Shootout of Nos 6sn7 tubes

[Re-tread]

Pardon the delay... finally, I can give an update on my 6SN7 trek.

Baseline refresher: for this post, I have replaced my NOS 1950's Tungsram 6SN7GT (cited above in entry # 272) with my recently acquired 1940's Sylvania VT-231 6SN7GT (image below) in the input section of my custom Blue Circle NSC preamp.



Sonic impressions: when I initially installed the Syl VT-231, it was very "crispy" in the highs; however, over the next 2-weeks it settled-in nicely (i.e., the crispy highs mellowed just a bit), leaving the following impressions: moving from the Tungsram, the Syl VT-231 reveals more high frequency information, enabling more musical details to come forth in the upper frequencies. But that's not all: I also detect that the body in the mids may be just a tad less "thick", meaning: I think the Syl VT-231 has also reduced some (previously undetected) "over exuberance" (noise?) in the mids, and my system now presents a slightly cleaner holographic scene in my musical landscape (soundscape). In hindsight, I like the overall small (nuanced) adjustment the VT-231 has introduced (brought forth). Thus, this tube is taking my system in a positive direction that suits my preferences towards my "ideal" sound. In contrast, I feel there is no sonic downside with this move (from what I like in my system, of course). Meaning, I am truly enjoying my music more! In conclusion, I like it very much!

Thus, here is the ranking of my very limited trial population (in order of preference), so far:

1. 1940's Slyvania VT-231 6SN7 GT
2. 1950's Tungsram 6SN7 GT
3. 1950's Sylvania "grey glass" 6SN7 GT
4. 2010's Electro-Harmonix 6SN7 GT (which came stock with the preamp)

The essential 6SN7 that still peaks my interest to try is the 1940's TungSol VT-231 6SN7 GT.

That's all for now.

Re-tread

 

[JBLprofan]

Hello, just curious, I just ordered the Linlai ZX-6SN7 which are "Supposed" to be better than the E-6SN7, that there are so many positive reviews about. I am wondering is there anyone on this forum that has done a direct comparison of the two? I am currently running PSVane CV-181-TII which to me sound very good, but I want to try these new ZX tubes. Thanks for your replies!

 

[DetroitVinylRob]

Hello, just curious, I just ordered the Linlai ZX-6SN7 which are "Supposed" to be better than the E-6SN7, that there are so many positive reviews about. I am wondering is there anyone on this forum that has done a direct comparison of the two? I am currently running PSVane CV-181-TII which to me sound very good, but I want to try these new ZX tubes. Thanks for your replies!

From Linlai: “ZX-6SN7 uses its own polymer composite spraying process which can quickly adsorb escaping electrons and effectively protect the glass shell from escaping electron bombardment.Enhancing the stability of the vacuum tube and making the music background peaceful and natural.”

Apparently, this is the black band on the bottle.

I have not heard any impressions on the sonic character of this creature yet. Always curious

 

[DetroitVinylRob]

Pardon the delay... finally, I can give an update on my 6SN7 trek.

Baseline refresher: for this post, I have replaced my NOS 1950's Tungsram 6SN7GT (cited above in entry # 272) with my recently acquired 1940's Sylvania VT-231 6SN7GT (image below) in the input section of my custom Blue Circle NSC preamp.

View attachment 138465

Sonic impressions: when I initially installed the Syl VT-231, it was very "crispy" in the highs; however, over the next 2-weeks it settled-in nicely (i.e., the crispy highs mellowed just a bit), leaving the following impressions: moving from the Tungsram, the Syl VT-231 reveals more high frequency information, enabling more musical details to come forth in the upper frequencies. But that's not all: I also detect that the body in the mids may be just a tad less "thick", meaning: I think the Syl VT-231 has also reduced some (previously undetected) "over exuberance" (noise?) in the mids, and my system now presents a slightly cleaner holographic scene in my musical landscape (soundscape). In hindsight, I like the overall small (nuanced) adjustment the VT-231 has introduced (brought forth). Thus, this tube is taking my system in a positive direction that suits my preferences towards my "ideal" sound. In contrast, I feel there is no sonic downside with this move (from what I like in my system, of course). Meaning, I am truly enjoying my music more! In conclusion, I like it very much!

Thus, here is the ranking of my very limited trial population (in order of preference), so far:

1. 1940's Slyvania VT-231 6SN7 GT
2. 1950's Tungsram 6SN7 GT
3. 1950's Sylvania "grey glass" 6SN7 GT
4. 2010's Electro-Harmonix 6SN7 GT (which came stock with the preamp)

The essential 6SN7 that still peaks my interest to try is the 1940's TungSol VT-231 6SN7 GT.

