Tubes Asylum: REVIEW: Tung-Sol 12AT7 Tubes by Luminator

Model:	12AT7
Category:	Tubes
Suggested Retail Price:	$25 and up
Description:	12-volt, medium gain, dual-triode vacuum tube
Manufacturer URL:	Not Available
Manufacturer URL:	Not Available

Review by Luminator on July 26, 2002 at 12:38:32
IP Address: 66.47.253.226

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for the 12AT7

The 1993 Stereophile show was the first time I saw tube equipment in abundance. Prior to that, I had only seen a handful of pieces here and there. At the time, a large percentage of the showgoers believed the myth that tubes and solid state had identifiable house sounds. I was one of them. But when we went from room to room, we discovered that it did not matter whether a demonstration had tubes, solid state, or both. The sound was as variable as the weather.
To this day, people still ignorantly cling to outdated myths. They still tune out, and insist that tubes must sound this way, solid state must sound that way, CDs have to sound like this, LPs have to sound like that, and on and on.
The Tung-Sol 12AT7 is a tube that can shatter one's preconceived notions. I shall get to that shortly, but first, a little background.
The Tung-Sol 12AT7s that I have come across were made in the 50s to early 60s. I have no idea where or for how long Tung-Sol produced these tubes. The getter hoops come in different shapes and sizes. A few have round "O-shaped" rings, others have a big "U," and some have a two-piece hoop, formed with a "U" and a straight "I," thus making a big "D." I have seen both gray and black plate Tung-Sols.
I do not know anyone who has a tubed tuner, so I have no idea if or how the Tung-Sol 12AT7 works in such devices.
A large percentage of the Tung-Sol 12AT7s which my acquaintances and I have tried became noisy. Yet, those that were not noisy stayed that way for years. One "D-shaped" getter tube hummed in the Earmax, yet, it worked okay in an AudioPrism Debut II. Go figure.
A few months after that 1993 Stereophile show, I was hanging out at a local hi-fi store, when I met a guy who was shopping for a preamp. He liked the transparency of the Audible Illusions M3A (I think that was the iteration at the time), but he did not like the high gain and the rate at which the unit destroyed precious and expensive 6922s. So he ended up getting a Sonic Frontiers SFL-1, which uses just one 12AT7. Throughout the years, this guy's SFL-1 has been a useful tool in evaluating 12AT7s.
Some time in late 1994 or early 1995, I asked the guy about his SFL-1. He said he had done some tube rolling, but could never get rid of some hiss. He mentioned that he liked the "brash" sound of the Tung-Sol 12AT7, but that two of them went noisy on him within days or weeks. One fine spring day, I went over to his house, and heard his system, which, if I remember correctly, had the CAL Icon II with HDCD, a Counterpoint solid state amp, AudioQuest cabling, and Vandersteen 2C (I don't know which version) loudspeakers.
When we put on the Cranberries' "Everybody Else Is Doing It, So Why Can't We," it was slow, dull, warm, opaque, and uninvolving. So the guy shut everything down, took out the Tung-Sol 12AT7, and subbed a Mullard Gold Pin 6201. The sound got even more boring! Yikes, it was one of the worst sounds we ever heard. But that experience taught us that the Tung-Sol 12AT7 is a much clearer, faster, livelier tube than the life-sucking Mullard GP 6201.
This guy replaced his AudioQuest Lapis, Quartz, and Clear with Kimber KCAG and 4TC. Wow! His system now sounded more detailed, open, and alive. He then got replaced the API Power Wedge 1 with a Vansevers PLC, and the soundstage finally blossomed. Now, we were finally able to hear the true sonic superiority of the Tung-Sol 12AT7 over the Mullard GP 6201.
Over the years, this guy has upgraded his system. But he still keeps his SFL-1 in the closet, and pulls it out every now and then. A few weeks ago, while evaluating the Telefunken ECC81, we resurrected the SFL-1. While listening to the remastered versions of Peter Gabriel's "So" and Madonna's "Like A Virgin," we frowned, and looked at each other. "Where have we heard this type of sound before?"
There was a slight lack of soundstage depth, as if the rows of music had been placed closer together, front to back. It was odd. The drums on "Sledgehammer" had the reverb and ambiance of being back at the rack, but it was physically placed between the two loudspeakers. And then it dawned on me: this is how the Krell KRC-HR does soundstaging. Uh oh, I can hear the tube lovers start to squirm.
I know another audiophile who swears by his VTL ST-85 and Tiny Triode TT-25s. He has a home theater setup with these amps and a Classe' SSP-25. Like me, he has taken heat for using solid state preamplification and vacuum tube power amps. But those who have actually taken the time to hear his system know that it sounds accurate, clean, and well-balanced. The VTL amps have a reputation for eating tubes, and this guy did say that if a tube does get noisy, it usually does so within a few days. He reports that he lost three Tung-Sol 12AT7s like this.
At any rate, the Tung-Sol 12AT7 is one of the few 12AT7s that do not sound rolled-off, sandpapery, or blubbery. There is a bit of an edge that makes some movies hard on the ears, but that is more of the movies' fault. When we watched "Bring It On," the sound was fast enough to keep up with the cheerleading routines. Contrast that with the sloppy handing of the Mullard GP 6201 or the slightly squid-like feel of the Telefunken ECC81 and RCA black plate 12AT7.
On the other hand, one of this guy's audio buddies hates the Classe'/VTL system. I heard him exclaim, "Ugh, what tubes? I don't hear no tubes. This s*&# sounds like solid state!"
