6SN7 Tube Addicts - Page 202

Just bought some Kenrad black glass VT-231. They sound fine, but if you pause the CD or between discs, when you tap gently on the base or glass, you can hear the faint tapping on the speakers. One tube is slightly louder than the other. Is this normal as I heard these tubes tend to be microphonic? No howling or squealing or hums or static noises though. A pair of clean NOS like this is hard to find, so I'm inclined to keep them if this is normal.

This is pretty normal for Ken-Rads.  If yours are quiet when they are not picking up vibration then you did pretty good.

Where are you finding these?

I don't know, Stavors.  You seem to win the lottery all too often...

Quote:

Originally Posted by rosgr63 

From what I remember TS come in three plate types Flat ...

I find the TS flat-plate 6F8G a bit on the flat side. The TS 5998 is very dynamic, even too dynamic at times. It is perhaps not too surprising, in hindsight, that they work very beautifully together.

Just an observation, to my ears, in my amp, as usual.

Can someone identify the manufacturer of this?

http://www.ebay.com/itm/2-pcs-Wards-Super-Airline-6F8G-dual-triode-tubes-NOS-/251195828361?pt=Vintage_Electronics_R2&hash=item3a7c702889

Quote:

Originally Posted by Xcalibur255 

Indeed.  They were made by human hands afterall.  There were lots of possibilities for variation from sample to sample, both from the people assembling them and the equipment on the particular line it was coming off of.  Especially the ones from the 40's and early 50's before some of the major processes were automated by machines.

Xcalibur, The Grey Glass RCA & NU Black Glass combination came close to the Grey Glass RCA & 1950's Sylvania Chrome Dome GT of the construction you like. The latter combination (had a quad of RCA's in the phase splitter positions and the Sylvania's in the gain buffers) was better on vocals and jazz - female vocals were more lilting and there was more air albeit smooth in the treble. Bass though was slightly soft.

With the NU's, pop and rock sounded better, the sound was fuller and more punchy.

Unfortunately, the Sylvania's are hard to come by. I have been looking for them with not much success. The NU's pop up every now and then.

By the way, how do CBS Hytron's (black base, white label) or CBS (black base red label) compare to these tubes?

Quote:

Originally Posted by rosgr63 

I tried the Sylvania Xcalibur mentioned in my Glenn OTL amp and found it ordinary.

For that system I prefer the FIVRE 6SN7.

 

The Hytron comes in various types, early(Hytron logo) and late(CBS-Hytron, logo) versions, two and three hole plates.

Which are the ones you are referring to? 

These ones. 2 hole plate. Are they different?

How do they sound vis-a-vis the 3 hole plate?

mikey, they should be the same.  If the type logo is stamped on the top with a circle around it that is the easiest way to spot Hytron T-plates.  Great tubes, they have an amazing midrange and are full bodied.  If you like the NU sound this is an improvement upon it in my personal opinion whilst having fallen from the same tree so to speak.  I've tried to like the NUs, they are quite dynamic and sometimes there is real magic in the mids but half the time they sound wrong tonally and are just too soft at both ends of the spectrum.

rosgr, I'm starting to wonder if maybe it is just me after all with these Sylvanias.  There is no tube I would take over it except for the round plate tung sol but whenever anybody else tries them they find it to be average.  Maybe mine are unique somehow?  All the ones I have came from the same batch code after all.  I own other Sylvania t-plates, bad boys, the Ws and none of them compare to this tube if you ask me.  They're just so amazingly transparent to my ears.