[AllanS]

After 3 years of farting around I'm finally settling (90% sure anyway) on putting a Schiit Freya+ ahead of the single Aegir that I really love in front of the M4 Sapphires.  I've been tempted by better and more expensive but the reality is I just don't want or need to spend half again as much or more to be good enough.

I’m not asking for guidance specific to the Freya, just tube guidance that I’d use for the Freya. There's an overwhelming amount of info and number of options which is where I'm hoping for some guidance.  Please let me know your thoughts.

The Freya+ can be purchased without tubes or with an optional matched quad of JJ 6SN7 for $200.  I don't know much about tubes but figure better can be had especially if upping the ante a bit.

I'd like to budget $300-$350.  Matched pairs for gain and buffer but different tubes for both probably goes without saying.

Preference is accurate bass, rich mid-range, sound stage breadth depth/layering, and detailed but easy on the ears top end.  Woody acoustic strings, chesty vocals, breathy woodwinds, intimate chamber/small ensemble and such are my happy place. I have some type of treble sensitivity  - upper octave piano, violin, and flute can literally cause ear spasms.  So, while I like air around cymbals, I want to stay away from anything that'll accentuate what I understand to be the problematic 2-5 kHz range.

Brent Jessee's site has some characteristic descriptions www.audiotubes.com
From those descriptions the Tung-Sol oval plate (?) sounds like a good place to start: "dead quiet, accurate, detailed without being sterile, holographic sonics, and an amazing smoothness and silky depth to the sound". But this version seems to be much pricier than the garden variety GT/A/B.

The Sylvania sounds like something I want to avoid in the gain stage:"nice sparkle and air at the top". However, Gemini suggested the Sylvania GTB for the buffer and Ray Select (actually suggested the budget buster Ray Reserve) in the gain stage.  It also suggested the Ray Select is a better choice than Tung-Sol so I don't know who or what to believe.

I've spend some time looking at the sites below and found that many or most of the options would fit the budget but there are a lot of flavors to choose from! The hand holding that VTS offers is inviting but I would appreciate any thoughts or recommendations y'all might have.  Many thanks.

Brent Jessee: www.audiotubes.com,
The Tube Store: https://www.thetubestore.com/preamp-tubes/6sn7-tube-types,
Apos Ray Tubes: https://apos.audio/products/apos-ray-vacuum-tube-6sn7-select, and
VTS: https://vintagetubeservices.com/

[FullRangeMan]

Preference is accurate bass, rich mid-range, sound stage breadth depth/layering, and detailed but easy on the ears top end.  Woody acoustic strings, chesty vocals, breathy woodwinds, intimate chamber/small ensemble and such are my happy place. I have some type of treble sensitivity  - upper octave piano, violin, and flute can literally cause ear spasms.  So, while I like air around cymbals, I want to stay away from anything that'll accentuate what I understand to be the problematic 2-5 kHz range.

Your desires are unrealistic, too much specific, tubes are what they are, your best option are call Andy at VTS. You have to test various tubes in your system to know the valve qualities and defects.

Russian 6N8S Red/Brown base, NOS 1970s years>
Lots of air, much detail, very solid presentation.

RCA 6SN7GT NOS 1960s years>
Smooth, soft sound, well balanced with lots of warm,
All around excellent presentation.

AVOID
GE 6SN7GT NOS 1970/1980
Bland, a bit cold sound.

RCA 6SN7GTB NOS Button base, 1970s years
Bland, poor definition.

Russian 6N8S Black Base 1980s.
Low price at GSTube.com but a bit harsh, congested on complex passages. A great tube to Guitar amp, pedal effect, compressor or other Pro-Audio equip.

[Tyson]

NOS Tung Sols are the way to go, IME.  After that I would recommend Westinghouse.  If you want to cheat, you can get 7N7’s with an adapter.  Same sound but cheaper.

[mick wolfe]

It's virtually impossible to "predict" what current or NOS 6SN7 would work best in your particular set up. All I can offer is put the better part of your budget into the two gain stage tubes on the right side as you look at the Freya from the front. On another note, I'd be careful of 6SN7's with odd shapes as one can run into trouble with clearance considering the tube sockets are mounted well below the top of the chassis. FWIW, I use "ANOS" Sylvania GTB's in the gain position and GE's in the buffer stage. In the end, you'll just have to do further research and pick tubes that seem to fit your ear. This according to reviews of course. A roll of the dice for sure, but I've never been disappointed with virtually any of the NOS or ANOS tubes I've used the Freya. Maybe I've been lucky or simply have an ancient ear.

[Charles Xavier]

These Raytheon's have nice air on top and the midrange is gorgeous. Just purchased as a backup pair and came today. My original pair in use came from Brent Jesse but they are no longer listed on his site.

https://www.ebay.com/itm/236129408343

[Rusty Jefferson]

It's virtually impossible to "predict" what current or NOS 6SN7 would work best in your particular set up....

Spot on. Unfortunately, you aren't going to know until you try them and that requires an investment. Consider whether you may want to go farther with tubes in the future. Will this equipment be an endpoint or launching pad? If trying to keep control of the cost, I'd purchase it with the supplied tubes from Schiit so you can listen for a while to get use to it. Maybe after a couple months I'd buy 2 pair of the same type from a dealer, say RCA. Listen to those for a while  and after a bit, mix them with the supplied tubes in both positions. Then, if what you're hearing has peaked your interest, buy 2 pairs of something else, say Tung Sol and repeat the experiment. By the end of 6 months you'll have a better understanding of how this works. As was mentioned above, you won't necessarily be able to count on the exact same variations if you upgrade gear, though there are tendencies, like RCA tend to be rich and Siemens tend to have clarity.

FWIW, I only buy tubes from VTS. There is a premium but the tubes are always first rate and I've had no problem returning tubes that didn't make the improvement I was after so I didn't accumulate needlessly. If you don't hear any appreciable difference between the supplied tubes and 2 pair of NOS, you should be able to return them.