Small or big tubes/valves for pre amp ?


Hi guys, have been thinking about going to a tube pre with a solid state amp.

I have a hybrid intergraded amp with small tubes in pre section, I am no expert in tubes, but know my way around the 6DJ8 / 6922 / ECC88 variants where I have preferred the Mullard tubes with my amp.

The pre amp that I have my eye on is the Don Sachs model 2, it uses bigger tubes and I am told that the bigger tubes have better sound than the 6922 variants I am used too.

Would appreciate if someone could enlighten me about the difference in sound signature between these tubes, I believe that Don uses 6SN7 tubes. http://www.dsachsconsulting.com/custom%20line%20stage.html

Thanks!



gryphongryph
That’s a generalization that large tubes sound better than small; it
depends on the implementation of the component. IMO, the 7308 which is a substitute for the 6922 sounds much better in terms of dynamics and realism. And most preamps use the 12AU7 due to the availability of NOS tubes, reliability, and good SQ in many different circuits.

The 6SN7, 6SN7GT, and its variants are very special; many types were ruggedized for military use in WWII, so they have excellent build quality. Their sonics vary greatly depending on the version and the manufacturer.
They have a large bottle and an octal base and may have the most pleasant and musical sonics of any preamp tube. They’re also excellent in the gain stage of amplifiers. Their greatest flaw, which is less common with small signal tubes, is that they can easily become microphonic. I admit it’s my favorite tube, but it does take more time and expense to find the right NOS due to the many different sonic signatures and also to test for low noise and microphonics.

I spoke to Don about purchasing his preamp, but it was a 3 month wait. There are many fans of his components online, not only because of the use of the 6SN7, but how it is implemented into his designs.

I have had some correspondence with Don, he seam like genuine nice person and very helpful, but of course he will not talk down his own product, and nor should he.
As I know the the flavor of many nos 6922 and they can be very different, I have no knowledge about the 6SN7 family of tubes, have heard also that they are a bit more fragile than the smaller tubes and do not last as long.
I like the Mullard sound, but with detail, am allergic to thin/shrill sound.
Tone, decay, timbre and natural voices is something I listen for in the music, I find that many amps and speakers today can replay a woman voice perfectly, sometimes spellbindingly good, but male voices not so good, often sounding neck up only, no chest!

I have my dream speakers now, and with my solid state amp I have problem with Van Morrison for example, sounding too thin, but with my hybrid amp he sounds fantastic!
Going to a tube pre into a solid state amp, a Belles or Van Alstine I am hoping to get more detail and maybe a more euphoric sound, also my hybrid amp makes me listen to music for hours at a time, my solid state amp, not so much! 
Go for it.
Use Psvane Globe 6SN7 from Grant Fidelity. You might want to ensure the pre can take their size. They are amazingly detailed.
Any 6F8G with 6SN7 adapters beats all 6SN7s IMO.
I personally like 12volt  tubes like 12AX7,12AU7,12AT7,12BH7...etc. better than 6SN7 . Like Lowrider said ,many of the  6SN7s that have good balance and Bass are microphonic.. like Ken Rad or Tung Sol.
The  vintage Sylvania 6SN7s can be  magical in all areas , except , they do NOT have good Bass. None of the Sylvania 6SN7s have good bass It is very weak . My amps which are the Granite Audio 864SR use 6SN7 in both V1 and V2.As long as I use something with good bass in V1              ( I actually use 6F8G) then using the Sylvania 6SN7-GT  in V2 works great  for me.


6SN7's have such a wonderful timbre and overtones. Since you are familiar with Mullard but like detail, Brimar is the better tube. It's a UK tube similar to Mullard, but with more detail and extension.

The Sachs preamp uses a cathode follower so the sound would be very clean and revealing. With my Rogue I would use a pair of matched tubes in the gain stage with a different brand of tubes as drivers. For example, Amperex in front and Mullard as drivers to add some warmth.



Those Granite Audio are excellent amps.

When using NOS 6SN7's, only buy from a dealer who tests for noise and microphony.
Military grade 6SN7s are tested to a higher level, but even these can become microphonic. Some versions are built with extra supporting rods to help prevent vibration.
Variants include 6SN7WGT,
VT-231, and any tube with a JAN prefix. Tubes from the 1940s and 50's have the best sonics but are  more likely to be microphonic. That's why you need to buy from a reputable dealer. I buy from Andy at Vintage Tube Services; he specializes in early tubes and tests for the best quality and performance. I have several 6SN7GT's which are from WWII era and are excellent performers. Of course, these tubes are at premium prices.



