a review later when I've spent more time with it and before I start rolling. In the mean time, two questions. Can I use 5751 tubes in this design? I'm dying to try some. And secondly, since it came with radial alloy finned heat-syncs on the tubes, should I use them on any tubes I roll through it? Many thanks - Ian.

By heat sinks do you mean dampers that actually wrap around the tubes? If that's the case you might as well use them, but you could try them without to see if it sounds better. If they're actually just heat sinks, and their purpose is to keep the tubes cool (it's an enclosed case design, right?), you should probably always use them.

And yes, you can use 5751 tubes, but remember what some people here said: There's less gain than 12AX7, and it could throw off the RIAA equalization curve.

[IanTY]

Dave, they are not dampers, definitely heat-syncs. I should have photographed them when I had them out. The cabinet is not closed, it has two holes at the back for the 12AX7's to pop through. You can only see the tops of the tubes (getter flash). The holes are just big enough to pull out the tube with it's resident heat-sync ring intact (which is handy, since it is glued on). Considering the unit is essentially a pre-amp, I find it runs pretty hot once it has soaked for a few hours. Find a photo of the Pro-Ject Tube Box SE II, and you'll have a better idea, and I'll photograph the syncs when I get chance - they're pretty cool and I'd like to find some for my next tubes.- Ian.

[paul cbc]

Early 90's Ei 12AX7-sound very close to Telefunkens.
Sovtek 12AX7LPS-when well screened(good supplier) are a very quiet tube.

Paul

[Mr. Lin]

Dave, they are not dampers, definitely heat-syncs. I should have photographed them when I had them out. The cabinet is not closed, it has two holes at the back for the 12AX7's to pop through. You can only see the tops of the tubes (getter flash). The holes are just big enough to pull out the tube with it's resident heat-sync ring intact (which is handy, since it is glued on). Considering the unit is essentially a pre-amp, I find it runs pretty hot once it has soaked for a few hours. Find a photo of the Pro-Ject Tube Box SE II, and you'll have a better idea, and I'll photograph the syncs when I get chance - they're pretty cool and I'd like to find some for my next tubes.- Ian.

OK Ian, I looked it up and now realize which one you're talking about. I was thinking of the previous version of the SE, and forgot about this new one. It looks pretty nice. Again, I wouldn't remove anything that's a heat sink, it's there for a reason, although those metal rings are probably unnecessary; I removed them from my Tube Box II as they only got in the way of frequent tube rolling.

Both the Tube Box II and my Current Wright 200C tube phono pre run pretty hot, but then again, the tubes are exposed so it's not a problem.

I'd really like to hear your impressions of the SE II because I don't know anyone else who has one.

[goraman]

I heard today that TAD uses the 9th generation Shung uang Chinee tube.
Word is it's cheap if not carrieing someones name like Tad or Groove tube but is very quiet,well ballanced and has a ton of gain. I wonder how much more gain than a Sovtek LPS? ANYONE?

[hammr7]

I heard today that TAD uses the 9th generation Shung uang Chinee tube.
Word is it's cheap if not carrieing someones name like Tad or Groove tube but is very quiet,well ballanced and has a ton of gain. I wonder how much more gain than a Sovtek LPS? ANYONE?

If it is a new tube, you have to realize that all of them are made in just two or three places at most, depending upon the tube. So there may be a Russian made version or two, and there might be a Chinese made version or two, or a single version from somewhere else in the world, but there aren't 5 or 10 different versions.

But when you go to buy new tubes, you might be confronted by a slew of brand names or no-names.

The only difference among the different private labels is the amount of quality control a company uses to weed out the klunkers. Some are willing to reject more than others. Some of the no-name tubes are those klunkers, just like in the 1950's when sub-par tubes were reprocessed and re-marketed. I promise you that very few tubes are trashed by the manufacturers. If one OEM customer won't take a tube, its cheaper for the manufacturer to dish it off to another customer unless it has completely failed.

