[geetarman49]

Quote:

geetarman49 Is it possible that what I described as a "sloping square getter" is in fact a D getter. I have also seen these described as "mid 1950's...14 mm black plate tubes with angled bent rectangular getters."

i have both rectangular- & d-getter type tubes, not all 12au7 of course - those getters look physically different.  wrt the cbs hytron, it seems that the rectangular getters  can be found with both angled and straight, horizontal arrangements, but i don't know if this makes any difference in terms of sonic quality.  a careful side-by-side comparison of several instances of each type would be req'd to confirm.

 

[geetarman49]

Quote:

Just won a pair of RFT 12AU7's on eBay for $20 plus $9 shipping to try out in my Project Horizon.
 
Still waiting for my TJ Fullmusic to come too. I'll report back when they come.

old stock rft's should be quite good; let us know how they sound.

 

[chinook9]

Well guys, I did it today. I bought a Telefunken 12AU7 smooth plate (possibly used) for $48 from Brent Jesse and followed up by bidding on a pair of Amperex 6201 gold pins which I won for $67. I couldn't tell if both the 6201 were marked Premium Quality but one of them was. I don't know if it makes any difference actually, but I will find out.

 

[bluemonkeyflyer]

I ordered multiples of NOS/NIB Tesla E88CC, Amperex Bugle Boy Gold Pins, Telefunken PC88, Reflector and Voshkod 6N23P/EV, Tesla Crossed Swords, Siemens E88CC, mixed 12AU7 and 12AX7, Psvane 12AU7 and 12AX7, Sophia Electric 12AU7, RCA 12AU7 Clear Tops, and mixed 12AV7 and 12BH7A tubes. Gonna be fun to try and send out to others to try with garage1217's Superb Project Sunrise II Amp.

 

[chinook9]

I ordered multiples of NOS/NIB Tesla E88CC, Amperex Bugle Boy Gold Pins, Telefunken PC88, Reflector and Voshkod 6N23P/EV, Tesla Crossed Swords, Siemens E88CC, mixed 12AU7 and 12AX7, Psvane 12AU7 and 12AX7, Sophia Electric 12AU7, RCA 12AU7 Clear Tops, and mixed 12AV7 and 12BH7A tubes. Gonna be fun to try and send out to others to try with garage1217's Superb Project Sunrise II Amp.

 
I'm looking forward to hearing about all these tubes... and maybe trying some. How long do you plan to burn in before you start making judgements. I've settled on 30 hours, but I'm not sure that's enough. The burn in made a great difference to my CBS Hytron 5814. That is one nice tube.

 

[geetarman49]

grant fidelity recommend 100hr for the psvane if i'm not mistaken.
 

 

[geetarman49]

Quote:

Interesting you mentioned Psvane tubes, chinook9. ... They only come in pairs but I suppose I could sell one. ...

inquire with the seller ... often, singles (without box) may be available.

 

[Micaiah]

Quote:

Interesting you mentioned Psvane tubes, chinook9. ... They only come in pairs but I suppose I could sell one. ...

inquire with the seller ... often, singles (without box) may be available.
 
Thanks geetarman49, good idea.
 
I got my TJ Full Music 12AU7 yesterday. To burn in a tube, is it necessary for a source to be providing a signal (like music) or will just having the amp on be sufficient? 

 

[l0rdr0ck]

Just got in some Japanese 12AT7 tubes,  lucky me included in the lot were 2 Marconi super-rare made in Japan tubes.
 
And i found some GEC B309s,  i guess we should have a flood of tube reviews soon!

 

[Modular]

Just got my TJ Fullmusic from China the other day. It needs some more time to burn in of course - initial impressions were that it was really bright, but after literally an hour, that calmed down and it's settling into a really nice sound. More bass I think than the stock tube, which I'm happy with. Not only that, but the bass is more "defined" I'd say - cleaner. More to come from these novice ears once I get some hours behind the tube

 

[chinook9]

I expect that you really need to run a signal through the tube. I have used music, but now I've started using a freeware program biwavegen and I run pink noise at a somewhat high volume and I use some old headphones as the load. If you can't find biwavegen to download, just PM me and I'll send it to you. Its only 45Kb.

 

[Micaiah]

Thanks for the answer and offer chinook9; pm sent.
 
I figured that tubes would probably need a signal to burn in effectively. I don't like to leave my electronics on while I'm gone and because my headphone rig is by my bed, 24 hour/day burn-in doesn't work out. Maybe the pink noise generator wont bother me at night. Might even help me to fall asleep!
 
The Rft 12AU7 still isn't here but the TJ Fullmusic 12AU7 has about 35 hours of music burn-in. I'll wait for the RFT to arrive to do a serious comparison but I do have to say that so far I've learned something very important. Tubes need more that 5 hours to burn in! Kind of a duh moment. I know the importance of burning in headphones (AKG K702's!), speakers, interconnects, DAC's, etc. so it should have been obvious. Guess there was a little bit of fear of burning out a tube prematurely by leaving it run for days.
 
If I hadn't been swapping back and forth between the new TJ and the Tungsol 12AX7 cryo'ed gold pin (many hundreds of hours on it), I might have chalked the improvements in the TJ up more to my imagination or 'ear-burn-in'. By swapping back and forth and comparing the two as the TJ increased in hours, it was obvious that the TJ was improving quite a bit for the first 20+ hours. New out of the box and with less than a minute on the TJ it lacked soundstage depth, the treble seemed glassy and too forward and bass wasn't as tight and it was fatiguing to listen. To my ears, if the Tungsol = 100, the TJ = 70. After about 25 hours the TJ = 95. It's so close now that I don't know if I could tell the difference in a blind test but I'm still getting the feeling that I like the Tungsol a little more. It seems slightly more extended in the highs and sounds punchier in the bass region. Hard to say when swapping out tubes, adjusting the bias and then accounting for one tube being colder (temperature) than the other takes long enough that the audio memory has faded some. 
 
I hate to say it but I don't think I gave other tubes enough of a chance to burn in. I think the $40 NOS tube I bought about a year ago (came in an RCA box) probably got less than 5 hours of use before I decided it sounded too veiled. The 6N23P that came with the Project Horizon may not have gotten much more than an hour. Maybe I should try putting some more time on the 6N23P and see what happens. 

 

[chinook9]

   
Micaiah
 
I have attached what you need to this posting.

 

[Micaiah]

Thank you, it works great! I have Biwavegen running now with pink noise through the 6N23P tube.

 

[chinook9]

Great!  I use a set of earbuds as the load and put a pillow over them.  Can't hear a thing.