Preamp 6922 tube help

I suggest you call Andy at Vintage Tube Services. He will give good advice and sells great tubes.

I agree that Andy is great to deal with. You have to call him since he doesn't check his email.
If your Amperex sounded rolled-off, then they were dying or defective. Amperex, especially Bugle Boys have deep bass extension, liquid smooth mids, a 3D soundstage. They do have extended highs, however.
I would recommend RCA based on your needs.

Upscale Audio...
https://www.upscaleaudio.com/collections/preamp-tubes/6922-6dj8-7308-pcc88?page=1

Andy at Vintage Tube...
616-454-3467

I've had several amps that used  6922's and found Amperex to be best all around . BUT there are many fake Amperex being sold, often by people 
who don't even know they are . Won't happen with Andy so worth what he charges .
As lowrider57 said , also hard to go wrong with RCA as well .
There were some nice sounding ones labeled audio research company
W. Germany but not seen them on here .

GE 6DJ8 from 1960's is a real nice tube!

These might surprise the hell out you.  They did me.  I've owned and heard so many different 6dj8/6922/7308 variants that I can't remember them all.  These are really spectacular and don't cost all that  much.

https://www.upscaleaudio.com/collections/preamp-tubes/products/matsushita-national-pcc88-7dj8?varian...

Keep the CCa. Maybe try changing another component in your rig... interconnect, sit CD player on layer of cork tile...etc.

I was thinking about changing the capacitor on the speakers, so far other things to make the system warmer, I didn't like. 

I was thinking of Jupiter Vintage Tone, I am running Jenzen Superior 10uf right now, and they are pretty flat sounding capacitors, which the tube tilts to bright. 

I removed the preamp from the linear power supply to make it sound warmer, I didn't like the sound of that. I might take the preamp off the isolation blocks. 

I like the 6h23neb tube the best as it has a nice all around sound.  I believe I bought them from The Tube Store.  Uncle Kevvy at Upscale may have them as well

Called Andy he recommended two tubes to try 

Amperex Mids 60s A Frame 

and 

Telefunken West Germany. 

What does he mean when he says a tube is dry sounding? 

I have liked the Amperex tubes, and would trust Upscale Audio for these.
 Another option that was recently recommended by my preamp’s designer are these https://www.musicdirect.com/tubes/ifi-nos-5670-6922-vacuum-tubes-pr

Early to middle 1960s Amperex 6922 PQ white label USA made. Also the 7308 PQ white label USA made from the same years.

Joe’s Tube Lore
https://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8

Brent Jessee
http://www.audiotubes.com/audtube.htm

.

Another great sounding Siemens tube is the early/mid 1960s 7308/E188CC all grey plate tube. Some were sold here in the states under the RCA label 7308/E188CC.

Not this tube though.
http://www.thetubestore.com/Tubes/6000-to-9999-Types/SIEMENS-E188CC-7308
Note the wire support for halo getter. This is a later year version. It is also not an all gray plate like the early 1960s 7308/E188CC tube. It also doesn't sound anything like the earlier version tube.

Here is an example of the early 1960s Siemens CCa all gray plate tube. Notice the halo getter support.
http://www.ebay.com/itm/2-Siemens-CCa-6922-6DJ8-Vacuum-Tubes-NOS-NIB-Amplitrex-Tested-Matched-Gold-P...

What does he mean when he says a tube is dry sounding?

This applies to a tube that is completely neutral and flat across most of the frequency spectrum. It does not sound full-bodied or warm or "tubey." In the case of Telefunken, it may sound analytical, not what you are looking for.
Amperex has different variants that have lot of soul and a "you are there" feeling.

Good links provided by jea48 to learn about the different sonic signature of tubes. A must for tube rollers.

Totally avoid Russian variants they are all dry and cold! Go NOS!

Sample and judge for yourself.

Upscale is a good source. The owner is sometimes prickly to deal with IMO.

