Best 6922 tubes for DAC


I am thinking about replacing the stock Sovtek 6922 in my Audio Logic 24 MXL dac. Can anyone recommend NOS that would work well in this dac? Please try to describe sonic characteristic of the tubes you are recommending.

Rest of the system:

Joule Electra LA 100 preamp and Stargate amps, Merlin VSM speakers, Sony X707ES modified transport, Cardas and Stealth cables.

Many thanks!!
drv
What kind of sound do you prefer in your system: accurate from top to bottom, warm and bloomy midrange? Your sonic preferences will narrow the recommendations.
I have tried several in my MXL. The ones that are most pleasing to me are Siemens CCa.
If you do a search in the forums for "Audio Logic", there are a few threads about this topic. If I remember correctly, several people preferred Mullard and Tungsram.
Anything by Phillips (e.g. Amperex, Mulllard) will be a huge improvement over Sovtek. I'd recommend Amperex Bugle Boys or maybe 7308s for the ultimate upgrade.

-Ed
This has been an invaluable source in my quest for 6922/7308 tubes. It's called Joe's Tube Lore, and it's quite thorough. Although just one man's opinion, I've found the comments to be spot on when I've tried different 6922 and 7308 tubes.
I am using Philips Miniwatt 'SQ' in my 24MXL- very full-bodied across the spectrum, perhaps ever so slightly less detailed than the Siemens, but more full-bodied bass IMO, and a wonderful midrange...
I agree with Sutts about the Philips "SQ". The Amperex 6922 & 7308 fall between the Siemens 7308 and Philips SQ on the detail spectrum...the Siemens being the most detailed of the bunch, IMO.
I recently upgraded my amplifier's input tubes from Sovtek 6922's to EH 6922's. They are very similar, with better bass response coming from the EH tubes. You might give these some consideration, at $20 each new with gold pins. Don't go down the NOS road unless you've got so much money that you've forgotten what One's and Five's look like, and you'd better have reliable sources, because (IMHO) many of the NOS tubes circulating through cyberspace right now are actually OOS tubes (Old Old Stock) or just plain OJ (Old Junk).

Cheers and Good Luck
My biases
Take my comments within the context of my system which, although CD based, is neither grainy nor euphonically rolled off on top. As a result I value good high frequency extension as it comes through in a clean, grainless and non fatiguing manner. I also like a dynamic, transparent and lucid sound with dimensional images within the soundstage. I also like to have the performers in the room with me so I like a slightly forward, but still non fatiguing balance. If your rig is bright and forward you might want to skew towards the tubes which are softer on top & a little more laid back than my favorites. But frankly, if you are using Sovteks now, this shouldn’t really be a big problem.

Sovtek 6922 (polished steel pins) A bit sterile and lifeless, lacks a bit in dynamics, rolls the deep bass just a trifle and can occasionally sound a bit hollow in the mids. In short Yawn...

Russian 6H23N (steel pins) A Russian tube imported by the good folks at Lamm Audio. It came stock in my amps & is a slight improvement on the Sovtek. While basically similar to that tube, it has a bit more jump, slightly improved deep bass and slightly more palpable mids. The differences are not huge however, so whether or not its worth it to you is an individual decision....

Edicron 7DJ8 (with shield, steel pins) A bit livelier NOS kind of sound than either of the above tubes. A little thin though compared to my favorite Amperexes & Siemens. While this tube represents an improvement over current production tubes I couldn’t live with it (but then I don’t use and AI preamp, so I can run any 6DJ8 I want without worrying about tube life sorry guys!) Ultimately, if I were limited to the first three tubes, this would be my choice.... Also, the source of this tube is a bit questionable. See the Valvo 6DJ8 below for more comments.

Siemens E288CC (with shield, gold pins) More transparent & dimensional with better bass than the Edicron. Also has more palpable vocals and a more lively, real sounding presentation than any of the above. But it’s not even close to Siemens best in this family. Expensive and hard to find too. But the best so far....

Siemens 6922 / E88CC (with shield, gold pins) Now things are getting more interesting. It’s lively, has a palpable & real quality to individual performers with greater dimensionality than any of the above tubes. Warm, lively & transparent with an extended high end. This is a classic tube and an excellent choice in this family if your system is not already over the top in the high frequencies. Often found labeled as a made in West Germany RCA for as little as $20 a pop. An absolute bargain....

Siemens 6922 / E88CC, RCA label (A frame, gold pins) This tube is similar to the earlier 6922 above. Vocals are slightly bigger and slightly more forward, the highs are a bit softer and the overall sound of the tube is a bit warmer. Music is presented with a warm, vibrant acoustic. Very nice & musical, though it might be a bit dull in a system that’s already dark in balance. Another excellent tube...

