Shootout of Nos 6sn7 tubes

[thomask]

Don't sleep on the Brimar CV1988 Black Glass. Since you're already at 100, no need to stop there, and if you want spooky real voices, they're the one.

You shall try 6n8s tube made in 53.

https://www.amazon.com/Worlds-Greatest-Audiophile-Vocal-Recordings/dp/B000HIVOFU
I am listening to above CD through 6n8s.

Spanish Harlem
by Rebecca Pidgeon

Isn't She Lovely
by Livingston Taylor
4:30

Fever
by Valerie Joyce.


This tube is real deal with nice air and sparkle but also with full bass better than Kenrad vt231.

I ordered National Union Black grass to find out whether it sounds same as TS bgrp at 120$ total cost to me.

 

[adamaley]

National Union Black Glass is decent but not on par with the top rated tubes. I have a pair and like what it does, but it's pretty colored and accentuates the mid range - this might be great in systems that need it. It also lacks transparency.

I suggested the Brimar since you have a lot of 6SN7s and so many datapoints compared to others. Also, based on your music choices, which tend to involve vocals, the Brimar might be a keeper.

For me, transparency is key. If a tube takes that away, I tend to only use it for a flavor change every now and then. I have tubes in all my other components so it's easy to regain the areas that the TSBGRPs fall short.

I still looked into getting the Melz but I couldn't confirm the accuracy of some of the descriptions on eBay. I'd prefer to be patient to get the real deal. There were too many tubes having the same description but at extremely varying pricepoints.

 

[DaveC]

So far my overall favorite is 6n8s made in 1953.

Interesting... as I mentioned earlier I have known a few folks who have tried them all agree with this.

From my testing, I have found there are A LOT of excellent 6SN7 types that are not "hyped" as much as the 1578, TSRP, Sylvania Bad Boys, etc. and cost much, much less so personally I will leave them to those who can more easily afford them.

My preamp has a 6/12V switch so I can use 12SN7 too, that opens up even more possibilities!

 

[DaveC]

I still looked into getting the Melz but I couldn't confirm the accuracy of some of the descriptions on eBay. I'd prefer to be patient to get the real deal. There were too many tubes having the same description but at extremely varying pricepoints.

I've ordered a few times from the seller Thomas linked to in a previous post and have had good luck. I couple tubes have been damaged in shipping but may be able to be recovered, the tubes had internals shift slightly to one side, I kinda wonder if I can apply equal but opposite forces and then resolder the pins But OTOH I don't order the high-$ 1578s so I'm not worried about it too much. I got a big box full of 6N9S for very little $ about 5 years ago and all made the trip no problem.

 

[thomask]

National Union Black Glass is decent but not on par with the top rated tubes. I have a pair and like what it does, but it's pretty colored and accentuates the mid range - this might be great in systems that need it. It also lacks transparency.

I suggested the Brimar since you have a lot of 6SN7s and so many datapoints compared to others. Also, based on your music choices, which tend to involve vocals, the Brimar might be a keeper.

For me, transparency is key. If a tube takes that away, I tend to only use it for a flavor change every now and then. I have tubes in all my other components so it's easy to regain the areas that the TSBGRPs fall short.

I still looked into getting the Melz but I couldn't confirm the accuracy of some of the descriptions on eBay. I'd prefer to be patient to get the real deal. There were too many tubes having the same description but at extremely varying pricepoints.

If I want to play spooky vocal, I will insert either Syl vt231 or TS bgrp into Lm508.

I do not need another tube without bass slam.



I am playing Olympic Panfare.

6n8s give both sparkle and air on the top and also full bass slam out of it.

It sounds gorgeous through 6n8s made in 53.

 

[thomask]

I've ordered a few times from the seller Thomas linked to in a previous post and have had good luck. I couple tubes have been damaged in shipping but may be able to be recovered, the tubes had internals shift slightly to one side, I kinda wonder if I can apply equal but opposite forces and then resolder the pins But OTOH I don't order the high-$ 1578s so I'm not worried about it too much. I got a big box full of 6N9S for very little $ about 5 years ago and all made the trip no problem.

Some people claimed to have had cured the problem with re soldering pins.

They said most Russian tubes have problem with noise.

https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/page-120#post-15647922

I hope that you find method re soldering pins through above thread.

 

[adamaley]

If I want to play spooky vocal, I will insert either Syl vt231 or TS bgrp into Lm508.

I do not need another tube without bass slam.

View attachment 66057

I am playing Olympic Panfare.