Another good source is tubeworld.com - Talk to the owner - he has common sense, is honest, and gives great advice. lots of hard to find NOS tubes. good, easy to use website

I've tried a lot as well, and the based on my personal taste (detailed, yet fuller midrange with great extension and clarity) were the early 1960s USA white label Amperex 7308s.  I've got an extra pair if you're interested and can provide the specs.  The Holland Amperex 6922/7308 is extremely warm and rich, and the extremely rolled off.  Best of luck.  Though some say the orange and green label is the same as the white label Amperex, they do sound different to me and feel the white label is the best, especially early 60s medical/military grade. 

jea48, i think you made a mistake on those grey plate Siemens CCas.  If you take a closer look, those are the silver plates or shields.  You can see on the nearer tube where the shield is pinched (below the final s in Siemens) that it is clearly a shiny metal.  That is what you don't want.  Another indicator is the aluminum tag with the tube codes stamped on it above the silver shield.  These are later vintage tubes and are supposedly (I've never compared them) brighter and poorer sounding in general than the grey shields.   The grey shields have the codes etched into the glass like other Phillips tubes.

That may be the OP's problem.  If he got a pair of these instead of grey shields  he would probably be disappointed.

I am really looking for a tube that has a high sense of realism in the presentation. The CCa did it for me if it wasn’t for the listening fatigue, you heard every pluck of the strong, the bass was nice and tight, voices was clean and clear. In my experince tubes that have a high sense of realism were also very accurate in recreating tones. 

If anyone wants to study up on Phillips tube codes here's a link to the manual:
https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf

I will just add that you will probably only find tubes with the  'NEW' CODE format as seen on page 3, and probably only the top illustration with the codes etched into the glass on the side of the tube.

tomcy6,

Thank you.
You are correct. I guess I just didn’t check out the pictures close enough. Taking another look sure enough I clearly can see the shiny metal plate and the aluminum tag with the stamped date codes. In my rush I guess I was trying to point out the differences in the two halo getter supports. The eBay seller says grey plate in his ad. Though he doesn’t say all gray plate. I knew better, I should have taken a better closer look at the pictures.

How about the boxes shown in the ad? I though the blue / yellow boxes were for the older all gray plate Siemens tubes. Later dates were the orange / blue boxes weren’t they?

http://www.ebay.com/itm/2-Siemens-CCa-6922-6DJ8-Vacuum-Tubes-NOS-NIB-Amplitrex-Tested-Matched-Gold-P...

For what it’s worth my first purchase of a pair of Siemens CCa tubes I bought here on Agon around 2004-2005. I was green and did not know what to look for. I thought I was buying the real deal but instead bought a pair with the rod halo getter support. And of course they had the same things you pointed out in your post.

Thanks again,
Jim

thewatcher,  I think you're going to have to talk about your system and the sound you want with the various tube sellers recommended and buy from the one who convinces you he's got what you need.  Tubes will sound different in different gear and I don't think we can accurately predict what will work for you.

Not sure which Amperex you tried, but I found the early 60's 6922/7308 to be the best in my system.  Far superior to the later ones.

Jim, You're right about the boxes.   I think the seller is trying to fool somebody with the boxes and the way he took the picture. You can see they’re shiny shields but only if you look at them closely. For the price he’s asking, those should definitely be NOS grey shields. He should point out that they are not. But he’s got 100% positive feedback. You gotta watch out on ebay!

I tried quite a few 6922 variants. By FAR the best was early '60's Telefunken  specially selected for Hewlett Packard  for use in their aerospace test equipment.

The boxes bear the HP logo on their seals.

I think that these were the last tubes that HP trusted anyone to supply with factor seals. After this, they hired summer students to test cartons of tubes, and kept only 2 or 3 out of 100. The rest went in the dumpster. New Amperex 6922's. In the dumpster. So went the stories in the engineering schools in LA at the time. Which would explain why HP branded tubes cost the EARTH.

Good luck finding any. The last NOS sleeve I saw for sale was nearly 20 years ago, and I bought it too dearly.

