[Skylab]

Quote:

Originally Posted by KingStyles /img/forum/go_quote.gif I have a tungsol black oval plate on the way for my driver tube. Is there any sound difference between it and the round plates that came before and after it?

Oval plate? Are you sure you don't mean round plate with oval mica?

 

[KingStyles]

Quote:

Oval plate? Are you sure you don't mean round plate with oval mica?

Thats what I meant. Aparently they were only produced from 42-46. Before and after use the round mica.

 

[rosgr63]

Quote:

Originally Posted by markmaxx /img/forum/go_quote.gif I have seen the (tung Sol) Mickey Mouse ears on e bay recently pricey though. I have never seen or heard of a Sylvania Mickey Mouse tube.

As far as I know only Tung-Sol made the Mickey Ears.
However you can find some re-branded ones, I have one branded Motorola.

 

[Skylab]

Quote:

Originally Posted by KingStyles /img/forum/go_quote.gif Thats what I meant. Aparently they were only produced from 42-46. Before and after use the round mica.

Everything I have read seems to indicate that the mica shape did not really matter w/r/t the round-plate tube - but the round-plates I have are oval-mica.

 

[rosgr63]

skylab, what's the difference between the 6sn7gt and 6sl7gt? or VT-231 and VT-229?

EDIT I just found out that "The SN has an amplification factor of 20 and a plate resistance of about 7k7, whereas the SL is 70 and 44k respectively."

 

[monsieurguzel]

the 6sl7gt is a high gain tube compared to the 6sn7gt. From what I read, I don't think you can put one or the other since there is a 2-3X gain difference

 

[rosgr63]

That's right.
I've read that "The SN has an amplification factor of 20 and a plate resistance of about 7k7, whereas the SL is 70 and 44k respectively."

 

[tourmaline]

Quote:

Originally Posted by Nicola /img/forum/go_quote.gif I dont'like Russian or Chinese tubes, but my friend use Chinese metal base say good tube. This tubes is inexpensive but the sound is poor, hard, glass sound 7N7 is the good way, two adapters on ebay and good tubes from 10$, really there is no comparison I search an 7N7 > 6SN7 adapter

There is one special russian tube that is up to the top of the 6sn7's but the prices are going up realy fast since they seem to know this a very good tube...I still think the w's are better though...or the jan/philips...They are my number 3 and i heard alot, so this russian is beating alot of common american, chinese etc. 6sn7 tubes...it really is very good...depending on your amp, it might even be first choice.

So, yes, there are some rare good russian tubes but stash is drying up quickly and prices are going up to the point of more exotic american tubes.

 

[tourmaline]

Quote:

Originally Posted by Chuke /img/forum/go_quote.gif Thanks for the great info everyone. I just picked up a Darkvoice 336i and I've been doing a lot of searching today for 6SN7's and 6AS7's...Head-Fi, eBay, web... good stuff. I think that I recall reading somewhere that the "w" designation is for low microphonics (e.g. 6SN7WGTA). Is that correct?

I happen to know that the metal base w's are very microphonic! I own the small w's and they are silent...no humm at all.

Jan designation means tighter tolerance and better build quality of the tubes since they were made for the army/navy!

The w's i got are 40's army/navy tubes and usually this also means longer lifespan then normal tubes. Up to 10.000 hours.

 

[smeggy]

sylvania short bottle brown base W military tubes here. Sooo nice

 

[tourmaline]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif sylvania short bottle brown base W military tubes here. Sooo nice

They are one of the best!

 

[monsieurguzel]

Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif I happen to know that the metal base w's are very microphonic! I own the small w's and they are silent...no humm at all. Jan designation means tighter tolerance and better build quality of the tubes since they were made for the army/navy! The w's i got are 40's army/navy tubes and usually this also means longer lifespan then normal tubes. Up to 10.000 hours.

Actually technically, they say that the JAN VT-231 is just a code designated for military tubes. If you find a civilian tube that is the exact same year / construction as an equivalent military tube, they are said to be exactly the same in sound. The neat thing about the JAN designated tubes though, is that you know they are from the 40's - early 50's since they were all from war-time period.

 

[rosgr63]

Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif There is one special russian tube that is up to the top of the 6sn7's but the prices are going up realy fast since they seem to know this a very good tube...I still think the w's are better though...or the jan/philips...They are my number 3 and i heard alot, so this russian is beating alot of common american, chinese etc. 6sn7 tubes...it really is very good...depending on your amp, it might even be first choice. So, yes, there are some rare good russian tubes but stash is drying up quickly and prices are going up to the point of more exotic american tubes.

1578 = 6SN7 = 6N8S Metal base HOLE PLATES are the bees knees!

The ones with the holes in the side of the plates are the ones to go for.

 

[tourmaline]

Quote:

Originally Posted by monsieurguzel /img/forum/go_quote.gif Actually technically, they say that the JAN VT-231 is just a code designated for military tubes. If you find a civilian tube that is the exact same year / construction as an equivalent military tube, they are said to be exactly the same in sound. The neat thing about the JAN designated tubes though, is that you know they are from the 40's - early 50's since they were all from war-time period.

No, it has been reported that tubes with the jan designation indeed have longer lifespan and thicker materials inside. This was the case especially for navy tubes that were used in airoplanes that had to withstand quite some impact...these tubes are all higher quality! But i agree that the term is a bit of a contraversy...

Just like the russian, there might be 2 or 3 variants of one tube...the russian has 3 variants with different holes in the plate, rectangular, round and some other.....Real jan designated tubes never sound bad...

http://thetubestore.com/tubeinfo.html#q11
11. What does "JAN" in a tube name mean?
The JAN designation is found on many American made new old stock tubes, and stands for "Joint Army Navy". It means they were originally built for the military, often with improvements in their construction and quality control.

 

[tourmaline]

Quote:

Originally Posted by rosgr63 /img/forum/go_quote.gif 1578 = 6SN7 = 6N8S Metal base HOLE PLATES are the bees knees! The ones with the holes in the side of the plates are the ones to go for.

Yes, someone reported to me that there are at least 3 variants and the one with the whole in the plates sound best...(just like the round plates?) still, the w's are a perfect match for the russians or slightly better.

They are also getting expensive now, i still have a few but don't care too much for them in my amp, a bit on the soft side...the jan/philips and the w's are better in my amp at least. Also better as a driver tube, since i used a w or a jan/philips in front of 2 russians and it sounded much better...meaning the russians are better for output tube and not as a driver. Also confirmed by others...

But they are certainly in the top 3 of best 6sn7's.