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Rolled some 12ax7's recently...

Hi All,
I went through my supply of 12ax7's recently and found some goodies.
I recently compared Bugle Boys to Telefunkens in the phono stage of my pre-amp. Interesting (to me, at least). I found the Telefunkens to be nice sounding; very clean and clear, very nice detail, over all a very nice sounding tube. The Bugle Boys, however, were magical! WOW! Timbre was so much more apparent. The soundstage depth and width increased; especially the depth. The music seemed to come alive and glow. It was much more captivating.
I found such a dramatic difference between two high quality tubes very interesting.
I have yet to try 10m's, and 70's Mullards that I found. I will report when I do...
By the way, NOS Sylvania's sound nice in the line-level stage. All tubes reported are vintage NOS. I match them with my tube tester. And, I do not change the volume setting between tube brands tested.
Any comments are more than welcomed! I appreciate any information on your experiences with 12ax7's. The price of some of these NOS is incredible; I am glad to have these nice examples in my collection!
Cheers.
bicycle_man
nsgarch's avatar
nsgarch
2,524 posts
 
Rodman, I danced around with various 6201's after trying some 'normal' TFK and RCA 12AT7's (which weren't bad actually) and also a quad of Mullard CV4024's (which for some reason I didn't really like; which surprised me after all the good things I'd heard), anyway, I liked the Sylvania 6201's a lot (the 2-mica BP gold pins) but the ones I like best (they're not 6201's) are the GEC A2900 (or CV6091 military designation.) These are amazing tubes; really powerful, but smooth as silk, like Gold Lion KT-88's! I was going to try and put together a spare quad but I think the word has got out (damn!) I got my first pair for $85 six months ago, and now they're over $200!! Check the mutual conductance values on these babies, and you'll see what I mean by 'powerful'! http://cgi.ebay.com/2XNOS-A2900-CV6091-12AT7-ECC81-GEC-Great-Britain_W0QQitemZ140298633321QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item140298633321&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50
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rodman99999
6,206 posts
 
Sounds like me. I should have stocked up on TungSol 6SN7GT/VT-231 Round Plates($50.00 ea, when I fell in love with them) while I had the chance. I was going to use three 6201's as phase splitter/drivers, but gave up on that amp after getting burned by the transformer builder(paid for, never received). Nothing I own now uses 6201's, so- I've never even heard these.
nsgarch's avatar
nsgarch
2,524 posts
 
R -- I know, don't ya just hate when that happens! ;-)
rodman99999
6,206 posts
 
Every time(you'd think I'd learn!). =8^(
bicycle_man OP
100 posts
 
Hi Clipper,
I have the BB 12ax7's in the phono stage, a BB 12at7 nearest the transformer, 2 Sylvania 12at7's near the can caps, and an unknown old stock 7025 in between (near the 6v4 rectifier).

The pre-amp sounds fine on tuner and both aux's, and of course, super fine on phono. I have repaired mine as many of the old Wima caps have dried out and wasted away.

I have also used the BB's in my Dynaco Pas3x and have found the same results as I previously described. The Fisher is not as forward sounding as the Dynaco, but it is, oh, so much sweeter! I was happy to see some Fishers selling on ebay for more than $450 in the last few months! As I recall, one of those was the 400-cx, which has a better following, but the other was a plain old 400-c. I have the 400-c. I like it and can't wait to get my Koetsu re-done -- should be mid-range luscious delight!
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