That's all for now.

Re-tread

The 1940’s something Sylvania VT-231 (6SN7GT) in my gear and to my ears are an absolute favorite in this house. Especially with my OTLs. The extended upper frequencies imbue a lovely, more three dimensionally realistic soundstage, more air, out of most every recording. For me, the is huge. All smiles here.

Depending on the circuit and system balance, your mileage may vary

 

[JBLprofan]

Well my Linlai ZX-6SN7's arrived and I do have to say I am VERY impressed with the initial sound, right out of the box. Right out of the box they bested my PSVane CV181-Tii . I have about 20 hours on them so far and have not really noticed any change in the sound yet. Immediately they were MUCH more airy and open in the upper midrange and treble, that is where I have noticed the most difference. My PSVane CV181's literally took 300 hours to sound their best, so it will be interesting to see if there is any change in the ZX's. Also these are dead silent so far too in my system, but my speakers are not overly sensitive 92 db. I will keep you guys posted!

 

[Dennis Meijer]

@DetroitVinylRob

If I remember correctly, you also have an Arma-Sphere, right? The Sylvania 6SN7GT Bottom Getter (VT231) is also my favorite tube, at least for midrange and high frequencies, and my starting point in the MP-1. In my opinion, this is a very musical tube that produces wonderful detail.

In my MP-1, it combines nicely with a Melz tube with holed anodes, which provides a rich fundament and a RCA-coated version (the first version ‘44) that flavors the midrange and low frequencies.

After a year and a half of not changing anything, I'm now working on a tube upgrade in my MA-1. However, I'm keeping the Linlai E (a very good tube, in my opinion) on the left rear, and to the right of it, I now have a Melz tube with ribbed anodes. This one is more linear than the holed version and has great control, especially in the bass. The Linlai with the Melz holed gives me too much midrange and low frequency bloom. I'm now working on the tube in the middle left for the final finishing touch.

 

[Lowrider75]

The 1940’s something Sylvania VT-231 (6SN7GT) in my gear and to my ears are an absolute favorite in this house. Especially with my OTLs. The extended upper frequencies imbue a lovely, more three dimensionally realistic soundstage, more air, out of most every recording. For me, the is huge. All smiles here.

Depending on the circuit and system balance, your mileage may vary

and @Dennis Meijer...
I have an Atma-Sphere S-30 mk 3.3 and I've had the same experience with the 1940s Sylvania VT-231/6SN7GT. Lovely mids and smooth extended highs. Amazing 3D imaging, lively and musical. It does lack a deep low-end so I've paired it with Ken-Rad VT-231s in the amp's cascode configuration where both pairs provide gain.
I'm also a fan of the MELZ 1578 round hole and placed them in the driver position.

 

[Dennis Meijer]

and @Dennis Meijer...
I have an Atma-Sphere S-30 mk 3.3 and I've had the same experience with the 1940s Sylvania VT-231/6SN7GT. Lovely mids and smooth extended highs. Amazing 3D imaging, lively and musical. It does lack a deep low-end so I've paired it with Ken-Rad VT-231s in the amp's cascode configuration where both pairs provide gain.
I'm also a fan of the MELZ 1578 round hole and placed them in the driver position.

It's striking that we're thinking in the same configurations. Third in the MA-1, I'm also considering the KenRad compared to the Tung Sol Black Plates (Long Bottle). Are you sitting with your system at the front or halfway up the concert hall, figuratively speaking, of course?

 

[DetroitVinylRob]

and @Dennis Meijer...
I have an Atma-Sphere S-30 mk 3.3 and I've had the same experience with the 1940s Sylvania VT-231/6SN7GT. Lovely mids and smooth extended highs. Amazing 3D imaging, lively and musical. It does lack a deep low-end so I've paired it with Ken-Rad VT-231s in the amp's cascode configuration where both pairs provide gain.
I'm also a fan of the MELZ 1578 round hole and placed them in the driver position.

Ken-Rad VT231 with parallel or staggered plates??

 

[Dennis Meijer]

Ken-Rad VT231 with parallel or staggered plates??