I buy from Andy also.
Thanks for the compliment on the 864-SR
I also replaced the coupling caps on the 864-SR with Jupiter copper foil....
Not cheap , but Very Nice sounding. I have some JAN CHS-VT-231- 2 hole black plates that are my favorites , but still they lack bass
I like the JAN-CRP-6F8G-VT-99.
Just to clarify, I like a bit more detail than I hear at the moment with my setup,  but don’t want the details thrown in my face so to speak, just want to be better able to follow different instruments in a classical piece for example, not detail for detail sake ;-)
@gryphongryph , I listen to classical almost exclusively, I hear what you're saying. Good soundstaging and 3D imaging are important to me with orchestral music. And I want enough detail to hear the instruments in a realistic way. 

I spoke to Don Sachs and I've read many user reviews; his preamp would be perfect for you. He said it's very transparent with a black background. I didn't go with his preamp because an Audio Note came up for sale at the time.
  You should check out some of the threads related to the Sachs preamp.

Using 6SN7's in a cathode follower design, be prepared to do some tube rolling. There are many different combinations of tubes that will get you the desired sound. I love tube rolling, but it can get expensive with NOS.


@grey9hound , I'm using Tung-Sol JAN-6SN7GT, black oval plates/ black glass (1940s). It took Andy a while to find these tubes. He's such a great dealer and asset; I put in an order for the T-S's and he called me when he procured them. They're one of the "holy grail" tubes.
   Before that, I was using KEN RAD VT-231 1940's in my preamp (also purchased from Andy). All his tubes are low-noise and I've never had any microphonics (knock on wood).

You're using Raytheon with an adaptor? What's the sonic signature of these tubes?

@gryphongryph I’m also a fan of Van Morrison. When I swap tubes, I use cut 2, Philosophers’ Stone from Back on Top, as one of my references. On this cut, he’s very close mic’d.

I have a tube preamp (6922’s) with a tube DAC (12AU7’s) along with a Class A solid state amp. I’ve probably swapped about 20 different brands of NOS tubes. Depending on the tube (and cabling), his voice on this cut can be hot or recessed or just right.   But, more than naturally reproducing a male or female vocalist, how is the PRaT?
Does a snare drum sound crisp?  It's a challenge to balance everything out.

I used to enjoy NOS Mullards 12AU7’s. Then, I went on a binge to seriously clean up the power to my rig. After doing so, the Mullards sounded overly warm with low resolution. It turns out they were masking a problem that I had with dirty power.

I totally agree with lowrider57.
That’s a generalization that large tubes sound better than small; it depends on the implementation of the component.
It would be ideal if you could audition a preamp in your system before purchase. Are there any audio clubs in your vicinity?

@steakster brings up a notion that I didn't think about; auditioning some preamps. We've only been referring to 6SN7's and the Sachs preamp, but there's a world of tube preamps out there. Many fine 12AU7/ ECC82 based designs in which equivalents can be rolled-in. There are so many premium NOS tubes available that take a AU7 design to a higher level. I've used 5963, 5814A, 7316, CV4003, CV491.

With that said, I love the 6SN7. IME, no other tube sounds like it. I'm on my second preamp based around it and no matter what the design, it sounds heavenly. 


I think this is very close to my observations here
https://www.audioasylum.com/messages/tubes/221750/6f8g-vt99-observations

The 6SN7 Tung Sol and the Ken Rads , that Andy had, at least one of the tube in the pair , was somewhat .
microphonic in my system. If you can find those that are not microphonic, the Ken Rads and the Tung Sol are the 2 brands that actually have Bass that I can live with , most all of the other 6SN7s do not ...IMO
This is what they look like .. this is not my  amp . Scroll down a little bit 
https://www.head-fi.org/threads/wa22-lets-roll-some-tubes-done-mod-burnning-in.451678/page-27