I am not an expert, but I don't think the Amperex A frames are nearly as good as the earlier halos.  I have had particular good luck with 1962 and 1963  Amperex USA with Navy logos.  I also have some French Darios made by Amperex that are excellent.

USN CEP's are the ideal sounding 6922 tube. A few on ebay right now.

Those and the JANs were the Navy tubes I was referring to.  I managed to stockpile quite a few about 5 years back.

A lot of Siemens stuff was made in Germany alright , East Germany.
Not that they sounded bad , but often did not last long . .

If you find real Navy tubes, not JAN , they were the best ever made .
Good luck finding  them though .

To my ears the Matsushita tubes suggested above are no better than new production JJs.

Might take a look at Mazda 6922 (Brent Jesse carries them)

Totally disagree about the Matsushita/National 7DJ8 tubes. I have both the new & old JJ's and the National's sound much better to me. They even replaced my reference Valvo Cca's. 

Here is a little about my gear.

I have a Mirus DAC, I would characterize the dac as being very aggressive with details, if it wasn’t for a preamp tube stage, it would be too much for me.

For preamp I use a Pathos aririum, I would say this preamp tries to enhance the sweet spot for all tubes, all tubes sound great on it, unlike some preamps, that sound terrible when you put in some not so great tubes.

That is pretty much the combination that I like, in terms of balance of sound that I like. The tubes really soften up the dac.

The rest of the chain is a solid state amp from audio source and run a set of ADS L620, the speakers were also recap using Jetezen Superior, which retained the qualities of the speakers. I also run a pair of subs.

The speakers are two way, acoustic suspension design. I find two ways even though it lacks detail, compared to systems with more drivers, creates the best imaging. I also like the sound of paper woofers, for the tonal qualities they produce. They are also one of the more non fatiguing speakers, because I listen to music about 4 - 6 hours daily, sometimes 8. I also listen to music about 60-70 db most of the time, and when I am feeling it push it to 80-90db.

So that is how my gear is assemble to produce the most natural sound.

The CCA are really great tubes, and I think I will still keep them, but I just can’t turn them up all the way up. They work well at low levels and I can listen to them about 2-3 hours a time, before fatigue sets in.

Prior to the CCA my favorite tube was the telefunkens, they were razor flat in presentation too, but eventually I didn't like the rounded out bass, it didn't sound natural to me. The CCa now have issues on the other direction, I love what it does to instruments that reach highs, really give strings that sizzle, but my ear's can't handle them for extended periods. They do sound magnficent for the 1-2 hours i listen to them for. 

Nice digital system! The CCa tubes are really revealing units. Basically you have upgraded up to the point that you are hearing the true nature of the sonics of your DAC, the AC power that is feeding it, and the files/discs it plays.

EMI and RFI are enemies of the character of a DAC's highs. Every time I have used an EMI/RFI line power filter on a DAC the digital glare calmed down. I highly recommend you try one on your DAC.

Here is what I am talking about, 

http://www.newark.com/te-connectivity-corcom/10et1/rfi-power-line-filter-10a-500ua/dp/52K4501  

There are much smaller filters available but the one I link is vastly overrated so it will pass current freely to your DAC. 

The problem is that it has to be wired into you power line feed to the DAC. I have always spliced them into an IEC power cord or a normal power strip. 

There are plug and go solutions like Furman but the filters in those are not nearly as strong as the Corcom I linked.

Every time I have used these I have never regretted it.   

A second or third vote in support of the Matsushita/National 7DJ8 tubes, I dropped 6 into my preamp about a year ago and they sound excellent. I would characterize the sound as more neutral than warm, with excellent detail. Not sure they are what the OP is looking for but an excellent tube and superb value.

