6SN7 Tube Addicts - Page 212

Undeniably a terrific and underrated tube, I agree wholeheartedly. 

I bite on the RCA red base 5692 for my 336se. What a waste of Xmas money. I even upgraded my interconnects to Zu Audio missions. The upgrade only helped the RCA crawl a bit faster. Yes very flat!!! I have a KenRad I like and a sylvania I found in a 1952 tv in my basement. It's a jewel.
What's the communities opinion on the "bad boy"
I am going to try a CBS Hytron. Anything special I should be looking for before purchase.
Anyone wanna buy an RCA red base 5692?

The red base 5692 are meant to be run at lower voltages, which is why they are a long lasting tube. As far as sound, I have a number of NOS and for some reason people think they should sound good, they suck. The same can not be said of the 5691, which is a type of 6SL7. They sound very good but not so with the 5692.

 

The Sylvania 1952 shiny mica 6SN7 has pretty much everything for sound but not everyone loves them. I also have some nice 1940's Tungsol round plate and they are very nice. There are so many 6SN7's that still don't cost a lot that sound excellent. It is often just getting the operating points of the tubes at the right place to get the best sound out of a particular tube as manufactures and era when the tube was manufactured, changed some of the operating points of the tube.

Jam!!!!!! Nice to "see" you here.

 

+1!  And......weren't you just in Arizona a minute ago?! Hope your new locale is workin' out.

"So", do u want mean that the best tubes are of that era? cuz that era were the boom of vacuum tube?

Exactly!  Like the VT-231 for example.  If you run VT-231's on circuit with plate voltage designed for GTA or GTB then  your beloved tube will not last as you have expected.

Edited by amandarae - 1/31/13 at 5:06pm

 

I don't understand this.  Aren't VT-231s and GTAs/GTBs all 6SN7s?

Yes...BUT...

 

A 6SN7GT is rated for a plate voltage of 300V.  A 6SN7GTA/B is rated for 450V.  So if the circuit is designed for "universal" 6SN7 use, it needs to present a plate voltage of 300V.  In practice BTW this is what most designers do, so the scenario of burning up your 6SN7GTs is a rare one.

Yes, nice to see you also, so to speak. :^)

 

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Tubes had parameters but changes often occurred that allowed them to operate at different points but have basically the same function in the circuit, as pointed out above. The 6SN7 was a current tube whereas the 6SL7 was a voltage tube with a much higher gain. I have 27 balloon tubes made in 1929 to 1932 that operate at certain points but later 27's can operate better at a little different points, while doing the same job in the circuit. The 76 is a coke bottle shape that came after the 27 and preceded the 6SN7 as it was like one side of a 6SN7 since the 6SN7 is a dual triode. The 76 works best operated right at maximum current and voltage but won't last as long as lower points but sounds best there. It is all a balanced act and knowing your tubes.

 

I now travel with a nice calibrated TV7 just in case I come across any tubes. Got to be prepared you know. lol

Hello,

 

I did not say "burning up", I am saying it will not last as long as the GTA/GTB's.  

I'm using 6SN7's as driver tubes in my SET amplifier. The output stage of the 6SN7 is coupled with the output tube grid by a capacitor. I have been thinking of changing that capacitor for an interstage transformer, mainly due to the voltage limitation of the capacitor, which limits the power I could be drawing from my o/p tube (i.e, could I go up with the voltage, I could have 30% more power.)

I was told by a transformer manufacturer that the 6SN7 is not a good tube to use with interstage transformers, and that I would be better off with the 6BL7 due to its lower o/p resistance. I wonder if anybody here has had some experience with this, or would have an informed opinion about this...

Go over to Audio Asylum to the tube section and ask or do a search.

I have a range of 6SN7 variants I use in my customised Icon Audio HP8 Mark II.  They are an excellent source of help and advice in relationship to tubes and sell a broad range, their headphone amps are also out of this world, paired with my Schiit DAC the sound output is sumptuous.

 

http://www.iconaudio.com/audio-valves/

 

 

My current 6SN7... :-)