They are interchangeable. The 6922 is the commercial-grade version, a step above the consumer-grade 6DJ8. In practice, it’s been a half-century since the phone company, avionics, or the military used these tubes, and they were replaced by FETs in TV’s by 1970. So they all go into non-critical consumer applications now.
They were never designed for audio use, so distortion and gain can be unpredictable. Testing is always a good idea to make sure they are suitable for audio use.
Quick definitions: consumer grade means it’s no big deal if it is out of spec or fails in use. It just annoys the consumer, nothing more. They go and buy another at the TV repair shop.
Commercial grade means telephone or broadcast use, where out of spec or failure in the field means loss of signal, and substantial financial loss. Think of "I Love Lucy" going off the air in Los Angeles. Like that.
MILSPEC means combat-ready, or aerospace use, where failure means loss of airframe, combat ineffectiveness, or loss of life. That is why MILSPEC costs at least 10x or 20x as much as consumer grade.
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I rolled these in a Steelhead and preferred the sound of old Telefunkens to the Siemens b/c they were more 3d though the Siemens were probably more linear. It may depend on the circuit and the overall voicing of the system. At the time I was buying them they weren't hard to find as true NOS. Today, have no idea.
I went through bags of 'em in my old ARC SP10mk ii mainly b/c the phono section was extremely microphonic. I could never get that preamp to play quietly although it was a jewel in their line at the time and went back and forth to ARC many times for factory mods.
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I like GE and Sylvania. All these tubes are interchangeable!
The 6DJ8 is a dual triode preamp tube. ECC88 is the European designation for this tube. 6922 and its European equivalent E88CC are premium versions of the 6DJ8. 7308 and E188CC and the CCa are super premium versions.
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Mazda 6922's are also really nice sounding tubes top to bottom. Use them in my Modwright Elysee DAC
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Great info, thanks one and all.
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My favorite is the Valvo CCa and second is Amperex PQ 6922 used in my Pathos Classic MKIII.
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I just switched a 2c51 tube in my MHDT DAC with a 6922 with adapter better bass and bigger soundstage
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Every piece of gear that I have owned that uses 6DJ8 tubes, I have had great success with 6922 & 7308 tubes. All are interchangeable.
In addition, my absolute favorite is the PCC88 (7DJ8). I have NEVER had a problem using these in ANY unit that uses the 6DJ8 family of tubes.
The National's are my favorite, (thanks Kevin!).
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are 6DJ8 and 6922 tubes inter-changeable
yes in all cases
the question of preferences is very long to answer, and highly dependent on what gear the tube(s) are being used in and what sonic profile is sought - different circuits and applications have very different sensitivities to the specific make/type of 6dj8 used
in general, excellent 6dj8 variants are old stock usa or european made ones from rca/amperex/philips/mullard, though very good quiet ones, especially matched sets, are getting expensive
more cost effective options are old stocks from japan and eastern europe (hungarian tungsrams , yugo made ei's, czech made teslas)
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6922 are a similar tube ,the 6922 are a bit more rugged the classic Amperex especially white label D getters are one ofthe best verywell balanced, Mullards are warmer older Blackburn type Also D getter , I am not positive on Siemens, , Telefunkin German made Mazda made-in France ,
6DJ8 can be used in many of these applications and are very good value
vintage tube services, or Brent Jesse Recording are pretty popular tubes are getting pricey, 20 years ago 5x+less pricey.
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Look for 7dj8's as well. Should be interchangable in almost all cases. Much cheaper and sound just as good. I ran 7dj8 Telefunkens in my preamps for years. Just wonderful.
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They are similar, but not the same.
Lot's of misinformation on the WWW about ECC88/E88CC/E188CC (including this thread).
DeKay
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Some of my favorite 6dj8 are the early 60s Mazda. I had a pair of these from Brent Jessee and they sounded incredible. Unfortunately they had kind of a short life in my CJ preamp. That thing was hard on tubes.
I replaced those with some mid 70s Reflektor 6922 . Another very good sounding tube and RUGGED. Those gave years of quiet operation whereas lesser modern tubes would sound good for a few months but get noisy. Like Audible Illusions the CJ preamps that used a 6922 ate tubes. The only modern 6922 tube that is consistently good in my experience is the Gold Lion 6922 gold pin , gold grid.
I like JJ tubes ,but their 6922 were hit or miss. When they were quiet they sounded great but in the CJ they weren't in there long before they were noisy
I use the JJ in my Quicksilver's driver tube and they are fine in that position
My Lab 12 DAC 1 Reference uses a pair of EH 6922 and after a year of use they still sound great . It sounds so good with the stock tubes I am actually afraid to make any changes. At some point I will replace them , most likely with Gold Lion .
