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6SN7 Tube Addicts - Page 218

post #3256 of 4484
Quote:
Originally Posted by mikey8811 View Post

Hi Xcalibur

 

I got these Sylvania GT's last week.

 

Processed By eBay with ImageMagick, R1.1.1.M2b

 

The ones on either side are the ones you like, I believe.

 

What is the centre one? It has a full getter flashing but also a taller base. Could it be the same as the Syl 6SN7W? Alternatively, could it be the same as the tube I posted about last year (pictured below), which could possibly be the true Chrome Dome?

 

Syl2b.jpg

 

Syl2a.jpg

 

Thanks

 

Have you tried listening to them yet?

 

The one in the middle is your jackpot IMO.  What matters is the getter flash, notice how it goes so far down the glass it reaches the bottom mica plate?  Those are the ones that sound great, I think they have shown up in both the normal and short base types.  Sylvania mixed and matched on this stuff a lot.  I have a pair with different bottom micas too, one has teeth and one does not but both tubes sound identical.  The getter flash covering the whole tube is the only reliable indicator.  There is a fine line between the GT and GTA, they can be hard to tell apart.  One way to tell is that the flashing looks "cleaner" on the GTAs.  These are the tubes I avoid, they don't sound as good.  The flashing on yours looks a bit on the short side but I do still think they are GTs.  They should all have 3 hole plates, I've never seen the 2-hole plate type with the heavy top getter flash in this glass envelope length.  The 6SN7W is a top getter with pretty heavy flashing, and that one is 2-hole, but the glass is shorter and there should be a metal support rod between the plates.  Your tubes are all medium glass.

 

Whenever somebody tries this tube and tells me they thought it was ordinary I have become convinced they're not actually finding the right tube.  The real deal gives you that sort of "aha!" feeling of total transparency that very few tubes do. 

 

I have a pair that looks exactly like the ones on the ends of your photo and I think they sound great too.  What you primarily gain is more transparency trying to hunt down the rare oddballs.  All three in the photo are great tubes and worth owning.  I would try to hunt down a friend for the one in the middle if your amp uses pairs, it would probably be worth it.  But remember we all have our own tastes too.  Some people don't like the BGRP Tung Sol despite its reputation.  You have to trust what your own ears tell you is good, not mine.


Edited by Xcalibur255 - 2/25/13 at 3:45pm
post #3257 of 4484

Hi Xcalibur

 

Yes, I have tried them. I liked both the ones with the shorter base (side tubes) and the ones with the fuller getter flashing (centre tube). Both types were very close in sound. The construction of the latter ie. the middle tube appear to be very close to the older tube also with full getter flashing that I posted. I used them as a pair. I was confused by the JAN 6SN7 GT labelling and thought that it was a mislabelled JAN 6SN7 W instead because I referred to your earlier post on the Woo Audio Amp Owners thread comparing the 4 Syl GT & W types.

 

As far as the sound goes, the ones with the fuller getter flashing have more treble resolution which is extended and yet not bright and more bass although the bass is less tight than the other short base type which appeared to be faster  (I don't know if this is a result of my having also changed the rectifier tube in my preamp power supply to a Mullard 5AR4). Both have a lilting quality to the upper mids that is very attractive on female vocals. It was the bass quality that made me think the tubes were the 6SN7 W's as that seemed to be your impression in your comparison piece. Other than the fuller getter flashing, I had thought that the other identifying characteristic was the mica material which is a little chalky as opposed to being a more finished metal sheen. If the side tubes are not the same as the centre one, then where do they belong in the Syl camp? Are they more like the GTA's?

 

 

I also just scored another pair of similar looking tubes (pics below) and have yet to receive them so I do not know if they are the same. They also have a fuller getter flashing from the pics but I can't tell if they have 3 hole plates or not. If they are indeed the same, then I can try them as a quad.

 

Processed By eBay with ImageMagick, R1.1.1.M2b


Edited by mikey8811 - 2/26/13 at 2:45am
post #3258 of 4484

Well I got some RCA ladder type coin base 6SN7's, these sound pretty good.

post #3259 of 4484
Thread Starter 
Quote:
Originally Posted by Skylab View Post

Well, without knowing the tube code it's kinda tough.  Wehrmacht tubes were the WW2 German Military tubes. Tube numbering scheme I believe was totally unique to them during the period.  

 

So...what is it? 

 

Quote:
Originally Posted by Oskari View Post

I think we have a twister here. I'll keep quiet for now in case there are others who like the challenge.

 

This is a twister indeed, well spotted.

Oskari I think you know what it is.