Thanks for all your inputs, really appreciate it.
I live in a far remote area so no chance to listen to other gear, with a pre amp that uses tubes it would give me more chance to tailor the sound for my preference, my speakers are bbc speakers, so easy to amplify, they are 8ohm and don’t go below 6ohm, but they are very revealing in tone and timbre, tone, timbre and space I find tube do better than solid state, and by changing the tubes I can get closer to my sound ideal.
For power amp I had planned to buy a Belles sa100 that I can get at half price (demo) but have also heard very good things about the Van Alstine set400, will see what I end up with, wish there was a solid state pre that sounded like tube ))) then no need for replacing tubes;-)
@grey9hound - I’ve been using 1940s, Tung-Sol(round plate/JAN CTL/VT-231) and Sylvania (6SN7W/JAN CHS/tall bottle/metal base) tubes, in my monoblocks for a couple decades(one each per amp). I’ve kept a stash of bottom-gettered, 1940s, Ken-Rads and Sylvanias, for back-up. They were specifically chosen, after listening to every one of the the top fifteen tubes mentioned on the following list, for their low noise/microphonics and lack of excess warmth/sugary glaze. Regarding Sylvania 6SN7s and Bass: that’s EXACTLY for what the tall bottle, metal-based Sylvania 6SN7Ws are known(slam). I’ve found all the(early) Sylvanias, well balanced from top to bottom, except for the short bottle 6SN7W, which(to me) was unlistenable. (http://www.dehavillandhifi.com/6sn7_vt.htm)
Andy even said the Sylvanias don’t do bass. I do not know about the metal base 6SN7W. They are as Rare as Hen’s Teeth
Try taking out the Ken Rads or Tung sols and run just the Sylvania in both spots if you are talking about running both Sylvanias in V1 and V2, I’ll bet your bass will suffer .I know Ihave  tried a lot of different Sylvania 6SN7 and could never find one that had great bass
If the Metal base 6SN7w have good bass , then they would be the only Sylvania 6SN7s that do.IMO
Do your amps use one or two 6SN7 tubes ? I am confused about that
"Do your amps use one or two 6SN7 tubes ? I am confused about that" As I stated: I’ve been using 1940s, Tung-Sol(round plate/JAN CTL/VT-231) and Sylvania (6SN7W/JAN CHS/tall bottle/metal base) tubes, in my monoblocks for a couple decades(one each per amp). Yes, that’s one JAN CHS and one JAN CTL("one each per amp"), at the same time. I collected a couple pair of the metal base and a couple pair of the slightly later(sans metal), tall bottle 6SN7Ws(which to me seem equivalent), before either became so rare. If you’d read the observations, contained in the 6SN7 comparison article, the author mentions the following: "It appears combining tubes like the VT-231s as voltage amplifiers and 6SN7Ws or 6SNGTA/GTBs as driver tubes you gain the strengths of all. Using one type seems to accentuate the tube’s weaknesses." I’ve found my Sylvanias very faithfully pass("well balanced") whatever information I feed them(including the bottom-gettered VT-231s). I chose my favs, based on my preference for tubes that don’t editorialize. They all(Sylvanias, Tung-Sols and Ken-Rads) also passed more ambient information, resulting in a wider/deeper sound stage, than any of the others I tried. Happy listening!
I'll take 6922 based gear all day over 6sn7. Not a fan of the 6sn7; they all have their own sonic quirks and colorations which is why you get recommendations to balance 2 types off each other. And if you have a high-gain circuit you'll likely run into noise/microphonics issues unless you go for the later GTA/GTB versions, which also aren't as sweet sounding. The only one I really liked sonically was Tung-Sol black glass round plate VT-231, but they're so hard to source with any decent life left - and again, good luck with noise. 
No, don't care for the GTA/GTB's.

I ran a single-gain-stage preamp with all brands of NOS 6SN7s and loved them (some more than others). But that design easily revealed microphonics. Using Herbies tube dampers sometimes helped.


@rodman99999
My whole point is ,The Sylvanias don’t have near the bass of the Ken Rads or Tung Sol 6SN7. Also Andy with Vintage Tube Services confirmed this for me . He actually told me that any of the Sylvania 6SN7s do not do Bass well .I agree with the article about mixing them. The main problem is that a Very High percentage of Tung Sol and the Ken Rads are Micrphonic. these are the only two 6SN7s that have great Bass.I have tried many many different 6SN7s. SO using a 6F8G with the 6SN7 adapter in place of the Ken Rad or Tung Sol , works great and gives you way more options
@mulveling
I agree with you 100%
Given the number of circuit designers, over the decades, that have chosen to utilize both nine pins(ie: 6DJ8 iterations) and octals(ie: 6SN7s), and the excellent results, that have been attained with both choices, has led me to believe that blanket statements are worthless. They only serve to prevent some from experimenting on their own, to find their personal preferences. Regarding Sylvanias and, "having Bass": I don’t want my tubes to, "have" anything of their own, but- to pass what’s presented them, without leaving their own footprints. The author of the 6SN7 comparison, made this statement(his first sentence): "Let me stress that the optimum tube for your system will depend on your equipment and how your ears judge the tube’s ability to reproduce live music." It seems some miss(or choose to ignore) those very salient(and universal) points(circuit variations/subjectivity).
@mulveling-  Mixing tube types in a circuit, to reinforce the positives of each, doesn’t ONLY apply to 6SN7s, but works in most any application.
Best preamp I have ever heard uses the 6N1P
@rodman99999
My statement should have been that the Sylvania 6SN7 do no re-produce bass very well. They are fantastic at almost Everything else
I think you understood what I meant. Take techno music for example . Most of it has a lot a Bass. I also understand that a lot of tube amps are not heavy hitters in the Bass dept.
Some people may not notice it too much... ????
But below is the real problem with 6SN7s  IMO as well as Many other's opinions too 