The problem with 6dj8 and 6922 is that the NOS ones are scarce. I'm talking true NOS, not pulls that look and test new but genuine NOS
Once I bought a tube tester I quickly found out what tubes were good and what were junk. I discovered that most of the tubes I bought from trusted sources were as described. Strong emissions and balanced triode sections. Matched quads are matched, etc New production bought in a pinch from a music store were the worst. Readings were all over the map for 12ax7 and au7 type. They must get what everyone else passes on.
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BDP24,
The 6DJ8 tubes come in a large number of variants with different names for the US spec, Euro spec, and even Russian. These variants often come in 3 versions: a consumer (some can be really good), commercial (usually very good, but some can be AMAZING, and military spec (which can be better still. The commercial and Mil Spec tubes cost more, but you will get longer life out of them than the consumer grade; and they sound sublime.
I stay away from tubes made in Asian countries (too hit or miss), most tubes from the 1950s and 1960 are incredible, 1970s are really solid if not great, and some 1980s tubes can be really good.....but rule of thumb, older is better.
Some of my favorites are:
(1) Inexpensive - RCA "Clear top" 12AU7 - There are better tubes, but this is a steal at $20 a pop and easy to find in matched pairs, same with similar Russian tubes Voskhod 6n23p
(2) Next level - Better sound, higher costs. RCA "long black plates",1950s and 1960s, GE 5814 early 1960s, Amperex ECC88/6DJ8 Made in Holland", Philips 5963 (Mil Spec)
(3) "Damn these are good!) - Amperex 6922 "PQ" made in Holland, Amperex 7308 "PQ" made in Holland, Mullard 12AU7/ECC82, Mazda 12AU7 made in France, and Vokshod 6N23P "single wire) made in Russia
(4) Holy Grail and ungodly expensive - CCa made in Germany (mostly), 12AU7/6DJ8 "Pinch Waist" version, some people will even put the hard to find Vokshod 6N23P "Single Wire, Silver Shield" here as well
Advice: Read through the link I will post below, and use a reputable supplier that will know exactly what you are looking for. I have used Upscale Audio for rectifiers, but prefer Tube Depot over them. The best in my opinion is Brent Jessee out of Illinois......knows everything about tubes, carries a large selection.....even really rare tubes, and is a really honest guy.
http://www.audiotubes.com/6dj8.htm
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Thanks a lot everyone. Lots of great info, and links to sources of even more. I have a box full of the small signal tubes I bought back in the 90’s, gotta look through it again. I know I have some 7308’s (Gold Aero iirc), 6922 Amperex’s I believe, and definitely some RAM’s.
The Music Reference RM-5 Mk.IV I just received (according to the serial number one of the last twenty of the 1,000 RM-5’s Roger made. Bone stock, no mods) is fitted with a 6922 Mullard in socket V3 (line stage), a pair of Sovtek (isn’t that the 6922 ARC uses?) in the phono stage.
I have a bassist/guitarist pal who has some old Telefunken’s, but he’s not interested in selling any. Selfish sob!
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read this:
http://www.audiotubes.com/6dj8.htm
the first thing to read in learning about the 6DJ8 family is brent jessee's 6DJ8 page.
someone else posted it.
also, lots of people here are quick to offer misinformation. its often swift and immediate. its worse on facebook groups.
READ THIS:
http://www.audiotubes.com/6dj8.htm
learning the 6DJ8 family begins with familiarizing yourself with this information here. its not entirely correct, but its the best out there.
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I went to NOS Amperex 6922’s and they are wonderful. I tried several different ones and the Amperex were the best to my ears.
All the best.
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agree w @rodman99999
no misinformation posted here that i see on the op’s basic query
i have probably ~1000 pcs of 6dj8 variants i have collected over the years, from european cca’s, ecc288/188, 7dj8/pcc88, bugle boys, a-frames, tele’s, adzams, mazdas, cifte’s, russian rocket 6h23p’s and so on... reason being i have been a c-j preamp user since the 90’s, and for many years, my beloved premier 16ls2 used 6 at a time
folks who have answered here to the op like myself and rodman999 have a substantial experience base with this tube (and tubes in general)
that said, i don’t know why one commenter went on about 12au7 5814 etc etc... got nothing to do with a 6dj8 except the physical tube form
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Mid 70's Voskhod 6N23-P has been best to my ears.
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As I mentioned earlier some gear is hard on tubes so NOS 6dj8 probably aren’t a good choice. You want to use a 6922 , a ruggedized 6dj8
The Voskhod 6n23 tubes of the 70s are super rugged and last. Those are what I used in my CJ Classic 2se
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I have actually been trying to get away from this tube. As Lynn Olson mentioned earlier they were never made for audio use, and are very inconsistent
The good ones are $$$. A lot of “NOS” are pulls from test equipment and military surplus electronics.
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Wow.....ask, and ye shall receive. ;-) Thanks again, one and all.