The KenRad VT 231 always has staggered plates. GE acquired KenRad in 1945 and continued producing the staggered GT plates with clear glass and a foil getter (later possibly a D-getter) for several years. Around 1951/1952, a parallel version with a much cheaper construction and a D-getter was introduced. According to reports from others, this is a "cheap" shadow of the staggered plate version. So, in my case, staggered plates as well.

 

[Lowrider75]

It's striking that we're thinking in the same configurations. Third in the MA-1, I'm also considering the KenRad compared to the Tung Sol Black Plates (Long Bottle). Are you sitting with your system at the front or halfway up the concert hall, figuratively speaking, of course?

I listen mostly to classical (all types) and I'm seated mid-hall, halfway as you say. With rock recordings, who knows where the soundstage will be.

 

[Lowrider75]

The KenRad VT 231 always has staggered plates. GE acquired KenRad in 1945 and continued producing the staggered GT plates with clear glass and a foil getter (later possibly a D-getter) for several years. Around 1951/1952, a parallel version with a much cheaper construction and a D-getter was introduced. According to reports from others, this is a "cheap" shadow of the staggered plate version. So, in my case, staggered plates as well.

Quite true, Dennis. I have a great dealer who informed me of the K-R history. Awhile ago he only had one matched pair of 1945s in stock and he assured me they were real Ken Rads. I was very surprised to receive a pair of tubes in GE boxes with the GE logo on the black base. They were clear glass so it was easy to certify they were genuine; staggered plates with a rectangular mica on top.

BTW, pairing the KR with the Sylvania VT-231 added a nice bottom-end and some warmth. That's when I pulled out the MELZ to get back the Sylvania transparency.

 

[Dennis Meijer]

Quite true, Dennis. I have a great dealer who informed me of the K-R history. Awhile ago he only had one matched pair of 1945s in stock and he assured me they were real Ken Rads. I was very surprised to receive a pair of tubes in GE boxes with the GE logo on the black base. They were clear glass so it was easy to certify they were genuine; staggered plates with a rectangular mica on top.

BTW, pairing the KR with the Sylvania VT-231 added a nice bottom-end and some warmth. That's when I pulled out the MELZ to get back the Sylvania transparency.

After GE acquired the company, they produced the clear glass staggered plate version for others. That's why you find the same tube under other brand names, and of course, also labeled GE. Such a version is on its way to me and should have arrived today. It was delayed by FedEx for unknown reasons. The Sylvania VT231 is my favorite tube—so musical, detailed, engaging, and 3D. I'm going to try the KenRad instead of the Linlai as the input tube in the MA-1. The Melz ribbed will stay next to it, and I have the Sylvania V231 in the center left position for now. This combination is already fantastic; with the KenRad, I expect to move it forward a few rows. The question is whether I'll always want that, or whether I'll just insert that tube occasionally depending on my mood. We'll see.

 

[Lowrider75]

After GE acquired the company, they produced the clear glass staggered plate version for others. That's why you find the same tube under other brand names, and of course, also labeled GE. Such a version is on its way to me and should have arrived today. It was delayed by FedEx for unknown reasons. The Sylvania VT231 is my favorite tube—so musical, detailed, engaging, and 3D. I'm going to try the KenRad instead of the Linlai as the input tube in the MA-1. The Melz ribbed will stay next to it, and I have the Sylvania V231 in the center left position for now. This combination is already fantastic; with the KenRad, I expect to move it forward a few rows. The question is whether I'll always want that, or whether I'll just insert that tube occasionally depending on my mood. We'll see.

The MA-1 monos are amazing.
Can you explain the input tube configuration? The 6 tubes in the S-30 layout is very straightforward.

Here is a GE tube labeled Ken Rad. It has parallel ladder plates and a round spiked mica on top....

Pardon Our Interruption...

 

[Dennis Meijer]

The MA-1 monos are amazing.
Can you explain the input tube configuration? The 6 tubes in the S-30 layout is very straightforward.

Here is a GE tube labeled Ken Rad. It has parallel ladder plates and a round spiked mica on top....

Pardon Our Interruption...

Indeed, your link refers to the cheaper version that GE later produced in this KenRad factory. I've never heard it, but according to insiders, it's best to avoid it. As I understand it from Ralph, the MA1 Mk. III has five 6SB7s. The rear 6SN7s are part of the Voltage amplifier. They are in parallel. They drive the cathodes on the 6SN7 in the middle left. The tube beside that is the Constant Current Source. These three tubes, which largely determine the sound quality, form the Voltage amplifier as a single gain stage. The front tube is the driver. It must be a GTA or GTB. It has no gain. It drives the fourteen 6AS7G tubes. In my case, these are all Svetlana tubes.

