[larcenasb]

If a 6SN7 is rated 75/100 and the minimum rating on the tube tester is 70, what's a ballpark guess about how many hours it will last? Thanks!

 

[r one]

A new 6sn7 would give a gm emission 10 or 20% over his full genuine capacity.
At 110 or 120 % of transductance capacity you are sure that the tube is new and unused. At 60% of emission tube is simply. ..dead.

For your example at 75 /100, this tube is unbalanced and one of the two triode is dead.

 

[spacequeen7]

*

 

[larcenasb]

A new 6sn7 would give a gm emission 10 or 20% over his full genuine capacity.
At 110 or 120 % of transductance capacity you are sure that the tube is new and unused. At 60% of emission tube is simply. ..dead.

For your example at 75 /100, this tube is unbalanced and one of the two triode is dead.

But I'm listening to music through it and it sounds great! I'm just wondering how many hours it might last till it actually does die.

 

[r one]

Generally tubes manufacturer indicate that you have to change the tube when it fall down a about 60%. But it could working again for many hours but at an insuffisent level.

 

[larcenasb]

Generally tubes manufacturer indicate that you have to change the tube when it fall down a about 60%. But it could working again for many hours but at an insuffisent level.

Thanks for your replies, this tube I'm talking about is a Tung-Sol 6SN7GT round plate. I love the body and smoothness of the midrange -- sounds so effortless. I hope it lasts! Cheers!

 

[r one]

I understand. It's my favorite too

 

[abvolt]

  Thanks for your replies, this tube I'm talking about is a Tung-Sol 6SN7GT round plate. I love the body and smoothness of the midrange -- sounds so effortless. I hope it lasts! Cheers!

I'd agree that's a great sounding tube..Enjoy

 

[leftside]

Anyone tried the new Psvane 6SN7 CV181 TII's?
http://psvanetube.com/wordpress/store/products/cv181-tii-pair/

 

[Mechans1]

  Here is more anecdotal evidence that some tubes even when dead tubes can affect your system in a positive way.      I have a  pair of Marconi-phone (made in Great Britain) B309 which are equivalent to a 12AT7.  These tubes read dead on my Hicock 6000A.  I tried them anyway and they sounded truly great really superb.  I rolled anything that was pinout compatible with small tube Integrated amp, a Consonance M100+.        

 

[larcenasb]

    Here is more anecdotal evidence that some tubes even when dead tubes can affect your system in a positive way.      I have a  pair of Marconi-phone (made in Great Britain) B309 which are equivalent to a 12AT7.  These tubes read dead on my Hicock 6000A.  I tried them anyway and they sounded truly great really superb.  I rolled anything that was pinout compatible with small tube Integrated amp, a Consonance M100+.        

Great to hear! Using my near-dead tube makes me appreciate every second of every song so much more -- I don't waste time listening to whatever! This is the bushido code applied to hi-fi, haha.

 

[SonicTrance]

    Here is more anecdotal evidence that some tubes even when dead tubes can affect your system in a positive way.      I have a  pair of Marconi-phone (made in Great Britain) B309 which are equivalent to a 12AT7.  These tubes read dead on my Hicock 6000A.  I tried them anyway and they sounded truly great really superb.  I rolled anything that was pinout compatible with small tube Integrated amp, a Consonance M100+.        

It depends on the operating point. Say you test a 6SN7 in a tester @ 250V on the plate and it reads low on gm. The you plug the same tube into your amp which lets say gives it 100V on the plate, then the tube will have higher gm. Lower plate voltage gives the tube higher transconductance.

 

[r one]

Anyone can explain me a date code marked on a VT 231 Rp Tung-Sol : 50-645-A. Is it a year indication ?

 

[gibosi]

  Anyone can explain me a date code marked on a VT 231 Rp Tung-Sol : 50-645-A. Is it a year indication ?

 
How about a picture, so we can see....
 
But just guessing... have no idea about 50 or A.... However, 645 appears to conform to an American date-code format commonly used at that time, 1946, week 45.

 

[r one]

i  thought the same thing but this is for the most older version of Ts Rp which have a circum mica instead of an oval.  in my mind this model was replaced by the oval mica version during the 1940's.