2. tech-talk
  3. 1232169994

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
bicycle_man OP
100 posts
 
Actually I found the upper frequency detail softened and veiled by the Telefunkens in my system compared to Bucgle Boys and Mullards, including the 10ms.

This is with my Fisher 400c and Dynaco Pas3x pre-amps.

I did not have muddiness with the Tele's, just not the same upper frequency and timbral magic of the BB's and Mullards. Also, the latter two brands were more open and had wider and deeper soundstaging qualities.
rodman99999
6,035 posts
 
Which Tele's did you try Mr B?
bicycle_man OP
100 posts
 
Hi Rodman,
They came with my Dynaco pre-amp. I bought it and a Stereo 70 from the son of an engineer who made it while he was in college in 1965. I don't believe he ever changed the tubes. The tubes test very well in my tube tester.

The tubes have the diamond in the glass inside the semi-circle of pins. There are number codes inside the diamonds (date codes I guess).

I have long since rubbed off the lettering while cleaning the tubes with isopropanol. But the diamonds are of course there as they are molded in the glass.
nsgarch's avatar
nsgarch
2,524 posts
 
I know none of you will believe this (until you try it!) but the best way to clean tubes, and especially European tubes with that delicate white printing, is naphtha (as in: Ronsonal lighter fluid.) Anything with even a hint of water in it (almost all alcohols, Win dex, etc) will dissolve the white paint, but not naphtha.
bicycle_man OP
100 posts
 
Now you tell me! After I washed off those cool little bugle boys off my Bugle Boys! Should I just toss them and buy some of those more robust Bugle Boys where the bugle boy doesn't wash off?

Thanks for the information! I will give it a try.
More to discover