Siemens 6DJ8 / ECC88, RCA label (with shield, steel pins) Kind of lives in between the two 6922s above. Warm & vibrant, with a slightly forward balance similar to the A frame. Slightly more extended highs than that tube, however. Another very nice tube, frequently found labeled as a made in West Germany RCA....

Siemens CCa (with shield, gold pins) This tube is a premium version of the 6922. It is also one of rarest & most sought after tubes in this family and is priced accordingly when you can find it (not often). Slightly more dimensional, transparent & focused sounding that the

Siemens 6DJ8 and 6922s above. It lacks a bit in bass punch
compared to those tubes however and is slightly dry sounding in comparison. In short maybe better in some ways, but not a reason for living. In other words, if you are stuck with living with the lesser Siemens tubes don’t worry about what you are missing....

Siemens 7308 / E188CC, RCA label (with shield, gold pins) - Sacrilegious comment time. I prefer the slightly warmer, more vibrant and wetter sound of this tube to the sound of the CCa. Closest sound among the Siemens line to the sound of my favorite Amperexes (coming up soon!)

Siemens 7308 / E188CC, Phillips SQ label (no shield, with getter halo) Warm & transparent. Very close to the shield version above in overall sound quality. Another excellent tube...

Telefunken 6922 / E88CC (with shield, diamond bottom, gold pins) Slightly hollow mids, not as rich as the best Siemens and Amperex. A bit like the Siemens E288CC, though a bit better than that tube. A good tube, but the more common & cheaper Siemens 6922s are much better choices IMO. (Absolutely pounds the Russian tubes, though!)

Sylvania 7308, RCA label (with shield, steel pins) Vocals are sharper & less refined than Siemens, Amperex and the Teles. Not at all a bad tube & better than the Russians in some ways. Lively, vibrant, forward & good bass if a bit of an edge and a little brash. Not a great tube, but a good tube for the price. If your system needs some energy and high frequency oomph and you don’t have much cash this tube is a best buy....

Sylvania 7308, Siemens counterfeit (with shield, gold pins) The morons who did this relabeled counterfeit of a Siemens didn’t even bother to rub off the original made in USA label. An object lesson for care in chasing desirable tubes, there are a lot of fakes and relabels of tubes like the Siemens 7308 and CCa based on the Sylvania & even the Tungsram. I’ll give some hints on how to avoid getting ripped off later in part 2 of this review. This tube is not quite as sharp as the above steel pinned version, but it is still a bit forward. Frankly I prefer the steel pin - this one is missing just a touch of that ones life...

Valvo 6DJ8 / ECC88 (with shield, steel pins) Slightly thin sounding vocals with more air than body. Soft bass, sounds a bit like the Edicron 7DJ8 and that shouldn’t be a surprise this tubes internal construction is identical to that tube (at least on my pair, anyway). These tubes were obviously made at the same plant. In fact, close inspection reveals that every aspect of this tubes physical construction is absolutely identical to the Edicron down to the fat, round top, Russian style bottle and the bright red color on the pins where they pass through the glass. In fact the bottles on both tubes are identical to the Sovtek 6922 so these tubes were either made in Russia or they were made in an Eastern Block country equipped with Russian tooling. Edicron labels their boxes London but that ain’t where either of these came from....

Raytheon 7308 (with shield, steel pins) OK mids, soft on top, good bass. Better than the Russians, but not by tons. As good as the Sylvania 7308 steel pins, but in a different sort of way. Not a great tube, but a good one...

Ediswan CV 5358 (splatter shield, steel pins) Good, palpable vocals, nice upper & mid bass with a nice sense of impact in that region. Good if slightly soft highs. This tube is almost in the same class with the Siemens gold pins if just a bit softer in balance on top...

Mullard 6922 EE88CC, Great Britain (shield, gold pins) This is a Great Britain manufactured tube, not all of Mullards are in this family with a lot of these tubes being sourced form Amperex in Holland. As I understand it,

Mullard’s 6DJ8 tube tooling came from Amperex and it looks like it every Mullard in this family I’ve ever seen looks like an Amperex inside down to the smooth edge, slightly square shaped mica spacers. Perhaps as a result this tube owes a lot to the Amperex 6922 family when it comes to sound quality. This guy’s got good bass, nice mids and a wet, ambient soundstage occupied by slightly smaller and images than the Siemens and Ediswans. A nice tube overall though not quite up to the level of the best Amperexes.

Mullard CV 2493, Great Britain (no shield, getter disc, gold pins) This tube lacks a splatter shield with just a small metal wire holding a solid metal disc with dimples around its perimeter above the upper mica spacer. The sound of this tube is very different from the 6922 above, with a less pronounced bass and less vivid highs. It does have a very nice midband, however, combined with a deep & dimensional soundstage. If you find the 6922 Mullards (and
Amperex 6922s to follow) too pronounced at the frequency extremes this tube could be a valid choice representing a viable tuning alternative...

