2. amps-preamps
  3. 153588-136265

12BZ7 ///12AX7

Could not finda  topic for tubes, so am using amps section.
After making the amazing discovery of the E80CC as sub for AU~~E80CC blows away every/all AU's, including the *Holy Grails/Siemens,Tele's*.
http://www.r-type.org/exhib/aaa0426.htm
at least in my Defy7, the swap was more than just significant, the Defy came to life from the grave.
I found the Siemens to bea  miniscle superior to Philips = both are equal IMHO, and the valvo Red label E80's going for $$$$$$$$$$ is a scam. Don't buy into it. 
Right now that tube  is going for $50/each. When word gets out  ~~Super Tube~~~the price will rocket, as that tube is not being produced any longer. 
I've loaded up on the Philips label.

so i figured,, maybe there is a  
~~Super Tube~~ for the AX..
After days/weeks of research,,i found this
12BZ7
https://www.radiomuseum.org/tubes/tube_12bz7.html


*Big Boys*
So  ordered a  bunch off ebay, and will arrive next week
Will post a  review.
can not find much on the INET about the 12BZ7,, anyone have experience with this tube?
mozartfan
mozartfan OP
2,143 posts
 
Yes 5751, horrible, 
I am bidding on  a pair of Tele, 16 hrs left,,I am winning at $81,,,tubes pulled from a  estate sale, working ociliscope, look NOS 100%, I am at top $, doubt i win. 
Might try in 2 yrs to pick upa  pair.
chinacat
1 posts
 
I have tried Mazda 12AX7( S) silver plate with Sylvania 12BH7(A) in my Rogue Apollo’s upgraded to Darks at factory, actually on Mulveling’s recommendation. I am very pleased with the results. Currently, I am using  Mazda 5751 silver plate 3mica and like them. They sound more revealing, albeit not as quiet as the silver plate 12AX7S. I understand it’s a matter of personal taste, but am I missing something here?
mulveling's avatar
mulveling
1,913 posts
 
@chinacat
The 5751 silver plates, as you mentioned, are very revealing. However in my system it was revealing to the point of being BRUTAL. Including an excess of high frequency energy. I liked the effect for up to 30 minutes at a time, but then it became too fatiguing to continue. The 12ax7 had the better, more natural balance. However the 5751 was very exciting at first, especially with certain recordings.

Then, of course every system and set of ears is different! To add some context, my Tannoy Canterbury GR speakers often don’t do well with upstream gear having any excess treble energy. I am glad you enjoy the tubes, regardless!
oldhvymec
5,101 posts
 
Wow what a roller coaster. Fun to look at, but sure a lot of it..

Your on quit a journey indeed. "Burn in Theory" Take a little more time and let the things break in a bit, settle down. 

I'm reading some pretty crazy stuff here. Cables were swapped?

How may valves sounded bad during that time? How long were they that way?

I have quite a few different "TANKS" as you call them here..
Be careful. A valve can really cause problems.  You have a way to check your valves and make sure they are balanced? No issues to begin with. That's probably most of the issues with "sound bad" valves.  Like I said, a lot of words, but difficult to weed through it..

No lack of enthusiasm though..

Regards
More to discover