The only one I really liked sonically was Tung-Sol black glass round plate VT-231, but they’re so hard to source with any decent life left - and again, good luck with noise


This worries me a bit to hear, although I am no bass freak, I like tight bass, using a solid state power amp instead of tube power amp make any difference?
"...opinions..."   Exactly!
This worries me a bit to hear, although I am no bass freak, I like tight bass, using a solid state power amp instead of tube power amp make any difference?
'Tight bass' isn't natural bass, FWIW. It usually occurs in stereo systems where the woofer is overdamped.  6SN7s have no worries playing bass- no tube does- any tube can go to DC.

****************
IME/IMO, the worst of the 6SN7s are as good as the best of the miniature tubes. When you get a good 6SN7 no miniature tube competes. We use 6SN7s in all our preamps. We used to use miniatures in our amps decades ago, but when I discovered that 6SN7s were back in production, we switched over to them and never looked back.


Microphonics can be an issue, but that is true of all the miniature tubes too- in particular the 6DJ8/6922 family. BTW, the 12AU7 and 6CG7 are based on the 6SN7. The latter is literally a 6SN7 in a mini envelope; the former has half the plate area but similar geometry and so acts very similar on paper, but neither sound as good as the real thing.


Andy Bowman has been supplying our customers with good tubes for a long time.


We've been getting feedback on the TJ Music, Black Treasure Psvane and Sophia. They are universally liked, in particular the former two; with comments like "the best of all the NOS tubes rolled into one without the weaknesses". That's a pretty serious statement- but we hear it a lot. We have found though that the Sophias have been short-lived in comparison.
I use 6SN7GTBs in both my Schiit Freya (4) and my Dennis Had Firebottle SEP HO (1). NOS Amperex in the Had, NOS RCAs and Sylvania "chrome domes" in the Freya...utterly great sounding all around and I haven’t noticed any lack of bass with Sylvanias as this combo has slam for days. I do have a pair of REL subs in this system though...in the Freya The RCAs are in the "input" and the Sylvanias are the others, but it sounded great with all Sylvanias, just a little better with the RCAs. No dreaded microphonics, no hum, certainly the quietest tube rig I’ve heard, and, again, not a euphonic grease fest but clarity and tonal bliss (I think I just went too far)...efficient speakers make it work. All 6SN7GTBs certainly simplifies things for tube collection fun, and GL KT77s (2) round out the tubulars in this system.
I actually use the Shuguang Black Treasure KT88-Z in my Granite 864-SR. I also have  a pair of the Sylvania 6SN7GTA Chrome dome 3 hole black plates and 2  pair of Jan CHS (sylvania) 6SN7GT-VT231..
If i try to use the SylavniaGTA  in V1 and Sylvania GT in V2  or any combination of these in V1 or V2 .. I lack BASS.
I had originally ask for and tried the Ken Rad 6SN7 with the Sylvanias V1,V2... kiler bass , but Ken Rads were Microphonic. I then tried some Tung Sol Round black plates . They were also microphonic. I asked Andy to send me another pair of Sylvanias that have good bass... to use with the other Sylvanias , his reply was that none of the Sylvanias can do Bass as well as the Ken Rad or the Tung Sol, (cause once i heard the bass with the Ken Rads and or Tung Sols .. i had to have it)  Andy actually said that the only 6SN7 tubes that can do Bass like I heard and wanted was the Ken Rad or the Tung Sol  

So if using two Sylvania 6SN7, one in V1 and the other in V2, and it did not matter which Sylvanias (i tried. I tried all but the Metal Base ones) the Bass was lacking .
As a matter of fact most of the combinations of 6SN7s in V1 and V2 in those amps, lacked Bass IMO. ...unless i had a Ken Rad or Tung sol in V1   That was my experience with 6SN7 tubes.
Therefore i know use a 6F8G in V1 with the 6SN7 adapter.
https://www.ebay.com/itm/Tube-adapter-6F8G-to-6SN7-1-pair-/153299100833?item=153299100833&ViewItem=&nma=true&si=apYGBdYiWyN493VkmTacst7L9wQ%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

.
Just glad I stocked up on all my favorite 6SN7s and early 60’s, grey plate/shield, Siemens CCa’s(the CDP takes six), before they became unobtainium!  Again: Happy listening!