6dj8 tube comparisons in dodd elp

marvda1

if you have experience with any of the following tubes used in the dodd elp please explain.

amperex orange globe
amperex bugle boy
electro-harmonix eh gold pin
jj tesla
jan philips green letter
jan philips blue letter

scottyf

I have a Counterpoint 3000 modified by Altavista Audio that has 3 6dj8's -- one in the line stage and two in the phono. Here are the tube's I've listened to:

Amperex USN-CEP 7308 -- my absolute favorite. It has an amazing ability to make things sound alive! Great bass, extended highs, wide but detailed soundstage and a vividness that no other tube I've heard posesses. I like this one so much I sold off all my backup stereo equipment to buy as many of these as I could lay my hands on. At $80-150 a pop, they aren't cheap. I've heard that the Telefunken's are better, but I can't afford them. (I didn't think I could afford the USN's, but somehow I managed!)

Siemens 7308 (RCA Label) -- more neutral than the USN, less of the glow. Excellent bass and top end extension. In my system, not as wonderful as the USN, but in another one, I could see it being the better tube.

Amperex Orange Globe 6dj8's -- soundstage is not as big, but a little more focused than the BB. A warm, put-together sound with good balance from top to bottom.

Amperex A-Frame 6DJ8 -- very much like the Orange globes. All of the ones I've gotten have been low in microphonics, perhaps because of the whole A-Frame design.

Amperex Bugle Boys 6dj8's -- same soundstage as the USN's but less focused. Not quite as vibrant a sound or quite as deep in the base. Still very, very good.

Matsushita 6922's -- I got these from Musical Concepts and they are very nice. Warmer than the Amperexes, but not as information in the high end. Much better than any thing current, but not quite up to the Amperex and Siemens.

Jan Phillips Green 6922 -- compared to any of the above tubes, not good. Soundstage is ok, highs are kinda muddy and bass is ok. Detail and color is missing from this tube compared to the Amperex's and Siemens.

Overall, I prefer the Amperex sound. Orange Globes and A-Frame 6DJ8's are not too expensive on Ebay and Audiogon. If you want to hear what the next level sounds like, score a set of Amperex USN-CEP 7308's from the early to mid 60's. They will rock your world!

Here's another website with info and pictures about 7308/6922/6DJ8's. The info comes from Joe's Tube Lore on Audio Assylum, though he is not credited. The pictures are important because there are so many scammers out there.

http://spazioinwind.libero.it/themagicsound/_private/elenco_produt_eng.htm

Anyways, that's my two cents....

organ

Scott,
Wow, excellent descriptions. I also like my Ampex 7308 best.

You should give JJ a shot. It sounds like a Mullard 6DJ8 on steroids!

Do you find 6DJ8's to have limited dynamics compared to 6922?

Maurice

scottyf

To be honest, no. Or maybe I'm hearing what you describe as dynamics. The USN just sounds more like the real thing, be it sax, guitar or whatever. Just the right amount of bite of the string pluck without losing any of the warm resonance of the body. To me, the USN is much more vibrantly colored and alive....kinda like the difference between a normal TV broadcast and an HDTV one.

When I was rollin' the tubes, I could never get any Mullards at a reasonable price. This is why I don't really have an opinion of them.

I took some recommendations based on what I read initially, but in the end, I had to listen to them. Most on the internet would prefer the Holland Ampex 7308's and the regular USA Ampex 7308's, but in my setup, the USN-CEP's just RULE!

I figure I have enough USN-CEP 7308's to retube until I am 73 or so. At that point, I won't be able to afford any more USN's so maybe at that point I'll try the JJ's....hehe.

Scott

organ

Oh I forgot to mention. I meant 7308/6922 vs. 6DJ8. The 7308 is a premium 6922.

So this would be your USN vs the ampex 6DJ8's.

The DJ8's I've tried all have very lush mids and smooth highs but is weak on dynamics/slam compared to 6922.

You're lucky to have a lifetime supply of your fav tube. I need a lifetime supply of Mullard GZ34.

scottyf

Hmm, just read my reply and realized I got off track.

Organ, in answer to your question, no, I didn't find dynamics limited with 6DJ8's. At least not as a class. Some 6DJ8's are lighter in dynamics than others as some 6922's are. I had a chance to listen to a pair of Amperex '60 D-getter 6922's and while they were very euphonic, they also kinda lagged in my system. While I could see why they were revered by many, they just didn't do it for me. On the other hand, I like the Orange Globe Amperex 6DJ8's. I think they have fine rhythm and overall balance.

In addition, you can't really count on the 7308/6922/6DJ8 label. Most "real" 6922 and 7308 tubes have gold pins. However, I have some pairs of (orange labled) Amperex 7308's that I really like that have normal steel pins. Also, all of my Matsushita 6922's are steel pinned as well. One thing you can count on is that because of the military requirement, 7308's will match well with other 7308's of the same kind (e.g.,white label Amperex to white label Amperex). Beyond that, I don't really pay attention to it's designation of 6DJ8, 6922, or 7308.

It has been my experience that each tube (Amp 7308 white label, Amp 6DJ8 BB, Matsushia 6922, etc) has a specific sound. In addition, that sound varies a bit from equipment to equipment. The comparisons I've made have been using my Counterpoint 3000 and my Melos SHA-Gold. Other preamps may sound different.

The best generalization I can make is that the earlier the tube, the better the sound. In addition, the tubes made in the 80's generally suck. It has also been my experience that 7308's don't last any longer than 6DJ8's...at least in the different preamps I've used them in.

My suggestions are just a starting point. Get some and listen for yourself!

Scott

reeltrouble1

Your mileage will very from others depending on your unique system. Good success with the Amperex 6DJ8 in my rig, The Phillips and JJ are also quite good and are very reasonable. Tube rolling is part of the fun of the Dodd. Example one of our long time member feels the Orange Globe is awful.

RT1

scottyf

Very true, reeltrouble1. A very important part of the game is making sure you are getting the real McCoy. NOS tubes are big money so there are a lot of fakes out there. That's why I posted that link of pictures and description for you. If you want a couple of good tube dealers, I would be happy to post links for you.

Scott

marvda1

does anyone know who makes the tube for groove tube? the part number is gt-6dj8.
marvin

dorokusai

www.groovetubes.com

jfb4548

marvda1 wrote:

does anyone know who makes the tube for groove tube? the part number is gt-6dj8.
marvin

Look at UpScale Audio's web page. The have a bit of info on the Groove Tubes cause they sell a GT12AX7M that they get from GT directly.

organ

Groove Tubes have some exclusive tubes designed by GT and built at the JJ plant. They have an exclusive E34L, 12AX7 and 6CA7. They have a Mullard EL34 copy coming out soon.

The GT 6DJ8 looks very much like a Sovtek/EH 6922 but from what I know, Sovtek/EH doesn't make 6DJ8, only Ei does.