I haven’t rolled 6dj8 equivalents in a long while, but I preferred to Tele to the Siemens, even though the Siemens was probably the more linear tube, the Tele sounded more 3d in the mids. I suspect it was the character of the circuit. I think the "right" tube for you is perhaps even trickier since you are compensating for the aggressiveness of the DAC.
Brendan at TubeWorld, already mentioned, has a pretty good handle on the sound character of NOS tubes and as I recall, he does allow a return.
I’ve used him for years and he’s proven to be a reliable supplier.
I struck gold recently with the Tubemonger- he had some NIB Genelex (GEC) EF86 tubes that were flying lead types that he converted to "normal" tube pin bases. These complement the GEC KT 66 power tubes that I got from Brendan (not easy to find either) for a pair of vintage Quad II amps. I’d reach out to both shops and get some advice.
I roll very little in my main system these days-- the odd rectifier for the phono stage, and one small tube--a 12ax7- in my power amps. I’d say any advice regarding a particular tube will be in a vacuum (sorry) given the balance you are trying to strike.
Out of curiosity, do you have another source that doesn’t use the DAC- and did you reach similar conclusions regarding the tubes you’ve tried so far?

So for power I found power supply with some type of toroidal transformer to be cost effective enough, the preamp has a lps, and the people who design my dac went really far and wrote a white paper a few pages and talked about the effort they put to clean the power. 

The issue pretty much goes away with a switch of tubes. I'll try to change sources and see but I'm pretty sure it's the tubes. 

I got some tube recommendation and ill give it a try. 

All things aside, my favorite tube in the 'J8 family is the GE 6dj8 smoked glass. Rich midrange, yet not bloated. I will do tweaks around them to bring out the top end they lack. That's how good I think they are. 

Now don't ask me about the time I was at a surplus place and pulled out a drawer of about 20 Matsushita CV2493 and only bought 2 at the paltry sum of 1 dollar each!   

Good luck on your search.   

I should also note that the dac is aggressive not in tonal qualities but just sheer amount of detail it is able to retrieve. It sounds like hd tv would, you see eveything but it in an artificial way. The tubes blend the sounds together to one coherent sound. If I bypass the tube stage and just dac to amp I don't have the issues.

At this point give Tube World a call and ask them about this,

 " 6DJ8 Amperex Holland 1958-1959 "D" getter halo (the rarest and most sought after 6DJ8, very lifelike sound) (oldest and rarest 6DJ8 Holland in stock) (these are the best 6DJ8 to use in a linestage, more musical than CCa Telefunken) (6DJ8 Holland sound excellent in preamps by AR, CJ, Audible Illusions, Sonic Frontiers, VAC, CAT, etc.) (HEART tube CD player) Customer Comment: ---------------- "All my absolute favorite 6DJ8's are made in Holland. They have the rich midrange that I love."  

Lounge- are you Morinix over on the Hoffman forum? If so, nice to see you here. 

Hi Whart, Yes this is Morinix from Steve Hoffman's forum (also Morinix at Audio Asylum). Thanks for the welcome! Interesting place here at the 'goN.  

I was able to get a set Matsushita/National 7DJ8. Since it got so many recommendations and very reasonable priced. 

I want to say it did solve the issue of glaring highs that I experince. The first thing that hit me about the tube is that nothing stood out. The highs were clean and the lows were tight. It is defintlaty a good tube. It might lack the "magic" distortions that some of the other tubes are known for. Sometimes that magic leads to fatigue, or just draws too much attention to themselves after extended listing.  But there is no fatigue that comes from them, they are at the hint of warmth. They are what I am looking for and might end my search. 

The bass is not as quick and clean as some of the tubes I've tried, but I think it gets the balance of what a tube stage should do, to add back a sense of naturalness to the music. Very intresting indeed. 

I'm always looking for authentic telefunken, mullard, or amperex, 6dj8 (variant) tubes. They are really getting expensive now however. I'm currently running telefunken in my preamp & amperex in my phono amp. It sounds fantastic. As far as a budget 6dj8, try a sylvania. They are not as good as the ones I listed above, but are pretty cheap in comparison. I like them better than the russians, & they are not that much more expensive.