Mullard 6DJ8, Great Britain (shield, steel pins) One of my pair of these died a year ago (moment of reverent silence please....) so I couldn’t compare it directly to the others in this shoot-out. Given the vagaries of long distance auditory memory I will not comment on specifics other than to say I remember it as quite good and worth checking out if you get the chance.

Amperex 6922, JAN Orange label, US (shield, gold pins) A little sharp in the upper mids / lower treble. Good upper bass and highs. Vocals lack balance & body A bit disappointing. This tube sorta sucks...

Amperex 6DJ8, Orange globe logo, Holland (shield, steel pins,) Much better than the above tube No comparison in fact. Warm, vibrant, lively, grainless, transparent Amperex sound. Killer tube. Almost as good as my reference

Amperex 6922s (coming up soon). I slightly prefer this tube to the best of the Siemens 6DJ8s, 6922s & 7308s.

Amperex 6DJ8, Bugle Boy logo, Holland (shield, steel pins,) Similar to the above tube with a slightly larger soundstage & more ambience, trading off a bit of impact and bass extension. I prefer the globe logo above to this tube by a small margin in spite of this tubes vaunted reputation. But still a good tube...

Amperex 6DJ8, RCA, Holland (A frame, steel pins) - More forward vocals than the Bugle Boy. Sweeter highs too, with bigger, slightly less focused images. A little closer to the Globe logo 6DJ8 overall in character than it is to the BB....

Amperex 7308, Orange globe logo, US (shield, gold pins) More focused and palpable than the Bugle Boy & A frame 6DJ8s. A bit like the Globe Logo Holland 6DJ8 overall. I still prefer that tube to this one but this is still a pretty good tube...

Amperex 7308, JAN, green label, US (shield, gold pins) Very similar to the globe logo 7308 above. Both could use a little more bass kick & body to vocals in my rig, but could represent a useful tuning option in a system where my favorites come across a little too lively and forceful. While this tube is highly recommended by some dealers I think a few of the other Amperexes here slightly best it...

Amperex 6922, PQ, white label, US (shield, gold pins) Another very good Amperex tube. Warm yet lively, focused, grainless and transparent. A winner one of the best. Dynamic with punchy bass to boot....

Amperex 6922, PQ, white label, Holland (shield, gold pins) Slightly more forward midrange than the US version, above, pushing vocals a bit more forward in the mix. Otherwise, very similar. Another winner...

Amperex 6922, PQ, white label, Holland, D getter (shield, gold pins) Another winner. Slightly less midrange emphasis than the round getter halo Holland above, with a bit more life. Good treble extension. An excellent tube...

Amperex 7308 white label, US (shield, gold pins) My favorite 7308 by a small margin. Bass is a bit better than the Holland 6922s. Vocals lack just a touch of body compared to the best Amperex 6DJ8s & 6922s. Still a very good tube overall...

Amperex 6922, USN, white label, US (shield, gold pins) Sounds very much like the US white label PQ. Another excellent tube though it may lack just a bit of that tubes warmth & body, but I’m quibbling here....

Amperex 6922, Mullard, Holland (shield, gold pins) Sounds a lot like a Holland PQ white label. In other words a very nice tube with slightly forward vocals and a lively transparent sound...

Amperex 6922, PQ, white label, US, pinched waist (shield, gold pins) Yeow! My reference tube. An absolutely gorgeous sounding tube with an unusual physical characteristic. The glass of the tube is actually slightly pinched at the about the point of the upper mica spacer. This reduces the tube’s diameter at that point resulting in a subtle hourglass shape. The reason for this was for the bottle to actually clamp the upper mica space at its rounded corners resulting in a more rigid, less microphonic, structure. The result? A tube that defines the Amperex house sound: Lively, transparent & detailed with extended highs, yet absolutely no grain, with a punchy, dynamic bass. Mids? Lucid and palpable, thank you. The best tube in the 6DJ8 family IMO. The only downside? These guys make the rare Siemens CCas look absolutely common in comparison. Cost? If you have to ask.. If I were hunting for a tube almost as good and much more accessible? I’d hunt down some US white label PQs and live contentedly until the gods smiled on me and I lucked into some of these...

Posted by Joe S on March 30, 1999
In my Audio LOgic DAC I use Tele 6922's purchased from Tube World.com They are the Pearl cryovac version. At $450.00 a pair they are stupidly expensive but easily the best I've heard. I've had a gagggle of NOS Amperex, RCA, Sylvania and Mullard 6922, 6DJ8, and 7308 in the DAC but the Tele's were the most effortlessly musical period! FWIW-plugging the AL DAC into a Audio Magic Mini Matrix was the best peformance upgrade I've tried And I've messed with Jerry's DAC alot over the last 10 years
"Stupidly expensive" and Tube World go hand in hand in my experience.