 

6H12C Update

 

I just received the new pair and realised there are two different types:

 

 

The one I had has short bottle 5 support rods, single getter, dull plates.
The new arrivals, have longer bottle with 4 support rods, double getter and shiny plates.
post #3260 of 4484

Well, since there aren't any other takers, I suspect it's a Valvo 328A. A Western Electric type in Wehrmacht colours!

post #3261 of 4484
Thread Starter 

Very Well Done!!!!!!! beerchug.gif

 

Part of a matched pair.

 

You are too good I must admit.

 

BTW here is an older RFT 1954 vintage?

Notice the non ceramic spacers and large plates.

 

 

 

 

 

EDIT:spacers


Edited by rosgr63 - 2/26/13 at 10:52am
post #3262 of 4484
Thread Starter 

Here it is:

 

 

Processed By eBay with ImageMagick, R1.1.1.||B2||T0JKX0lEPTVjYTFhYjFlYTQ0NzI0MzAwNTA5YmM2ZGFlMTVjZjA1MGEyYmNjYzgxZDJifHxTRUxMRVJfTkFNRT1mcmF1LW9saWF8fE9SSUdJTkFMX0VCQVlfUVVBTElUWV9TQ09SRT00fHxDUkVBVElPTl9EQVRFPTEyLzI4LzEyIDQ6MDcgQU0=

post #3263 of 4484

Somewhere in my attic, I have a 1950s Admiral black and white television chock-full of those Sylvania 6SN7s (with elongated gettering). I may pull them and sell them. I could easily insert a lesser tube in that tv chassis and get the same performance.

post #3264 of 4484
Quote:
Originally Posted by Skylab View Post

Wehrmacht tubes were the WW2 German Military tubes. Tube numbering scheme I believe was totally unique to them during the period.

 

The problem was I couldn't find any matching Wehrmacht types, but they didn't use just their own types. Next I considered Poströhren, and the C3b/C3c/C3d came close but they all seemed coated. Then I somehow got the Valvo feeling and started looking for examples of Valvo C3-something-early. Suddenly the 328A popped up.

 

Quote:
Originally Posted by rosgr63 View Post

You are too good I must admit.

 

I think the word is persistent.

post #3265 of 4484

mikey, keep in mind equipment matters a lot too.  The tubes will behave differently in different circuits, in a manner of speaking my original writeup on the Sylvania tubes is only really valid if you are a WA6 user.  I've found in my OTL most of the tubes sound different, though many do retain a fundamental base quality that defines their character.

 

You've scored some great tubes, I don't think any of yours are GTAs, not the ones in your photos anyway.  I find the GTAs to be ordinary and unimpressive.  There is nothing wrong with them, and are preferable to modern production tubes for sure, but they lack finesse and feel less balanced tonally.

 

I don't think you can be sure of anything by the mica types, Sylvania mixed and matched parts too much.  But the GTAs were made on different tooling, the getter flashing is clearly different if you compare them directly.  Since you like both of the tubes in your photos I wouldn't worry about sub-defining each one and just enjoy them, or pursue which ever you like more.  FWIW though one of the defining qualities of the Sylvania tube I like best is the bass quality.  Very fast and controlled with great texture and weight.  They have a deceiving since of dynamic ease and range that other popular Sylvania tubes like the Bad Boy do not have.

 

I'm not actively collecting anymore myself, it got too expensive plus you have to stop somewhere or there really is no end to it.  Once you find a tube that makes you feel really content I would find a backup pair and then just enjoy them.  wink_face.gif


Edited by Xcalibur255 - 2/26/13 at 3:48pm
post #3266 of 4484
Thread Starter 
Quote:
Originally Posted by Oskari View Post

 

The problem was I couldn't find any matching Wehrmacht types, but they didn't use just their own types. Next I considered Poströhren, and the C3b/C3c/C3d came close but they all seemed coated. Then I somehow got the Valvo feeling and started looking for examples of Valvo C3-something-early. Suddenly the 328A popped up.

 

 

I think the word is persistent.

 

 

The word is GOOD, but you are too modest to accept.

post #3267 of 4484

Certainly way beyond me.  I could never have figured out what it was without referencing the tube code.  Never heard of the 328A. What is it compatible with?

post #3268 of 4484
Thread Starter 

Rob the 328A is the 7.5V variant of the 310A and 310B which have a 10V heater voltage.

 

Reputed to be one of the best ever audio tubes.

post #3269 of 4484

Stavros, in what amp do you use it?

post #3270 of 4484
Thread Starter 

A custom made one getting built soon.

A pair of either 310A or 310B or 328A will be the drivers.

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