[Ranger Ron]

Just an enquiring mind. Were these National Union Grey Glass tubes the forerunner to the tubes above? And would the internals be the same?

Yes they are earlier than the black glass. The structure is slightly different from what I can see. They have U shaped shields on top of the mica where the black do not. The Sonics are different as well. Nice looking pair you have there.

 

[triod750]

Change of subject. I have a pair of Sylvania short bottle brown base 6SN7 WGT coded L2B on top of the glass. I have never liked them much. To me they sound somehow 'artificial'. The other day I installed them as output tubes while 'burning in' a pair of Sylvania 6L5G after trying different output tubes before them. To my surprise they perform pretty good in this combination. A bit rolled off up top but the 'artificiality' was gone and the tone was better than with, for instance, Melz 6N12S, GEC CV4079 or Brimar bottom square getter 6SN7GT.
Never rule out a tube...

 

[UntilThen]

Is this what you have? I got it off a submarine.

 

[g0ldl10n]

This is why I am in the redemption mode now, have been exploring tubes no more than USD25 a piece....
Have many great results with tubes at about USD10 NOS a piece, even GEC L63 straight glass is too evil for me to try....

I just scored some extremely nice mint conditioned NOS/NIB tubes for 68 cents a piece (this includes shipping) that have amazing results, lol. Granted, it took me a whole lot of time and money to find these types of diamonds in the rough (with your help!), but think it has definitely paid off since I have found enough of these at low enough prices to probably have a lifetime supply of each type of my favorite tubes in mint condition.

 

[TLO]

I just scored some extremely nice mint conditioned NOS/NIB tubes for 68 cents a piece (this includes shipping) that have amazing results, lol. Granted, it took me a whole lot of time and money to find these types of diamonds in the rough (with your help!), but think it has definitely paid off since I have found enough of these at low enough prices to probably have a lifetime supply of each type of my favorite tubes in mint condition.

Congrats!!! Full of unimaginable satisfaction and excitement...lol

 

[ostewart]

I have 3 pairs of NU, used to have 5 pairs. Have seen many different combinations of mica in different year, top and bottom spiked rectangluar, top rectangluar with spacer and bottom spiked rectangluar, top spiked rectangluar and bottom round but they all have bottom getter flash. That one you see at the top is not getter flash but emission mark.

The one with oval mica and emission marks on the top sounds awful in my Xduoo TA-26 with Mullard 6080... kind of thin and not very nice tonality, sounding quite artificial.

The one with the clear top and round mica is a bit better, but still not to my liking - I got them as a lucky dip pair for £37.50 so can't complain as such, but they are not very good IMO.

The Hitachi 6SN7GTB on the other hand sounds lovely, nice full low end with great treble that's well extended, really nice.

Once these arrive, it will be interesting to hear them:

So far though, my Rogers rebranded Sylvania 6SN7GT - black T-plates, round micas, 4 umbrella spokes, chrome top with D getter and the new Hitachi Japan 6SN7GTB are my favourites.

 

[TLO]

The one with oval mica and emission marks on the top sounds awful in my Xduoo TA-26 with Mullard 6080... kind of thin and not very nice tonality, sounding quite artificial.

The one with the clear top and round mica is a bit better, but still not to my liking - I got them as a lucky dip pair for £37.50 so can't complain as such, but they are not very good IMO.

The Hitachi 6SN7GTB on the other hand sounds lovely, nice full low end with great treble that's well extended, really nice.

Once these arrive, it will be interesting to hear them:

So far though, my Rogers rebranded Sylvania 6SN7GT - black T-plates, round micas, 4 umbrella spokes, chrome top with D getter and the new Hitachi Japan 6SN7GTB are my favourites.

Not really surprised...TBH, I bet not many will like NU 6SN7 (blk glass) as it is very "neutral" or even slightly dark but not as dark as RCA 6SN7, RCA has more air....could say NU has lesser coloration compared to other 6SN7s, some will find it sounds boring though. On the contrary, I didnt find NU 6SN7 sounds thin, perhaps due to the circuit / amp design or tubes matching....this is one of the best setup I have ever heard....

PSVANE WE300B
MULLARD CV593
NU 6SN7
PHILIPS ECC40

It also plays very well on another amp, Line Magnetic LM-508, with this setup...

PSVANE WE300B
PSVANE ACME 805
MULLARD ECC35
NU 6SN7

 

[triod750]

Is this what you have? I got it off a submarine.

No, my pair has getter flash as low as 6SN7W metal base has. They also have 'umbrella spokes' holding top mica off the glass sides.

 

[g0ldl10n]

Congrats!!! Full of unimaginable satisfaction and excitement...lol

For sure! These definitely met our goal of finding mint condition NIB tubes with great SQ at $1/tube or less. Hopefully more to come!

 

[g0ldl10n]

Not really surprised...TBH, I bet not many will like NU 6SN7 (blk glass) as it is very "neutral" or even slightly dark but not as dark as RCA 6SN7, RCA has more air....could say NU has lesser coloration compared to other 6SN7s, some will find it sounds boring though. On the contrary, I didnt find NU 6SN7 sounds thin, perhaps due to the circuit / amp design or tubes matching....this is one of the best setup I have ever heard....

PSVANE WE300B
MULLARD CV593
NU 6SN7
PHILIPS ECC40


It also plays very well on another amp, Line Magnetic LM-508, with this setup...

PSVANE WE300B
PSVANE ACME 805
MULLARD ECC35
NU 6SN7

Damn, that is a lovely looking setup.

And @ostewart, do you have a different OTL amp that uses the same input and output as your TA-26? Only asking because I did not have a good experience with that specific amp, so if you do, I would definitely try running those NU 6SN7 tubes in a different amp to see if you get the same results. The first one I got actually sounded quite strange/wierd/distorted compred to my Darkvoice 336se that I thought it was defective, so I had returned it for a replacement unit, but that one too sounded exactly the same. Maybe it's just me or my preference, but I found it does not play as well to my taste in comparison to my other two OTL amps using same tubes, DV and Eufonika H5M.

 

[ostewart]

Damn, that is a lovely looking setup.

And @ostewart, do you have a different OTL amp that uses the same input and output as your TA-26? Only asking because I did not have a good experience with that specific amp, so if you do, I would definitely try running those NU 6SN7 tubes in a different amp to see if you get the same results. The first one I got actually sounded quite strange/wierd/distorted compred to my Darkvoice 336se that I thought it was defective, so I had returned it for a replacement unit, but that one too sounded exactly the same. Maybe it's just me or my preference, but I found it does not play as well to my taste in comparison to my other two OTL amps using same tubes, DV and Eufonika H5M.

My TA-26 works really well, no distortion and excellent sound with the right tubes

I'll hang on to the NU tubes for future use maybe.

 

[TLO]

For sure! These definitely met our goal of finding mint condition NIB tubes with great SQ at $1/tube or less. Hopefully more to come!

I am still looking for that $1 NIB tube...lol
My best up-to-date record is at $5 shipped...unused true NOS.

 

[UntilThen]

I don't roll tubes now. I roll Grados.

 

[LobalWarming]

I don't roll tubes now. I roll Grados.

Probably cheaper. Just harder on your ears.

 

[TLO]

I don't roll tubes now. I roll Grados.

For a moment, I thought it is one of those funny names...LOL