 

[Lowrider75]

After GE acquired the company, they produced the clear glass staggered plate version for others. That's why you find the same tube under other brand names, and of course, also labeled GE. Such a version is on its way to me and should have arrived today. It was delayed by FedEx for unknown reasons. The Sylvania VT231 is my favorite tube—so musical, detailed, engaging, and 3D. I'm going to try the KenRad instead of the Linlai as the input tube in the MA-1. The Melz ribbed will stay next to it, and I have the Sylvania V231 in the center left position for now. This combination is already fantastic; with the KenRad, I expect to move it forward a few rows. The question is whether I'll always want that, or whether I'll just insert that tube occasionally depending on my mood. We'll see.

The MA-1 monos are amazing.
Can you explain the input tube configuration? The 6 tubes in the S-30 layout is very straightforward.


Here is a GE tube labeled Ken Rad. It has parallel ladder plates and a round spiked mica on top.

Indeed, your link refers to the cheaper version that GE later produced in this KenRad factory. I've never heard it, but according to insiders, it's best to avoid it. As I understand it from Ralph, the MA1 Mk. III has five 6SB7s. The rear 6SN7s are part of the Voltage amplifier. They are in parallel. They drive the cathodes on the 6SN7 in the middle left. The tube beside that is the Constant Current Source. These three tubes, which largely determine the sound quality, form the Voltage amplifier as a single gain stage. The front tube is the driver. It must be a GTA or GTB. It has no gain. It drives the fourteen 6AS7G tubes. In my case, these are all Svetlana tubes.

Thanks for the explanation.
Same concept on my dual-mono amp, 2 pair 6SN7GT up front, the plate of the first tube is used to drive the cathode of the second tube.
The amp came stock with an assortment of Chinese and Russian 6SA7 output tubes. The Chinese all died within the first year. Now I'm using all Svetlana Winged-C 6H13C's purchased from Ralph. I feel very lucky to have these tubes, durable and such a sweet sound.

 

[Paul1960]

Well my Linlai ZX-6SN7's arrived and I do have to say I am VERY impressed with the initial sound, right out of the box. Right out of the box they bested my PSVane CV181-Tii . I have about 20 hours on them so far and have not really noticed any change in the sound yet. Immediately they were MUCH more airy and open in the upper midrange and treble, that is where I have noticed the most difference. My PSVane CV181's literally took 300 hours to sound their best, so it will be interesting to see if there is any change in the ZX's. Also these are dead silent so far too in my system, but my speakers are not overly sensitive 92 db. I will keep you guys posted!

How did you end up feeling about the Linlai ZX-6SN7 tubes? I'm a big fan of their E-6SN7 tubes but I had never heard of the ZX series before this and I have no idea if they are supposed to be better or worse or just different.

 

[DetroitVinylRob]

The KenRad VT 231 always has staggered plates. GE acquired KenRad in 1945 and continued producing the staggered GT plates with clear glass and a foil getter (later possibly a D-getter) for several years. Around 1951/1952, a parallel version with a much cheaper construction and a D-getter was introduced. According to reports from others, this is a "cheap" shadow of the staggered plate version. So, in my case, staggered plates as well.

So you have me curious now to acquire a few ‘40s Ken-Rad VT231 staggered plates to see if they bring a little added bass emphasis in the mix to complement the Sylvania VT-231s upper detail and midrange clarity. As some performance although remarkably musical and revealing present a tad lean in the mid bass region. Not sure where to bring them in.

I wish this was clearly documented somewhere as my understanding is not that technically oriented. I have the MA-1 Mk. 3.3v Silver Edition. Attached is a sketch of what I recall Ralph describing to me. But can’t find the associated explanation for each position. I believe V1A needed a GTA or GTB for the higher output over a GT.

 

[JBLprofan]

I still love the Linlai ZX-6sn7 's. They sound much better than PSVane CV tubes ever did. I will say that the ZX's are the only tubes I have ever used that did not change their sound at all during the burn in process, or if they did, it was such a slow, slight change that I never noticed it. I definitely would recommend them.

 

[tima]

So you have me curious now to acquire a few ‘40s Ken-Rad VT231 staggered plates to see if they bring a little added bass emphasis in the mix

I found they did in my MA-1s. With the 40s Ken-Rads and Sylvania VT-231 you've hit on two of the nicest and most hard to find NOS 6SN7s. Good luck in your search.