2. tech-talk
  3. 159701-136265

Newproduction power tubes: Reliablity

There  isa topic going on  concerning power tube issues in his PL amp, 
Some of us have power amps with 4-12 power tubes,,  the higher number of the tubes in a amp means the more demand for  reliability.
The 2 countries making  the most power tubes are china and russsia, So basically we can say this is a Russia vs China shootout.

China has come out with incredible numbers of power tubes, varieties and styles. These are the SET tubes. Russia has a  far superior selection in the push pull category.
IMHO , as i do have a  push pull amp, I favor the russian labs as far as reliability. 
Here is where it counts, As we know, its no fun having a   multiple power tube amp, and hearing 1 or more tubes going bad. 
A  good tech is not cheap, nor so easy to locate.
So in terms of reliability/push pull, I have to side with the russian labs.
The one exception on russian power tube relaibility, is the russian KT150,, its a new tube and we have not yet had long term performance testing. It is  not a tube I am the least bit interested in. 
. 

mozartfan
mozartfan OP
2,143 posts
 
From the Russian side, the GL KT8s are my favorite
^^^^^^^^^^


I had that tube, sent it back witha  generous restock fee, vivtubes says *thats the 2 nd matched 12 power tubes sent back in 1 month,,shop elsewhere please...*,,, anyway,, odd that my opinion was in line with another comment i read on a  forum (audio karma??)about the GL. Very popular, but he and I were in same opinion.


mozartfan OP
2,143 posts
 
PSVANE T-II 12A_7 series.

^^^^ 
I have 2 pairs of Psvane's 12AX7's in boxes, really nice boxes,,, I am willing to dump at any price,,, i'll take 50% of what i paid,,,, good riddance....
China, nor russia can make a  good(=read GREAT sounding)  pre tube. 
The best pre tubes were made by Telefunken. 
hilde45's avatar
hilde45
4,974 posts
 
I  just ditched my JJKT 88‘s for Genelex kt 77‘s and the difference is quite startling. The JJs didn’t sound very good in comparison. At all.
johnss
570 posts
 
have not tried the JJ KT88s or svetlanas, so can't offer any opinion on them. But have tried dozens each of  the electro harmonix KT88 and 6550, the Mullard KT88, and Tungsol 6550 all from Russia. All are pretty reliable, have some sonic differences, Mullards are a bit warmer sounding, EH KT88 a bit more open, etc. The Tungsol re-issue 6550s sound pretty close to the original US made Tungols.

The Shuguang factory has done their homework on plate and cathode construction materials and now understands how these affect the sound of the valve. Shuguang used to make the PSVANE tubes, but now PSVANE has their own factory so is making their own valves.

If you like the sound of the GL KT88s, you may want to try the PSVANE gray glass KT88s, more open, and detailed than the GLs, but will not last as long.

Should also state my amps are not stock. All have Jensen copper foil caps installed in the coupling caps and power supply locations, which also will affect the sonic attributes of the TUT (tubes under test).



mozartfan OP
2,143 posts
 
Mullards are a bit warmer sounding

^^^^^^^^^^^^^^

Thats how me and  1 other  audiophile(quote: *I just didn't care for the GL's*, end quote) found the GL 88's. 
The GL are very popular, but just found the Svets a  superior tube.
have not tried the EH 6550;s.. I just might, ,,sometime after i get all my upgrades paid off/paypal debt.

This way I'll keep either the EH6550s or the Svets 6550.

More to discover