[Freo-1]

 Decided to conduct some tube rolling with the Modwright Oppo BDP 95 to see if improved overall performance could be achieved.  Here is a summary of the results.

1. After trying various 6SN7 tubes from varying vintages and makes, (at least a half dozen makes/types), the best overall performance was obtained with Sylvania MIL-SPEC chrome tops from the 50’s.  They had more clarity, presence, and depth, along with a lower noise floor compared to other 6SN7’s I tried.
2. From there, tried 5692 tubes in place of 6SN7’s.  All of the 5692’s were a step up from any of the 6SN7’s.  Noise, clarity, dynamics, presence, you name it, the 5692 sounds and performs better, no question in my system.  All the 5692’s sounded pretty similar (RCA, Sylvania, CBS).  I think the differences are system dependant.
3. Once the driver tubes were settled upon, rolled in different rectifier tubes (5AR4, 5V4G, 5U4G) to see what differences there would be.  I initially thought that there would not be much difference, but that was not the case.  While all tubes worked well, the 5U4G tube provided the best overall performance with my setup.  The 5U4G tubes had just a bit more clarity compared to the 5AR4/5V4G tubes.  I also noted that the 5V4G tube seemed to have excellent clarity, but slightly (and I mean very slight) recessed presentation compared to the other tubes.  The best over performance (lowest noise, best clarity, depth, presence) was the MIL SPEC 5931 tube.

It's interesting that although the power supply was designed for primarily the 5AR4, the 5U4G tubes I tried all seemed to be just a bit better match for the unit.  The 5931 tube is absolutely a great tube, and provided an excellent match for the 5692 tubes with the Oppo.
 
PS: A thanks to my buddy for letting me borrow his stash of 6SN7's to audition.

[dminches]

My findings are quite different.  I found the 5692s to be dry and lifeless.  In comparison, I have tried metal base Sylvania 6SN7Ws and really liked them.  Right now I am using Tung Sol 6F8Gs and I am enjoying them a lot.  I haven't rolled the rectifier at all since I put in a black base Mullard GZ34.  Once I get my PS 9.9 I will be able to try others.
 

[Freo-1]

My findings are quite different.  I found the 5692s to be dry and lifeless.  In comparison, I have tried metal base Sylvania 6SN7Ws and really liked them.  Right now I am using Tung Sol 6F8Gs and I am enjoying them a lot.  I haven't rolled the rectifier at all since I put in a black base Mullard GZ34.  Once I get my PS 9.9 I will be able to try others.

Well, that’s why there is a saying in the UK: “Horses for courses”.  With my setup, the 5692 has an order of magnitude less distortion, as well as a lower noise floor.  So, each person’s setup will yield different results. 

[underdawg]

thank you for your impressions on tube rolling the oppo.
I have an oppo se 83. I settled on shugang treasure cv 181's in the player, and chinese 274b tube in the power supply- compared it with an original western electric 274 - due to the value of the WE I had to settle on the chinese one even though the WE was much better during the groups listening session.
I have not tried the 5692's yet but will when I come across a pair for testing.

[Freo-1]

thank you for your impressions on tube rolling the oppo.
I have an oppo se 83. I settled on shugang treasure cv 181's in the player, and chinese 274b tube in the power supply- compared it with an original western electric 274 - due to the value of the WE I had to settle on the chinese one even though the WE was much better during the groups listening session.
I have not tried the 5692's yet but will when I come across a pair for testing.

Definitely try the 5692 tubes.  From a engineering standpoint, they are without question a better quality tube compared to any 6SN7.  Just check out  the data sheets, and you will see what I mean.  So, given they are better made, designed to last longer, and are much less microphonic than a 6SN7, they SHOULD work better.
 
As one can see from the diverse opinions on the same unit,  not all will agree.  So, each person must judge for themselves if the differences are both noticeable and desireable.  In my application, the 5692 is much better.  The increased clarity, lower microphonincs, and lower noise floor are so noticeable that I will not go back to using 6SN7's.  Why people report such divergent opinions is one of mysteries of this hobby. 

[dminches]

Definitely try the 5692 tubes.  From a engineering standpoint, they are without question a better quality tube compared to any 6SN7.  Just check out  the data sheets, and you will see what I mean.  So, given they are better made, designed to last longer, and are much less microphonic than a 6SN7, they SHOULD work better.
 

The red base 5692 are meant to be run at lower voltages, which is why they are a long lasting tube.   I am not sure in what other way they are a better quality tube and I don't know if the engineering translates to a better sounding tube.  Take the 5998 power tube.  They are a superior design tube meant for computers.  However, they don't sound better than other power tubes.

In the end, the sound of the tube is user and equipment specific.  If you have a circuit which is designed for a high plate voltage then a 5692 may not be a good choice.  Again, it really varies by the design.

