6DJ8

[miklorsmith]

Nope, I don't have those 6922s.  The main equivalent types are 6DJ8, 6922, and 7308.  The European equivalant designations are ECC88, E88CC, and E188CC.  There are many others.  The 6DJ8 is actually the "base tube" and the others are upgraded, military types.  Supposedly the 7308 is the baddest of the bunch, especially the US made Amperexes.  By that I mean "most stout".  The best sounding are reported to be the Pinch Waist Amperexes from Holland, but these will set you back about $500 a pair if you can find them.

Siemens CCa tubes have a killer reputation but are hard to find, as are all the Telefunkens.  Just about anything from Amperex Holland is considered excellent.  The Siemens tubes often fetch $200 a pair and nice Teles are in that range too.  Of course if you're looking for one tube it should be less than half the "matched pair" price.

Most of the US-made tubes are not considered as good.

There is a lot of information out there on this tube. 

http://www.audiotubes.com/6dj8.htm

http://www.audioasylum.com/audio/faq/joes-tubes.html#6DJ8

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1154646514&openfrom&1&4#1

Of course the circuit the tube is used in makes a significant difference.  The Amperex Holland 6DJ8 Bugle Boy is widely reported to be a great tube and a killer value, you can pick them up for $50 - $80 a pair.  I bought some, they are terrific in the Lamm preamp but terrible and I mean terrible in the Isabella.  They're far worse than the stock JJ tubes which are actually pretty nice.

I also have Amperex Orange Globe 6DJ8s which are really nice in both preamps and generally a killer deal in the $40-ish range per pair.  The Tesla E88CCs are very nice as well, made in Czech Republic.  They run around $50 a pair but I gather these vary some in quality.  I still have some Telefunken 7DJ8s arriving today and a pair of US Amperex 7308s which should be here any day.  They both stand to be excellent but are a little more expensive.  Going rate for both types is around $120/pr.

Like any NOS tube, this family is like a rabbit hole, you get into it and the tunnel goes and goes.  There are lots of types I haven't mentioned and there also significant variations within types from individual manufacturers.  Some of the types are reported to be victims of forgeries and sales as "authentic".  It's fun to play though, especially if you don't get into the stratospheric stuff. 

[richidoo]

Thanks for all your help on the preamp Mike. I would have junked it if not for your encouragement. Now hopefully it can finance a scratcher.

Thanks for the tube tips Mike, I didn't know that 6922 and 6DJ8 were same. What 6DJ8 type is:

"...alive w/ a little warmth and not too bright."

[Carlman]

I'm using one of the super nice Siemen's now.. but I don't really care for the character.  I even had it cryo'd.. It's a great tube... It just seems a little more focused on the highs and less so on the lower mids.  I had a matched pair but 1 got hosed in the cry process.  I can't find my tube stash at the moment... So, I thought I'd poke around for 1. 

I've used Amprerex in the past but they vary widely from year to year, batch to batch, etc.  They are alive and with a touch of warmth in my experience but the highs were less refined than the Siemens.

BTW.. The EE phono pre uses 3 12AX7's.. but I think I have some EE 12AU7's in my stash if I can find it.  I probably only have 2, though.

[miklorsmith]

You might look for one of the US-made Amperex 7308s.  Supposedly the 7308s are extremely consistent batch-to-batch and the US Amps are best of the bunch.

Or, you could look for a Telefunken.  They're spoken of in hushed tones, _{maybe I should write a little quieter}.   

[miklorsmith]

Yep, that was a wee bit OT.     Hey, I can go back and update the original post if I can get back into it.

[richidoo]

Here you go: http://www.audionervosa.com/index.php?topic=1139.0

[miklorsmith]

Whoops, I meant fix the new 6DJ8 initial post.

[rollo]

I'm using one of the super nice Siemen's now.. but I don't really care for the character.  I even had it cryo'd.. It's a great tube... It just seems a little more focused on the highs and less so on the lower mids.  I had a matched pair but 1 got hosed in the cry process.  I can't find my tube stash at the moment... So, I thought I'd poke around for 1. 

I've used Amprerex in the past but they vary widely from year to year, batch to batch, etc.  They are alive and with a touch of warmth in my experience but the highs were less refined than the Siemens.

BTW.. The EE phono pre uses 3 12AX7's.. but I think I have some EE 12AU7's in my stash if I can find it.  I probably only have 2, though.

You might want to try Sophia electrics 12Au and AX 7s. Hearing a lot of good comments on them .


charles

[richidoo]

Or the TechTubes, if/when you can get them. From what I read they are completely new tube designs, based on recent CRT advancements at the Mullard factory. It is like a little TV tube, very focused electron beam, very small parts inside. Same spec, but much higher performance.

AX7 is available now, I think AU7 is coming next. Not cheap
http://www.techtubevalves.com/

[rollo]

What about $50 each, not bad. The Sophias are $120/ matched pair. NOS can fetch up to $300/ pr. these days. Anyone tried them yet ?
   Right now I'm looking for 5687s, Mullard that is. picked up some CF Thompson 5687s so far very impressed full rich and detailed. This brand is new to me made in France.



charles