Another guy I know has had the Conrad Johnson PV-10A for many years. He says that he has had to replace the 12AU7s in the linestage several times, but he has never had trouble with the phonostage tubes, which include a 12AT7. In this position, lack of noise is critical. Even with Upscale Audio's quietest 12AX7s and 12AT7s, the PV-10A's phonostage is hissy.
He has had the SOTA Comet and Sumiko Blue Point Special for about as long as he has owned the PV-10A. In 1997, I lent him a Tung-Sol 12AT7, and, five years later, he's still not giving it back. He claims that this is THE 12AT7 for the PV-10A. I can see why. With the Tung-Sol 12AT7 in his preamp, his Comet sounds upbeat, enthusiastic, snappy, engaging, and fairly open. You will not be able to resist crooning to ABC's "Look Of Love." Your shoulders and hips will jut and strut sassily, as you follow Bananarama's version of "Venus." You'll don black eyeliner, as you sing along to Human League's "Don't You Want Me." You'll bathe in Sheena Easton's "For Your Eyes Only." You'll be rapping like a stuttering idiot when you play Falco's "Rock Me Amadeus." Who said that tubes are warm, fuzzy, slow, and rolled off?
This guy has used the Tung-Sol 12AT7 for almost five years (it was NOS when I lent it to him). This particular tube has been trouble-free, and shows no signs that it is about to give out. Who said that tubes can't be as reliable as transistors?
The Earmax uses two 6GM8s, and one 12AT7. There is not much variety in 6GM8s. I strongly recommend that you purchase tested and matched 1960s made-in-Holland Valvo 6GM8s from Upscale Audio [I have no affiliation with Upscale Audio]. But if you have an Earmax, you can experiment at length with 12AT7s. So far, I have found only three 12AT7s which are sonically acceptable in the Earmax. One is the $135 Telefunken ECC801S, probably the most neutral 12AT7 ever made. Two is the CBS 7728, which is even rarer than a colorless, flawless, round cut, one-carat diamond. The third? Why, none other than the Tung-Sol 12AT7!
In the Earmax, the RCA 12AT7 (black or gray plates) squashes the treble. It's as if it needs Dolby HX Pro. The G.E. 5-Star 6201 bloats the images, so the overall sound is too thick, and you cannot "see" between the images. The Sylvania Gold Brand 6201 collapses the soundstage, so that the images exist in a tiny spot within your head. Furthermore, it adds a sandpapery grain to instrumental textures. The Mullard GP 6201 is so bad, it's like sticking warm water into your ears. The Sylvania black plate 12AT7 is the opposite of the Mullard; it is like a praying mantis clawing away at your ears. Though its tonal balance is okay, the JAN Philips 12AT7 doesn't have enough resolution, so the music sounds bleached out. The regular Telefunken ECC81 is okay if your system leans to the sharp side. But in neutral systems, it a touch lazy, as if a baserunner is not busting his tail down to first base.
The Tung-Sol 12AT7 has lots of air, and does not rob the treble of body, shine, and sparkle. Check out the keyboards on Starship's "No Way Out." Even though you are listening through headphones, the Tung-Sol does nothing to diminish the height of the ambiance cues surrounding the keyboards. On Petula Clark's "Downtown," the gobs of reverb on her voice makes her sound like she is singing in a big hall, not a small studio. The Tung-Sol 12AT7 keeps the recording intact, just as it is.
People who do not like the vivid nature of pop music recordings may not like the Tung-Sol 12AT7 swashbuckling its way in the Earmax. But that is how pop music is. To make it sound otherwise would be wrong. Still, some listeners prefer to tone down up-front recordings, and these people will not like the Tung-Sol 12AT7. In fact, one co-worker who came over to my house said, "Ouch! Your Earmax is more solid state than my Audio Alchemy."
So how does the Tung-Sol 12AT7 sound in my main system? As many Inmates know, I have the AudioPrism Debut II, which uses four 12AT7s. Thus, it is a good tool for checking out 12AT7s. The problem is, with some brands, it is hard to find two matched pairs of 12AT7s. While my audio acquaintances and I have had small handfuls of Tung-Sols, it wasn't until recently, when I was able to put together enough matched pairs for use in the Debut II.
First up is Bruce Springsteen's "Born In The USA." Because the Tung-Sol does not round things off, you do not need to look at the video, to see the strain on Springsteen's neck. Max Weinberg's drums are punchy and powerful, and his cymbals are appropriately brash.
The Pet Shop Boys' "I Wouldn't Normally Do This Kind Of Thing" jumps to life, maybe a little too much. Here, you can tell that there should be more space, front-to-back, between the layers.
The Motels' "Only The Lonely" and "Suddenly Last Summer" sound completely different. The former sounds just right. The latter sounds shut down, hemmed in, wobbly, and lacking in treble extension and air. The Tung-Sol 12AT7 has enough resolution and neutrality to highlight the differences in sound quality between these two songs.
On Men At Work's "Who Can It Be Now," the instruments are placed too far forward, and here is where the slight restriction of soundstage depth becomes a liability. Ditto for Glenn Frey's "The Heat Is On," Motley Crue's version of "Smokin' In The Boys' Room," and Wham!'s "Wake Me Up Before You Go Go." This foreshortening of depth does not allow Haddaway's "What Is Love," and Slayer's "Mandatory Suicide" enough room to breathe. Thus, the rhythmic integrity is compromised. Metallica's "Wherever I May Roam" glistens beautifully, but the flow, movement, and timing are too stair-step in approach.
I like the Tung-Sol 12AT7 in the Earmax, where the slight lack of depth is not a factor or concern. But in the main system, visitors stare at the Debut II, take a listen, and then frown. Here's how one guy put it: "I don't like the Tung-Sols. What's the f&%$#@! point? They make your tube amp sound like any ol' solid state boat anchor." So, back in went the Telefunken ECC801Ses. But I'll save that story for another day.
-Lummy The Seahorse

