[akarise]

So I recently splurged on an Amperex 7308 PQ (early large halo getter type, white lettering, Valvo branded, made in Holland, early 1960s) for my Project Ember. Although it hasn't been broken in yet, it is already a noticeable improvement over my Amperex 6DJ8 (white lettering, made in Holland for HP). There is a great deal more detail and soundstage is a bit larger. I'm noticing small nuances in the music that I couldn't hear with the 6DJ8. Imaging is crystal clear with the 7308 and everything is so defined throughout the entire sound spectrum. Noise floor has lowered to the point where it is basically inaudible unless you really try to hear for it when no music is playing. Vocals sound absolutely beautiful and everything just sounds so natural.
 
I'm listening out of an AD2000X, with a Geek Out 450 as the DAC.

 

[Johan-71]

If you like the Russian tubes you should try
6H23P-EV.
If you liked the sound signature of 6n2p
you probably gonna appreciate that too.
And if you have the supercharger, try 6n6p.

Using a 6n2p in E with SC VERY NICE similar to 6nip but more fleshed out sound. These Russians are not expensive. Give one a try. Garage 1217 has some

 

[ericr]

So I recently splurged on an Amperex 7308 PQ (early large halo getter type, white lettering, Valvo branded, made in Holland, early 1960s) for my Project Ember. Although it hasn't been broken in yet, it is already a noticeable improvement over my Amperex 6DJ8 (white lettering, made in Holland for HP). There is a great deal more detail and soundstage is a bit larger. I'm noticing small nuances in the music that I couldn't hear with the 6DJ8. Imaging is crystal clear with the 7308 and everything is so defined throughout the entire sound spectrum. Noise floor has lowered to the point where it is basically inaudible unless you really try to hear for it when no music is playing. Vocals sound absolutely beautiful and everything just sounds so natural.

I'm listening out of an AD2000X, with a Geek Out 450 as the DAC.

Interesting. The Amperex 6DJ8 is one of my top 5 favorite tubes so I might have to get a 7308 to try. How much did yours set you back?

Also, how are you liking the GO 450? Do you have any other DADs to compare it to?

Thanks!

 

[akarise]

Interesting. The Amperex 6DJ8 is one of my top 5 favorite tubes so I might have to get a 7308 to try. How much did yours set you back?

Also, how are you liking the GO 450? Do you have any other DADs to compare it to?

Thanks!

 
I spent $175 and got it from Brent Jessee at audiotubes.com. I know it's a ton to be spending on a tube and I think it's possible to get the white label 7308 PQ at cheaper prices but Brent is a wonderful guy to deal with and very knowledgeable about tubes. I guess I paid in part for the peace of mind that I was getting a totally authentic and tested tube. Totally worth it and I don't plan on getting other tubes so just went for the best I thought I could get instead of buying tons of cheap tubes.
 
The GO 450 is amazing. It's very detailed, spacious, and well balanced with a very slight hint of warmth in the lower frequencies. For what I paid, it was a huge bargain. I only have the GO 100 and HiFimeDIY Sabre DAC to compare it to. The GO 100 is basically the same thing but for IEMs and the Sabre DAC doesn't even come close to touching the Geek Outs. It sounds thin and isn't as 3D in comparison to the Geek Outs. I heard my friend's DX90 the other day and the GO 450 held its own against it.

 

[ericr]

Thanks!

 

[akarise]

Yeah np!

 

[ericr]

OK, I now have about 15 different tubes for the Ember and thought it was time to give some feedback to this thread.  Work is really busy and my daughter is getting married this weekend so no time for a detailed multi-tube review right now so instead I thought I'd post a bit about my favorite tube so far.
 
Close competitors:
 
Raytheon 6QF7/6CG7
Amperex 6DJ8/ECC88
Sylvania Gold Brand 6201
Mazda 4-Star 12AT7WA (a really nice tube that might have won if it was a bit lower gain)
 
Winner:
Westinghouse Carbon Plate 12AU7A
 
Learned about these here: http://www.tubemaze.info/westinghouse-12au7-carbon-plates/ .  Found a good deal on a pair on ebay with the Conn label.
 
Overall:
This tube is a bit toward the warm side without sacrificing detail.
 
Bass:
Nice deep bass extension, tone and impact. No mid-bass hump or bleed into the mids. Good texture and detail.  Doesn't add bass that isn't in the recording, however it does bring out all of the bass in a recording.
 
Mid Range:
Rich and sweet, without sacrificing texture and detail.  Excellent for strings and gives realism to the piano beyond my other tubes.  Male and female vocals are clear, forward and.well, rich and sweet.  The combination of warmth and detail makes for some mice guitar distortion, too.
 
High End:
While a couple of my other warmer tubes suffer from considerably rolled off treble, it's not a problem in this case. While the highs don't have the "wow" in your face nature of the Mazda, if you listen you find they extend nicely and the tube delivers considerable high-end detail.  One added bonus is the almost complete lack of sibilance.  Cymbals are very clear and natural sounding.
 