6n8s give both sparkle and air on the top and also full bass slam out of it.

It sounds gorgeous through 6n8s made in 53.

If you think the vocals with the TSBGRP are spooky, then you'll really actually be spooked by the Brimars.

Anyway, thanks for your comparisons.

 

[thomask]

If you think the vocals with the TSBGRP are spooky, then you'll really actually be spooked by the Brimars.

Anyway, thanks for your comparisons.

Thanks for your recommendation.

But after going through lot of tubes, I want to choose tube with both air on the top and bass slam.

Although I use socket saver, it is still not a good idea to change tubes so often.

National Union tube could be another miss or small hit ( you never know until you receive it, I have three pair of Raytheon vt231, all of them sound different from each other).

 

[thomask]

I've ordered a few times from the seller Thomas linked to in a previous post and have had good luck. I couple tubes have been damaged in shipping but may be able to be recovered, the tubes had internals shift slightly to one side, I kinda wonder if I can apply equal but opposite forces and then resolder the pins But OTOH I don't order the high-$ 1578s so I'm not worried about it too much. I got a big box full of 6N9S for very little $ about 5 years ago and all made the trip no problem.

After several hours of listening to 6n9s, I feel this is one of the serious contender with deep bass, wide and deep soundstage, nice details.

Most Russian tubes appears to be bargain, the only issue is noise out of some tube.

 

[DaveC]

After several hours of listening to 6n9s, I feel this is one of the serious contender with deep bass, wide and deep soundstage, nice details.

Most Russian tubes appears to be bargain, the only issue is noise out of some tube.

Yup, I have some nice 6SL7 as well and the Soviet metal base 6N9S is certainly one of the best, and also inexpensive!

IDK if the Ukrainians saw this thread but there are some sales on ebay right now. I just ordered 6 of the older metal base 6N8S for $75 shipped, including expedited 6-9 day delivery that will hopefully be a little more gentle.

 

[thomask]

Yup, I have some nice 6SL7 as well and the Soviet metal base 6N9S is certainly one of the best, and also inexpensive!

IDK if the Ukrainians saw this thread but there are some sales on ebay right now. I just ordered 6 of the older metal base 6N8S for $75 shipped, including expedited 6-9 day delivery that will hopefully be a little more gentle.

I also ordered 4 more pairs of 6n8s metal base made in 50;s.

I would like to get 6n9s tube with 1579 logo on it at Ebay but no success so far.

 

[Brf]

You need to be careful purchasing 1578 tubes as many NOS sold are actually rejects that did not pass quality control. Some tube dealers will go as far as re-inking the quality control OTK stamp on the metal base. Remember, back in the Cold War days nothing was thrown out. Also, it is reported that 70’s production 1578 tubes are the best due to the fact they were destined for use in the MIG25 fighter jet program which debuted in 1970 and later phased out in 1980.

 

[thomask]

You need to be careful purchasing 1578 tubes as many NOS sold are actually rejects that did not pass quality control. Some tube dealers will go as far as re-inking the quality control OTK stamp on the metal base. Remember, back in the Cold War days nothing was thrown out. Also, it is reported that 70’s production 1578 tubes are the best due to the fact they were destined for use in the MIG25 fighter jet program which debuted in 1970 and later phased out in 1980.

Unfortunately, I can not find 1578 made in 70's at Ebay only those made in 80 and 60's.

But 1578 made in 1980 sounds fine to me.

 

[DaveC]

You need to be careful purchasing 1578 tubes as many NOS sold are actually rejects that did not pass quality control. Some tube dealers will go as far as re-inking the quality control OTK stamp on the metal base. Remember, back in the Cold War days nothing was thrown out. Also, it is reported that 70’s production 1578 tubes are the best due to the fact they were destined for use in the MIG25 fighter jet program which debuted in 1970 and later phased out in 1980.

I was thinking the holes must have been added to make the internals lighter and less likely to shift inside the envelope when used in a MiG.

AFAIK 1578 were the best testing tubes and otherwise identical to regular hole-plate tubes, but I have heard of fake 1578 logos being added too. Another reason to stick with the earlier production tubes.

 

[Lowrider75]

I was thinking the holes must have been added to make the internals lighter and less likely to shift inside the envelope when used in a MiG.

AFAIK 1578 were the best testing tubes and otherwise identical to regular hole-plate tubes, but I have heard of fake 1578 logos being added too. Another reason to stick with the earlier production tubes.