Product Weakness: not as common and widely available as other 12AT7s; too many become noisy; some people call this a transistor-in-tube's-clothing
Product Strengths: those that are quiet stay that way for a long time; good sound at a relatively affordable price

Associated Equipment for this Review:
Amplifier:	AudioPrism Debut II
Preamplifier (or None if Integrated):	Mark Levinson No. 380 and Krell KPS Standard
Sources (CDP/Turntable):	Theta Jade and Mark Levinson No. 360; Fanfare FM FT-1; Rega Planar 3/RB-300/Grado Platinum
Speakers:	ProAc Response One SC
Cables/Interconnects:	Tara Labs The One and The 2; RSC Reference Bi-Wire; Air AC and The One AC
Music Used (Genre/Selections):	Pop, rock, metal, oldies, dance, Hawaiian, plus some classical and jazz
Room Size (LxWxH):	16 x 15 x 8
Room Comments/Treatments:	ASC Tube Traps
Time Period/Length of Audition:	off and on for eight years
Other (Power Conditioner etc.):	Tara Labs AD/10B and AD/6C
Type of Audition/Review:	Product Owner

Product Weakness:	not as common and widely available as other 12AT7s; too many become noisy; some people call this a transistor-in-tube's-clothing
Product Strengths:	those that are quiet stay that way for a long time; good sound at a relatively affordable price