[mresseguie]

I've been given an introduction to a gentleman in Taiwan who seems to be quite the authority on tube gear. He builds amps and preamps for anyone with the coin to order them (not cheap). He sells NOS tubes and potentially has a very large collection of them. I'll learn more soon. He's got a pair of Altec A5 speakers in his living room. I've been invited over to listen to them. 

Anyway, my newb question concerns NOS 6SN7 tubes (RCA, GE, Raytheon, and Kenrad) and how they compare to new 6SN7 tubes from PSVANE and Shuguang. My only experience is with new tubes from Shuguang and PSVANE 'coke bottle' tubes. The NOS tubes are much smaller. Are the NOS tubes likely to have superior sound characteristics to the new stuff?

I'm awaiting the guy's response to a question I posed to him, but I'm pretty certain I'm about to buy a pair of 1940s RCA 6SN7 tubes and a pair of GE 6SN7 tubes (date unknown). I'm buying these because one of my PSVANE tubes is becoming microphonic.

Educate me, please.

Michael

[borism]

Hi Michael,

No authority here but can talk about my experience with some 6SN7 tubes in an Atma-Sphere MP-3 preamplifier. I've tried Psvane (black bottle, CV-181-T, older generation), Ken-Rad (black bottle, VT-231) and Brimar (CV-1988). I found the Psvane to be more soft, polite and not as clear sounding. The Brimar spent the most time in the preamp followed by the Ken-Rad. They seemed more natural, present and to my liking.

Good luck!

Boris

[Tyson]

NOS Tung Sol from the 60's or earlier are the best, IME.  I also like KenRad and old RCAs.  GE's and Sylvanias are OK but not as good as these other tubes.  Ah, and Westinghouse in the tall bottles is very good too. 

But I'll tell you a secret if you promise not to tell anyone else.  Pick up some 7N7 tubes and use them with a 7N7-to-6SN7 adapter.  Some of the best octal tubes around.  They are a drop in replacement for the 6SN7 and are cheaper, too.

[RPM123]

Although I have not tried the tubes you mentioned, I am a big fan of Sophia Electric tubes...the EL34's and the 274B tubes in particular. They also make 6SN7 tubes.

https://sophiaelectric.com/collections/input-driver-tubes/products/pages-se-new-6sn7?variant=18947540484165

That being said, the Russian Melz 1578 metal based tubes are rated by many audiophiles as the "best" sounding. The good ones are scarce nowadays and very expensive. You have to do a bit of research to identify the better ones. Good luck.

[FullRangeMan]

$179.99 ouch.

In my limited experience NOS tubes til 1960s from the big US manufacturers as RCA, GE, Raytheon etc are desirable. They were made to last or at last to military use in the cold war.

I always avoid commercial tubes in favor to US and Russian military tubes.

[mresseguie]

Thanks, guys. 

Some (many? all??) of the RCA tubes were once US Navy tubes. I don't know about the remainder. The US military had a large presence in Taiwan before and during the Vietnam war. I keep getting the idea that there must have been huge stockpiles of tubes left here at some point, and certain individuals have impressive collections. I'm not a member of any of the 'inner circles' of high powered audiophiles here, so I haven't actually seen rooms filled with tubes, but I get the impression that they exist.

The two pairs will cost me approximately $200 total, so I'm willing to try them out. I do need new tubes, so I can use them. They just aren't as pretty to behold as the coke bottle tubes, but I can live with that as long as I get my sweet tube music.

[FullRangeMan]

In the days of Fi magazine Andy at VTS bought 10 million tubes from the US army.

[rotarius]

The 40s RCa grey glass are rounded and sweet.  Could be too sweet in the wrong system.  I say rounded because they are not the last word in Hf and Lf extension.  I have too many 6sn7s to count and sold off a lot as well so I could tell you the ones you would want if you tell me what is missing with your current tubes.  I do not own any of the fancy Chinese ones though just old US and Russian military ones.
PS: the GE 6sn7GTA and GTB are decent but not great.  Evenly balanced but not as refined as some of the others.  Best bang for the buck are the sylvania GTA chrome domes with a lot of flashing.  The later GTB ones are not as nice.  Btw, the 7n7 were all made by Sylvania and branded RCA, GE etc.  They have the same plate structure as the chrome domes.

[mresseguie]

The 40s RCa grey glass are rounded and sweet.  Could be too sweet in the wrong system.  I say rounded because they are not the last word in Hf and Lf extension.  I have too many 6sn7s to count and sold off a lot as well so I could tell you the ones you would want if you tell me what is missing with your current tubes.  I do not own any of the fancy Chinese ones though just old US and Russian military ones.
PS: the GE 6sn7GTA and GTB are decent but not great.  Evenly balanced but not as refined as some of the others.  Best bang for the buck are the sylvania GTA chrome domes with a lot of flashing.  The later GTB ones are not as nice.  Btw, the 7n7 were all made by Sylvania and branded RCA, GE etc.  They have the same plate structure as the chrome domes.

Good points. I appreciate your commentary on their strengths and weaknesses.

This particular system is a mixture of tube and solid state. The preamp is my 'old' Don Sachs Model 2 6SN7. It's fed by my SW1X DAC III+ NOS tube DAC. The amplifier is an IceEdge 1200as2 Class D and my speakers are Fritz Loudspeakers LS/5-R two-way monitors. My listening room is an untreated concrete rectangle. The floor is covered by an engineered wood floor on top of <you guessed it!> more concrete. Any guesses what the ceiling is? If this system were in a carpeted room with some soft surfaces, I'd expect it to be pretty neutral with a touch of warmth with great clarity/resolution from ~43Hz to 20k Hz. However, all the reflective concrete makes this system pretty lively as the volume goes up (so it seldom gets loud). [My wife finally gave me permission to add panels to the back wall and small diffusion panels behind the speakers. It took six years for her to come round.] Acoustic instruments sound magically real. A Sax is too honky unless it's at a low very well behaved volume.

