[rosgr63]

I can confirm xcalibur's findings.
I too have found that the copper rod versions of the same tube sound smoother.
I noticed it by accident using TS 6SN7 BGRP's but since then on some other brands aswell.
 
EDIT Rob and David my hearing if anything is not that good, but I detected the diference before Xcalibur mentioned this. However some really nice tubes like the B65/QB65/QA2408, etc that have steel posts sound great.

 

[Skylab]

I will need to make a test! I have more of the copper than the steel, thank goodness

 

[rosgr63]

Good morning Rob,
It'll be very interesting to see what you find out.
 
Meantime when the ebay God's fall asleep and the addiction never stops.......
 
Note that the non military versions are shorter.
 
 

 
 

 

[Blackmore]

 Man, I wouldnt mind to have extra one of these, fantastic tubes, congrats!
 

Quote:

Good morning Rob,
It'll be very interesting to see what you find out.
 
Meantime when the ebay God's fall asleep and the addiction never stops.......
 
Note that the non military versions are shorter.
 
 

 
 

 

[rosgr63]

My Tube Mate, let's wait until the amp tests are finished.
 
We've seen too many bad tubes been sold lately, so keep  your fingers crossed for me! 

 

[Xcalibur255]

If you want to unload the single tube I would be interested as well. 

 

[Skylab]

I wonder if we could get moderator permission to openly discuss buy/sell/trade of only 6N7's in this thread

 

[9pintube]

Quote:

I wouldn't go opening tubes. Unless you enjoy Mercury poisoning.

Duh---------------------- very good advice Skylab !!!   Be safe with dead tubes, make Christmas tree declarations out of your bad tubes...... I use an old Western Electric 300B for my trees star.... Back to the 6sn7 tubes, I can't get past the sound of the RCA 5692 "Red Base" tubes, or for some more detail The Ken-Rad VT-231 Black Glass... Does anyone find the VT-231 to be a little microphonic? 

 

[Skylab]

Every Ken Rad 6SN7 I ever owned was very microphonic. I thought it was bad luck, but now I'm not so sure.

 

[tagosaku]

Quote:

I will need to make a test! I have more of the copper than the steel, thank goodness

 
 
Lucky you. I have three steel and one copper

 

[Silent One]

Quote:

I wonder if we could get moderator permission to openly discuss buy/sell/trade of only 6N7's in this thread

 

 I'll have ur back!

 

[rosgr63]

Xcalibur, have you ever had your misbehaving TS tested?
I can't understand why both are playing up.
After how many hours did the problem surface?
 
Another observation, I noticed some tubes that are used which is evident from cathode boil off marks test much stronger than others which don't have any marks at all. Any ideas why this is so?
 
I think it would be a great idea if the moderators would allow tube sales/trades within this thread.
I personally have not sold/traded a single tube yet, but I don't mind helping people to find what they are looking for, if I can that is.

 

[blairfrischx]

Quote:

Every Ken Rad 6SN7 I ever owned was very microphonic. I thought it was bad luck, but now I'm not so sure.

I also own one. It is indeed very microphonic.

 

[Blackmore]

 Is it possible that this may depends on amp?
Quote:

I also own one. It is indeed very microphonic.

 

[Xcalibur255]

Quote:

Xcalibur, have you ever had your misbehaving TS tested?
I can't understand why both are playing up.
After how many hours did the problem surface?
 
Another observation, I noticed some tubes that are used which is evident from cathode boil off marks test much stronger than others which don't have any marks at all. Any ideas why this is so?
 
I think it would be a great idea if the moderators would allow tube sales/trades within this thread.
I personally have not sold/traded a single tube yet, but I don't mind helping people to find what they are looking for, if I can that is.

Not re-tested, but they were well tested by the seller (whom I trust) when I bought them.  Actually a number of other people on the forum bought tubes from the same person around the same time and nobody seemed to have problems.  These tubes were silent and well-behaved in my old Woo amp, but at the same time I can't really point the finger at my current amp because these are the only tubes acting up out of the whole collection.  It seems to be a vibration problem, if I tap the desk hard it will throw either of the tung sols into fits.  The worse of the two will just start howling and your only choice is to turn the amp off, this one used to be fine but it too howls but quiets back down.  The big sticker is there is static in the left channel that is constant and its enough to make me want to pull it out of the amp.
 
I'm giving the tube 2 weeks to see if some hours help/hurt then I'm just going to put them back in the box and reflect on what a waste of $400 they were.
 
As for your second question, I suspect you know more about tubes than I do but I have read that tubes don't really achieve their full emission until they have been used for a couple hundred hours at least, then they stabilize and very gradually lose emission over their lifetime.  I've experienced this with my 5998 tubes.  They were real NOS tubes and sounded pretty awful at first, like they were used up and weak.  Over the course of burn-in they steadily became stronger until the sound stabilized about 150 hours in.  So maybe very new tubes are just testing weaker because they are unused sometimes.