But the best of any of the name brands will likely be close to the same, since they were made on the same line to pretty much the same specifications. And as far as I can tell, they are still working to get back to the excellence implicit in tubes from the 50's and 60's.

If it is a 12AX7 tube, shouldn't it have the gain that the 12AX7 specifications say it should?

[MIKEINEUGENE]

I have tried 4 different 12ax7 tubes in my Jolida JD102B and my favorite by far is the JJ ECC83S gold pin.I have also tried two different Groove Tubes(not sure of the exact#) and the JJ ECC83S.Differences are subtle to my ear but if i can actually hear better detail with a tube change like the JJECC83S Gold pin then i am all for it.I would suggest that you invest in a few different versions of the 12ax7 and listen for yourself.

[Mr. Lin]

And as far as I can tell, they are still working to get back to the excellence implicit in tubes from the 50's and 60's.


I believe this has come up here before, but I still don't understand why that's such a challenge.

[hammr7]

I believe this has come up here before, but I still don't understand why that's such a challenge.

It all has to do with technique. Tube production in the US and much of Europe had 30 to 40 years of experience by the time most of the great audio tubes were being produced. There was tremendous volume, tremendous competition, and as a result, tremendous innovation.

Only a part of this knowledge on tube manufacturing was formally transferred to the present. Today the specifications and basic design are known globally, but the various techniques used to implement tube construction are not. These ranged from proprietary materials to proprietary manufacturing methodologies. Much of that knowledge was lost in the 1980s as tube manufacturing wound down.

[Mr. Lin]

It all has to do with technique. Tube production in the US and much of Europe had 30 to 40 years of experience by the time most of the great audio tubes were being produced. There was tremendous volume, tremendous competition, and as a result, tremendous innovation.

Only a part of this knowledge on tube manufacturing was formally transferred to the present. Today the specifications and basic design are known globally, but the various techniques used to implement tube construction are not. These ranged from proprietary materials to proprietary manufacturing methodologies. Much of that knowledge was lost in the 1980s as tube manufacturing wound down.

Thanks for explaining that, it's really interesting, and it makes a lot of sense. I hope things will gradually improve as interest in tubes in the audio community seems to be growing, and NOS supplies will inevitably dry up.

[dividebytube]

concerning tube quality, make sure to check out the Mullard-Phillips video mentioned in a previous thread.
http://www.audiokarma.org/forums/showthread.php?t=162172

one of the biggest differences with modern vs. vintage tubes is the quality of the cathode chemistry, overall QC methods and of course the size of the marketplace. The majority of tubes made today are geared for the guitar market and cost is kept low as possible (but the quality high enough to reduce warranty issues). There are of course many caveats here - and plenty of examples of modern tubes that are just dandy.

[goraman]

I would like to make a strong statment,Some of the newer Chinnese tubes are very damed good and getting better all the time.I have been blown away by the TADEL84STR a 1950 RCA improved with larger cathrode,gold screen wire and thicker glass than the RCA before it.The sound is the best I have heard in an EL84 including Sylvanya and Phillips NOS.I can't spend 1,000 dollers on an octet of matched 1962 Telefunkens so there could be better but not in the $130.00 range and the new Mullard reissues are quiet but not real involving either.

[IanTY]

Pro-Ject Tube Box SE II. Now that I have had some time to familiarize myself with this unit, and it has had some time to settle down, I'd like to comment on it's acoustic character. Circa 50 hours. All auditions performed after one hour pre-heat.

The first thing to say about this phono stage is that it is fun. What changes to the sound path it does perform, are charming and fascinating. If you are replacing a transistor stage, for good or bad, you won't be able to stop listening to this Tube Box. It's magic maybe small, but it is very enticing. The build quality is very good, as too is the fit and in particular, the finish.