@oddiofyl: Roger Modjeski talked about the virtues of the 6922/6DJ8 for audio use----specifically in regards to phono pickup applications, and it’s advantages over the 12AX7 (see the clio09 post above). And Tim de Paravicini, another "pretty fair" hi-fi designer (EAR-Yoshino, Luxman, Quad, Musical Fidelity) used the higher voltage 7DJ8 in his pre-amps (I own an EAR 868L).
The quietest phono/line pre-amp I’ve owned was a Dynaco PAS 2 as "modified" (redesigned, actually) by Frank Van Alstine, who used 5751’s in place of the stock 12AX7’s (cranked to full output there was only a hint of tube rush, no hum what-so-ever). So it will be interesting to see how the RM-5 compares in terms of noise. Low noise was a high priority for Modjeski. My pickups are very high output (5mV’s!), so don’t require much gain---another way to achieve low noise. The gain of the phono stage of the RM-5 is only 36dB, plenty for a 5mV signal.
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OFF TOPIC ALERT
bdp24, Did you see that Marty Stuart has a new album out today?
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@tomcy6: Yep, my copy is on its way, will be here next week!
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@oddiofyl e6922 isnt ruggediszed, but it is a better 6DJ8 several higher performance features including longer life. there are some in the 6DJ8 family that are either ruggedized or selected for ruggedness (tougher physical construction) like cv2492 (a version of the 6922 IIRC) )and, IIRC, a versoin of the soviet counterpart. 6n23p.
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Fantastic sources of information, thanks @jjss49 (and everyone else).
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They are interchangeable and they are not, all depends on the circuit.
Strangely enough many ECC88 sound better with more air and musicality compared to their bigger cousins like E88CC and E188CC. Unfortunately they do not last as long but still that depends on the circuit.
Throughout the years i have liked many tubes, all different, even the ones made with same tooling (Dutch, American, UK, French, Indian). French tubes for instance have the same nice mids of the Dutch tubes but with nore sparkle at the top end.
Always preferred the early Siemens to Teles and good value were the early Teslas and Tungsrams. Another excellent and underated tube is Raytheon 7308.
Anyway my top favourites are 6n23p Voskhods 74-79 period, followed by (not in particular order) early Cca’s, Amperex Bugle Boys ECC88 straight D- getter, Philips Miniwatt SQ early 60’s or E188CC PQ same period, Telefunken PCC88, Mullard E88CC-01 (CV2493), RT or Dario E188CC, Siemens E188CC A frames, Amperex ECC88 orange small o getter, Amperex USA PQ whites.
Great period for all western tubes (with exceptions) 1962-1965.
Most of them are good for phono stages and line stages but please remember that unless they are rugged like the russian tube all can become microphonic due to their construction. Line stages with high gain are not a very wise mating. A tube being noisy on a line stage can be quiet in a phono stage.
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No one has ever had a discussion this interesting a discussion about MOSFETS.
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Strangely enough many ECC88 sound better with more air and musicality compared to their bigger cousins like E88CC and E188CC.
i have found this to be true sometimes as well
experienced tube rollers understand that with small signal tubes, sometimes a small amount of sympathetic ringing/microphonics can add a positive character to the sound -- more air, more reverb, more depth to the soundstage - whereas a highly ruggedized military spec tube with dual or extra triple mica supports etc etc can sound ’dead’ in comparison
i have always liked the 60’s amperex bugle boys with ring getter (not a-frame) for that reason, in many cases they provide the ’goldilocks’ sound
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One great thing about tubes is you can use them to fine tune your system. If your phono cartridge is a tad bright, use softer sounding tubes. And visa versa. A tube pre-amp doesn’t have a fixed sound, it’s sound is changed by the tubes installed in it.
Speaking of phono tubes: has anyone tried 5751's in place of the 12AX7's in a Herron phono amp? I gotta give Keith a call, see what he thinks of the idea. The 5751 gives up gain to the 12AX7, but that works for me.
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Not in a Herron phono stage, but for what it may be worth, yes I have tried GE 5751 black plates in place of Telefunken, Siemens, Raytheon and other 12AX7’s in an EAR phono stage that I used to have. Good tube with a distinctively different character than the various 12AX7’s as a group. Needless to say each other 12AX7 had its own signature. The Tele’s being my favorites by far. The GE 5751 gave me a very tightly organized sound, somewhat “gray” tone with a little less sparkle up top. Reminded me of the way Shure phono cartridges sound to me.
This brings up something that I don’t think has been stressed enough in the otherwise great commentary above. It should not be assumed that a 6922 (or 7308, or…) will always be better than the “lowly” 6DJ8. Depends on the particular tube and the circuit that it will be used in. Based on my experience, I would take a good vintage Telefunken ECC88/6DJ8 over many other brand 6922’s and 7308’s that I have tried without hesitation.
Good luck.
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