Thomas has mentioned the 1950's 6N8S tubes with Melz logo, OTK stamp, without 1578 label.
Are these an early generation tube which became the 1578 with 5 hole plates?

 

[DaveC]

Thomas has mentioned the 1950's 6N8S tubes with Melz logo, OTK stamp, without 1578 label.
Are these an early generation tube which became the 1578 with 5 hole plates?

Yes, but there are also hole plate tubes that are not 1578s. I believe 1578 was a special designation for high testing tubes.

 

[Lowrider75]

Yes, but there are also hole plate tubes that are not 1578s. I believe 1578 was a special designation for high testing tubes.

Thanks Dave, good to know. they must fetch a pretty penny if there are any available.

 

[thomask]

Third Shootout



1. National Union Black glass.



It was heard that National union did not make tube themselves but rebranded other tubes.



NU bg looks similar to either Kenrad bg or Tungsol bg.



its sounds similar to KR bg but with slightly less slam but slightly more treble extension.



i paid 120$ for this tube, It is not excellent value but worth its price overall.





2. Russian 6n8s metal base Melz made in 53



Most people talk about 1578 Melz.



But this one sounds nice with excellent bass, nice details, wide and deep soundstage.



Overall this give best performance for the cost (65$ per pair compared with 250$ per pair of 1578).



1578 sounds slightly more refined and dynamic while 6n8s made in 53 give slightly more detailed.



I had ordered four more pairs.





3. Amperex GTB



I had enjoyed Amperex 12Au7 tubes with neutral and round midrange.



Amperex may have house sound.



This Amperex gtb tube also sound round and refined midrange similar to RCA gray bottle.



It is a nice tube with Jazz.





4. CBS hytron gtb



This one sound lively with decent details and dynamics.



But compared with excellent vt231’s this tube is one notch below in details and refinement.



I would rather buy vt231’s or Russian tubes than this.





5. RCA clear bottle made in 56



I paid only 22$ for pair of this.



But it was very good value for the cost.



Sometimes you can get a hit from Ebay dealer.



It sounds similar to RCA gray bottle but with more transparency.



6. Russian 6n8s black base made in 78



I paid 46$ for quad.



But it was excellent with nice bass, details, dynamics, wide and deep soundstage.



It lacks refinement compared with 1578.



I like this tube overall.





Now I had gone through 16 different tubes.



My conclusion is all the Russian tubes give excellent bass, dynamics, wide and deep soundstage.



The best tube to me is 1578 Melz made in 1980 with explosive dynamics, widest and deepest soundstage,clean details.



TS bgrp has excellent transparency, details and speed but falls short of 1578 in dynamics and soundstage widtth.



TS bgrp sounds close to Sylvania vt 231 but more than three times of price.







My favorite is 1578 Melz, 6n8s metal base, Sylvania vt231, Kenrad vt 231, Raytheon Vt231.



RCA vt231 is also good with round and rush sound.



Pair of 6n8s metal base made in 50’s can be had under 100$ from Ebay, thus they are best value.








DetailsTransparenSpeedTonalityTreble ExTreble ClMi DynMac DynS. DepthS. widthNet costTotal Sc
TS bgrp9.59.51099.510989.5957593
RCA vt231998.59.59.598.598.5108990.5
KR vt231999108.59910998391.5
RT vt231999998.599.5996590
Syl vt10109.5810109.57.59910092.5
Bad boy87.58.597.58.58.598.5921584
15788.58.59989.59.510.51010.525094
S 181z88.5898.598.5898.512085
RCA gr87.5897.588.59.591010584.5
Syl Tall8.588.58888988.510882.5
Syl Wgt999998.5988.58.54587.5
Ts tall9998.5998.58.58.58.55487.5
Amperex8.588.59.58.598.59997688
Rca56999998.58.58892287
Cbshy989.58.5988.598.58.56586.5
6n8s(78)8.598.598.58.59999.52388.5
6n8s(53)99999.5991099.56592
NU bg9999.59998.58.5912089.5

https://www.head-fi.org/threads/shootout-of-nos-6sn7-tubes.932083/page-2

 

[asindc]

Thanks again for taking the time to report on your findings. Much appreciated.

 

[jazdoc]

Trying a set of 1943 smoked glass RCA 6SN7GT in my amp. Definitely more propulsive than metal base Sylvanias and perhaps even better bass than Ken-Rads but definitely not as sweet in the upper registers. Not strident, but not my taste. Have a set of RCA smoked glass VT-231's to compare...