High frequency, very little change over the Rotel's transistors. This surprised me somewhat, as I know damn well this is making changes to the soundstage. Bass. Now this is a much larger and noticeable change. There's more, it's deeper, richer, is more realistic, simply put it is better. Vocals on the whole are a little more "in the room", smooth and pleasing, if a little laid back at times (almost a sense of HF roll-off). Overall, nothing mind-blowing in terms of dynamics or extensions in frequency response, but small, worthy improvements. If indeed this box is worth it's $600 price ticket, it is that with the appropriate recordings it absolutely does express itself in a liquid smooth way. Every now and again, it will render a studio acoustic or instrument perfectly - and you get that "real" sensation we crave with all systems. It's scary, but brings a smile to your face. The point being that with the Rotel, it never did that once. The Pro-Ject's ability to offer up enough resolution for high quality amplification of the DL-103 cart means that I can now experience a soundstage that is large, and a sense of instrument placement that blows the Rotel's tranny stage into the weeds. In this sense, it allows the DL-103 to shine. The pro-Ject gives the system a smooth, clean and spacious sound that is very comfortable on the ear, whilst having good dynamics and sufficient transient punch to make rock a pleasure at high volume levels. It is these attributes that make it acoustically desirable, addictive even . I consider it worthwhile because I am using it with a low-output moving coil cartridge.

It's benefits above the phono stage it replaces maybe less noticeable with a high-output moving magnet cartridge. I shall be keeping it, with my next guess being that I need a STASIS transistor main amp to complement the Tube Box (I'm on a budget, so a Nakamichi, not a Nelson Pass). The Tube Box SE II - Recommended, but with caution. - Ian.

Dunlop (Ariston) Systemdek IIX
Jelco tonearm
Denon DL-103 Cartridge
Pro-Ject Tube Box SE II (2x12AX7 Tung-Sol tubes)
Rotel RA-840B Integrated Amplifier (Solid State)
JBL Venue Series Stadium Speakers.
Sony OFC Interconnects
14-2 speaker cable.

If anyone wants more specifics, music auditioned etc. just ask. - Ian.

[mqracing]

... the specifications and basic design are known globally, but the various techniques used to implement tube construction are not. These ranged from proprietary materials to proprietary manufacturing methodologies.

I was talking to Paul Joppa (bottlehead) today and this very topic came up as we were discussing the EF86 tube.

I was telling Paul--- years ago (say early nineties iirc) I was talking to Charles Whitener (western electric) and he was telling me about some of the very specialized metallurgy that went into the WE 300B tube--- I remember him saying that the grid wire came from a custom melt done in 1964---

advantage that WE had was because they enjoyed the fruits of a monopoly---- when they wanted or needed something special--- it was available and they did not have the direct market pressure of competition in many areas.

This allowed them to spec in materials without much regard to cost and they also had a huge professional engineering staff to develop, test, and write specs for
materials and processes that would be moreso difficult for modern tube makers to bear the costs of.

MSL

[goraman]

I still think the best tube for little money is the Sovtek 12AX7LPS it is better suited to newer gear,the amrex bugal boy Telle's and mullards have little bass makeing this tube better balanced .It truly sounds awsome and has very high gain mids are very strong too.And on the bay can br found around $8.00 to $14.00 a real steal compaired to a true 1950's west german (Berlin) Telefunken at $160.00 each.

[IanTY]

"Recommended, but with caution" means if the cool sound of this amp is simply from having a pair of 12AX7's in the circuit, then you might want to save some money and try a Belllari VP129 ($250) or the Pro-Ject Tube Box II ($400). I am wondering if the extra expense is because the SE II has five or more load options (dip switched on the back, I run the 100 ohm setting for the DL-103).

Quick question. In terms of design, I presume the SE II is a single ended triode (Class A) design?

[IanTY]

I knocked up some photos of the factory supplied Tung-Sol 12AX7's in the Tube Box SE II, shown with the heat-sinks I mentioned earlier...

http://homepage.mac.com/iant1/TubeBoxSEII/

- Ian.

[Mr. Lin]

Thanks for the pictures Ian, I enjoyed getting a good look at the SE II. I imagine much of the extra cost has to do with the adjustable load impedance, which is probably a lot to do with how good it sounds with your LOMC cartridge. Now you should try some tube rolling!