Soundstage:
Wide, tall and deep.
 
Presentation:
Open, airy, and very realistic. Good instrument placement and separation.  Room resonances are impressive on well done live recordings (i.e., Amber Rubarth's Sessions from the 17th Ward).
 
 
Configuration:
FLAC > Foobar > ODAC or Uber Bifrost > 1964 Ears V6-Stage (also, Beyer T90 and Earsonics SM64)
Note: the V6-Stage are soundstage and detail monsters and it's nice to find a tube that let's the Ember drive them to their best.  Also, it's my opinion the solid state section keeps the Ember very fast and prevents warm tubes such as the Westinghouse from rendering the sound as slow or mushy, which serves to preserve details (low to high).
 
-Eric

 

[GrdironTrenches]

where can 12AX7VKA Russian tube. is it listed on Project Ember website

 

[karnakhawai]

HI...i am michel, member of french's TELLEMENT NOMADE site..
I am looking for a russian "sunrise " 12ax7vka tube, and it is very difficult to find it...garage1217 as none...cedist told the same..and i look everywhere to buy one, but still unsucessfully.
This tube is to be tested on my project ember +AKG K712...like ASR did it on his review..
Any help to find one will be so much apreciated..
Thanks

 

[nykobing]

Don't be so worried about finding that 12ax7vka tube. I guess you read this part of his review, "The 12AX7VKA had it all over the other tubes when it came to driving specifically the K712." That is going to happen with any 5751 / 12ax7 tube and most any NOS tube will wipe the floor with that newly made Russian tube. The best in the 5751 / 12ax7 tubes I have tried in the Ember is actually a French tube, a Mazda 5751, it has more detail than my Sylvania 5751 black plate triple mica, which is my second favorite. The GE triple mica black plate is great as well. I have only tried a few 12ax7s, but they were a lot noisier than the 5751s.

 

[karnakhawai]

Thanks a lot nykobing...your reply is a good help to find the best tube to drive my akg k712...i will be looking for that mazda 5751.
It's true that the asr comments on k712 + ember + 12ax7vka...started my quest to find that tube, and i am sur i will find one later, as i realy want to hear that...but i will certainly buy some others tubes as well, and your recomendations will help me a lot...just expecting that the tubes you mention, are not as difficult to find as the sunrise and not too much overpriced...
Thanks again

 

[Asr]

I am looking for a russian "sunrise " 12ax7vka tube, and it is very difficult to find it...garage1217 as none...cedist told the same..and i look everywhere to buy one, but still unsucessfully. This tube is to be tested on my project ember +AKG K712...like ASR did it on his review..
Any help to find one will be so much apreciated..
Thanks

 
Don't bother looking for a 12AX7VKA, I was told by Garage1217 that it's a rare tube and it was from their personal collection. The only reason it was included with the Project Ember review unit was to offer a high-gain option for driving inefficient headphones. Many other high-gain tubes would also work, ask either here on the forum or Garage1217 for advice. I have no experience with any other tubes and can't offer any info either. Btw, sorry but I don't respond to PMs for personal reasons. If you have any follow-up questions, please post here in the thread instead and others will also be able to help.
 
It's likely that you'd get similar or even better results with another tube, as nykobing mentioned. I even mentioned (twice) in the review the Tung-Sol 12AX7 as a possible alternative, did you miss those mentions?
 
I just updated the review with a note on the rarity of the 12AX7VKA btw, since both you and GrdironTrenches posted that you were looking for one. As advice to everyone, don't bother trying to look for a 12AX7VKA, very unlikely one would be found anywhere anytime soon (and even if one showed up, I'd bet it would be very expensive). And just because I used it doesn't necessarily mean anyone else should, regardless of what I wrote about it. There are so many varieties of tubes available that it's more likely to find something that would sound even better anyway.

 

[karnakhawai]

Thanks a lot asr, for your reply...i will end now, my quest for sunrise 12ax7vka...if it's so difficult to find.
Jeremy told me to use an 6n2p, and i allready bought an 6n2p-ev..that is very similar ( but not yet tested)...
Well i will for sure buy some other tubes, following feedbacks on headfi an french TN...
I am sorry for the mp, asr...will post directly on apropriate treads...
Have a nice day...

 

[zoolzoo]

  Has anyone tried an Amperex 7308 white PQ shield type tube with their Project Ember? I'm currently using an Amperex HP 6DJ8 with white lettering made in Holland but I'm thinking about upgrading to the 7308 in the near future.

 
Wondering the same thing. I have the white label 6DJ8 and Orange globe, and I like them both at this point. The last tube I was thinking about picking up is the 7308.

 

[akarise]

   
Wondering the same thing. I have the white label 6DJ8 and Orange globe, and I like them both at this point. The last tube I was thinking about picking up is the 7308.

 
You should go for it! A noticeable upgrade. I posted a comparison a few posts earlier about a week ago.