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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
 
Bob, "ruggedized" (for the military) 5751's (especially the triple mica ones) are supposed to be great in phono and microphone preamps because of their extremly low noise and/or microphonics compared to a regular 12AX7. Something I can't really judge as mine are in an amplifier. However, they are definitely smoother (by which I mean less in-your-face grainy) than the 12AX7's I've tried; and the really good 5751's are more dynamic too. -- Neil
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galyons
1 posts
 
Bob,
Jim H, most likely doesn't recommend 5751's in the Trumpet because the RIAA is passive and the tubes contribute to the equalization. That being said. I am no RIAA equalization
Nazi and use 5751's, which I think sound great, in my phono pre amp. I am building a Cornet2 and will try them there, well.

Cheers,
Geary
ptmconsulting
1,000 posts
 
Update, I had some good ears over this past weekend and we played with a few different things. We did try swapping out the 5751's for the Tung Sols.

The impression was that the RCA Black Blate 5751's were a bit more dynamic but ultimately too plummy and slower on the bottom end. The Tung Sol 12AX7's were clearer and cleaner and faster all around. The general consensus was to leave the Tung Sols in.

Well, that's what this hobby is all about. Trying different things from time to time, but making sure to go back and see if a change is ultimately an improvement, or just a change.

Enjoy,
Bob
bicycle_man OP
100 posts
 
Some POS from Singapore is trying to sell a pair of NOS ECC803S's for $1099.99 + shipping.

http://cgi.ebay.com/2XNOS-ECC803S-ECC83-12AX7-Telefunken-Bottom-Ulm_W0QQitemZ130310286752QQihZ003QQcategoryZ67816QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

MoFo!
nsgarch's avatar
nsgarch
2,524 posts
 
Bicycle_man, isn't that queen just too much!? It cracks me up every time I see his auctions!

Bob, I applaud your reminding us all of this:
. . . but making sure to go back and see if a change is ultimately an improvement, or just a change.
Human beings being the stimulation junkies we are, changes often seem 'better'. For at least a minute!!

Geary, I have also been cautioned about using 5751's if they would be in (active) RIAA circuits. Apparently passive RIAA circuits are not affected.

Neil
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