Until I get round to installing the acoustic panels, I'd welcome additional 'rounded and sweet'.

These Fritz LS/5-R speakers sound wonderful within their range, but I do miss a lot of the LF sounds that I get from my Daedalus Apollos. A couple weeks ago, I had tentatively decided to find a new home for the LS/5-Rs and replace them with a kit speaker co-developed by late Jeff Bagby and Javad Shadzi called The Helios. It's a two-way using the SB Acoustics 9.5" Satori woofer paired to a SBA Be tweeter sitting in a waveguide. However, I discovered I'm loathe to make the switch because these speakers sound just lovely with my gear. I may fix my lack of bass issue by adding a couple of Rythmik Audio FM8 dual 8" subwoofers. These would become the stands and my wife can live with their esthetics.

[borism]

Michael - the Helios is a very intriguing speaker. Did you think of building them yourself or have someone else do it? My son and I built the Fusion 8 Alchemy speakers designed by Jeff Bagby and he still uses them and loves them.

[mresseguie]

Hi, borism.

I always wondered how the Fusion Alchemy speakers sound, but never heard one. Then, after some research about them, I got distracted by other baubles.

I have no tools here, so I found a guy here who builds speaker cabinets for a very reasonable fee - $325 for two stained Baltic birch Helios cabinets. Veneer would be an up charge.

If I could get a decent price for my Fritz speakers here, I'd be willing to sell them and move forward with the Helios. However, everyone I've shown them to has said, "These are kit speakers with no brand," because Fritz doesn't brand his speakers. I can't sell these for anywhere near their true value because so many buyers are so hung up on 'brand, brand, brand'.  Hence, my almost certainly keeping them and adding subwoofers to fill out the bottom end, which is very acceptable because they are excellent sounding speakers within their range.

[FullRangeMan]

You hit the point 
This remember me a such awful expensive brand that invests heavy on marketing and merchandising tô assure they are hi endy.

[rotarius]

Let us know how the RCA tubes compare to your current ones.  I have always been curious if PSvanes are worth the money.

[strateahed]

I’ve had similar experiences as borism and rotarius, on a few points. Started out replacing stock tubes with Shuguang CV181-T’s black bottle and they were OK for a short while. They were super quiet and balanced from top to bottom. But something was missing. Like the Psvane CV181-T borism described, they were soft and a little “too refined”. In the process of filtering out all the noise, they seemed to suck out music’s emotion/soul. If that makes any sense. So started my quest.

Sold the Shuguangs and replaced them with GE 6SN7GTB’s from the late 1950’s. As rotarius said, these are very good tubes but lacking in refinement. Brent Jesse at Audio Tubes.com describes them as almost as good as RCA Red Base for a whole lot less money. A sleeper bargain.

Then I picked up a pair of Ken-Rad JAN VT-231’s. These were clearly a step up, but I found the bass just a bit exaggerated for my taste.  So after more research, I got in a pair of 1940’s RCA grey glass tubes to audition. These were the tubes selected as tops from a couple of shootouts … one “double blind” with four participants:

https://audio-head.com/double-blind-a-b-schiit-shootout-tubes/   and
http://www.dehavillandhifi.com/6sn7_vt.htm

At first I really liked the RCA grey glass a lot, and found them very sweet; again, maybe too sweet. They were really quite good in mid-range and in timbre – fairly transparent. Highs were nice, but the low-end sounded a little loose. Bass is strong but not as tight as I’d like.

So long story not as long, I traded the Ken-Rads back to original seller for a pair of Sylvania 6SN7 GT “Bad Boys” and bingo, I stopped “rolling”! To my tastes, and in my system, these tubes give me what I have been looking for. They are very balanced, transparent, great timbre, with tighter, more accurate bass.   

BTW, on the strength of a mini-review on another site, I tried some cryoed Electro-Harmonix 6SN7 new production tubes from Upscale Audio; and these have many of the same qualities as the Shuguangs, except at a much lower price. That is, the EH are very quiet, smooth, and clean sounding. Actually I think I could have easily lived with these as with the Shuguangs. Just my 2 cents.

[mresseguie]

Strateahed,

Thanks for posting your thoughts. I've begun second-guessing my decision to purchase a pair of GE 6SN7s from him. He's offered to sell me RCA, GE, Raytheon, and KenRad tubes. The RCAs are from the '40s and will cost $1500 New Taiwan Dollars (~$53.50) each, the GEs are $32.06 USD each. I'll ask him about the other two. I guess I could buy two of each if I really felt like getting serious about rolling.

One (possibly two) audiophiles who are also boutique manufacturers are tentatively coming to my place on Tuesday to listen to my system. My D Sachs Model 2, my SW1X DAC, and my Fritz LS/5-R speakers are to be found in just one home in Taiwan, so my system is quite unique here.

[rotarius]

From the choices you listed, Kenrad black glass would be my pick.  It will add some bass bloom you are lacking currently. 

[Tyson]

Relative to the cost of the rest of your system, tube rolling is cheap.  I'd buy all the variants he offers and try them all out.  It's actually a lot of fun.

[borism]

Agree

[SteveFord]

I don't think you can go wrong with Sylvania. 
They just seem to do everything right.

[RPM123]

Here you go.

https://www.usaudiomart.com/details/649691680-russian-1578-finest-6sn7-variant/

If you want the best and if I still had equipment that use 6SN7 tubes, I would jump all over this pair!

I have no affiliation whatsoever with the seller.