[dminches]

Here is a really good read on 6SN7s and their variations.  Again, YMMV.

http://www.dehavillandhifi.com/6sn7_vt.htm

[Freo-1]

Here is a really good read on 6SN7s and their variations.  Again, YMMV.

http://www.dehavillandhifi.com/6sn7_vt.htm

Excellent article.  Thanks for sharing that. 
It really does depend on the application.  My Oppo is either connected to a Pass Labs INT-150, or a DIY tube setup.  The explanations also provide some insight as to why the 5U4G (5931) tubes could work as well as they do with the unit.

[JG2]

Here is one man's opinion. His name is Len and he owns and/ or has tried a ton of 6SN7's.I have read many posts from 'Len' and he knows this tube!

I found this helpful but............YMMV

Ten 6SN7 Recommendations Having auditioned most 6SN7s (and there are a lot of them), I've decided to draft a list of ten "must audition" tubes. I chose these selections based on not only absolute performance, but also for sonic diversity. I am confident you will find a 6SN7 that suits your needs and/or preferences from the tubes listed below. Disclaimer: This is not a top ten list. There are many other excellent performers that missed the cut for various reasons. You may very well prefer a 6SN7 that is not on this list. And of course, this is all just my personal opinion. My goal is to provide a list of 6SN7 recommendations that provide excellent sonics but sound significantly different. Tubes are listed in alphabetical order (not by ranking). 

Brimar 6SN7GT/6SN7GTY: Lush. This is arguably the warmest, most "round" sounding 6SN7 produced. While in some systems, it may sound slow and bloated, in other systems, it sounds lush and wonderfully bloomy.

Ken Rad 6SN7GT/VT-231: Bass champs. The treble may not be the most refined, but both the clear and black glass versions provide world-class bass performance married with a sweet and seductive midrange. 

Hytron 6SN7GT: Neutral and fast. Need speed and clarity? Hytrons are very hard to top. This is definitely my personal tube of choice for detail and neutrality. I liken Hytrons to crystal clear streams. 

National Union gray glass 6SN7GT: Liquid and mellow. This tube is perfect to tame harsh systems or if you are looking for more open ambience from your 6SN7. NU GG is like floating on cloud nine. 

Raytheon 6SN7GT/VT-231 type II flat plates: Sweet PRAT. This tube is much like the Hytron 6SN7GT, but with a sweeter tone. Not quite as detailed or neutral as the Hytron, but arguably more seductive. 

RCA gray glass 6SN7GT/VT-231: Romanticism and warmth. The RCA gray glass possesses a full midbass and gorgeous harmonic richness, but yet delicate and detailed. When I crave the quintessential tube sound, the RCA gray glass is the first tube I plug in. 

Sylvania 6SN7GT/VT-231: Heavenly from the belt up. I call this tube the anti-thesis of the Ken Rad 6SN7GT/VT-231. While somewhat lacking in bass impact, the Sylvania 6SN7GT/VT-231 arguably produces the most beautiful midrange and top end in this family of tubes. Its midrange is clear and open, and the treble is smooth as butter yet unrivaled in its detail and spatial separation. Zero listener fatigue is guaranteed. 

Sylvania "Bad Boys" 6SN7GT (1951-1953): World class everything. Imagine the Sylvania VT-231. Now imagine it with bass in spades! What you have is Sylvania 6SN7GT from this era, often reverently referred to as "Bad Boys." This tube is often mentioned in "best 6SN7" discussions. 

Sylvania 6SN7W: Dynamics and slam. I can think of no other 6SN7 with more visceral energy then the Sylvania 6SN7W. From earth-shattering bass to the sparkling treble, all three versions of the 6SN7Ws provide a full throttle musical experience. The Sylvania 6SN7W certainly earns its place as a legendary 6SN7. 

Tung Sol 6SN7GT/VT-231 round plates: Absolute silk. This tube needs no introduction. The Tung Sol round plates are arguably the most sought after 6SN7 for its "organic rightness." -Len

[krustykat]

Some very good information here.  From the Dehavilland web site:

I will again caution everyone that various 6SN7 types have different voltage and plate dissipation ratings. The voltage rating refers to voltage across the tube's plate and cathode. To ensure good tube reliability you should probably run a tube at 70% or less of its maximum plate dissipation.

I'm curious as to what these ratings are  for the BDP-95 is and if it's acceptable for use with all of the NOS 6SN7 variants.

[Freo-1]

Some very good information here.  From the Dehavilland web site:

I'm curious as to what these ratings are  for the BDP-95 is and if it's acceptable for use with all of the NOS 6SN7 variants.

Good question.  Any of the NOS Sylvania tubes work great.  The Sylvania 5692 works well.  Some of the 5692's (CBS), sound good, but are not a good match for the Oppo. 
 
I've tried several other 6SN7's, and all of them work pretty well.  One thing I did notice was replacing the 5AR4 with the 5931 lowers the noise floor, and increases clarity from the unit.