What made you change to a 6SN7 preamp?

What Is Your 100% Money Back Satisfaction Guarantee? Individual service and customer satisfaction is paramount to VTS. Every tube purchase is backed by my guarantee. If for any reason you don't like the tubes, you can return them within 20 days of receiving them with generous exception if notice is given. Tubes are guaranteed 90 days against manufacturing defects with the exception of 6DJ8 type moving coil phono input tubes and certain rare models that simply chew up tubes.

What Is Your Return Policy? A decent sized square box of at least the size they were sent in is proper. Any tubes returned in padded envelopes or "little flat-ass" (video tape sized) boxes will be returned to sender and charged accordingly.

Thanks @audioman58, I should have just went to the Vintage Tube Services website.

Andy will guarantee there are as new and work , return I don’t think so

Brent Jesse has a return to fit your audio for 30 days plus you can take out up to 2 year insurance with  Brent if a tube fails for little money 

I did not jump to a 6SN7 preamp for the tube but did so to upgrade at preamp and the one I picked happened to use 8 of them including headphone amp.  

It also uses a tube rectifier which also contributes to the sound as well as a resin encased R-core power supply transformer.  

I came from a 12AU7 based preamp (4 mu followers) and I never loved the sound despite lots of tube rolling.  I have several on hand from prior amps and preamps.  

The sound of the new preamp with stock EH 6SN7 was better than the outgoing preamp by a wide margin.  Much larger soundstage, a purer more refined sound that was more transparent and bassier at the same time.  

After several NOS tube and rectifier trials the overall presentation is just incredible.  

Lots of variables in the comparison but the 6SN7 tubes are part of the mix that got me here.  

Vintage tube service tests them in circuit, he has many different components to test them in.

@invalid , thanks for posting this. Andy has pics of all his testing gear on the website. Many years of purchases and I've never had a microphonic tube. Also the lowest noise of all my tube purchases. 

Ralph's UV-1 preamp gave me my first taste of 6SN7's. That small simple circuit produced a huge soundstage, music with weight, and layering of textures. I've moved on to another 6SN preamp and an Atma-sphere S-30 which uses (6) 6SN7 input tubes.

Ralph @atmasphere was my primary reasoning to try the 6SN7. No one is kinder, smarter and with incredible patience.  However, he hasn't been able to talk me into his class D AMPS yet.......

A week or two ago someone posted about removing the PreAmp from your system and go direct from the DAC . I tried for a week . It was clean, clear and had Dynamics  but........lacked  engagement . I of course but the pre back in the system yesterday . 

@invalid  ok, did not see it as a quote. Will try again, Thx.  

@mglik same question, above. And did the tube reseller offer you a return, refund?

Decooney you have to ask Mglik about the quad of psvane tubes I was just quoting his post about vintage tube service.

@invalid I paid $750 for 4 Psvane 6SN7 Globes and they were all microphonic.

$750 for a quad - where did you source them from? That’s interesting, you can buy a quad of PSVANE Cosor version globes for $259/quad. Can you share more...

It’s helpful to trace this back. FYI: info through an overseas distributor I learned of others having problems here in the USA with (some batches) of tubes that were packed properly (originally) coming from the Shenzhen factories. Then, arriving to some dealers, being unboxed from large lot boxes, then repackaged and packed loosely without cotton in smaller and less protective boxes. And, more subject to vibration and shipping damage to the buyers. Good tubes gone bad in reseller packing and shipping trying to save weight and shipping costs. Argh. It took TJFM and GDParts two years to figure this out and what was going on. Since then, I’ve been only buying the premium boxed pairs distributor-direct, and they come in their own individual foam insulated jewelry type boxes. Not in the individual cheap thin paper boxes loosely packed by dealer-resellers.

Ask the tube dealer reseller before they ship, how they are packed!  

Wondering how yours arrived, and for $750 sure seems questionable.

It was said that Vintage Tube carefully tests all tubes for microphonics.

Testing equipment has no way to do this.

The only way is to plug the tube into your component and wait a bit.

Tube sellers cannot do this. Hoarders may have the best tubes. But even then, you need to buy more than you need just in case.

I paid $750 for 4 Psvane 6SN7 Globes and they were all microphonic.

Vintage tube service tests them in circuit, he has many different components to test them in.

Can using various dampening rings such as Herbie's reduce or eliminate most microphonics?   Or is the microphonic the result of internal parts vibrations?  

@fleschler ,

IME, Herbies can reduce microphonics up to a point. Once a tube has gone full-on microphonic nothing can help. Tube dampers lightly touch the glass envelope and reduce resonances, but in many cases the sound will be affected. It may make the bass tighter in a good way or it may reduce the liveliness of said tube, making it sound dull.

It was said that Vintage Tube carefully tests all tubes for microphonics.

Testing equipment has no way to do this.

The only way is to plug the tube into your component and wait a bit.

True, but the dealer can listen to the tube using a high gain device like a phono preamp. This is what Kevin Deal uses. But this type of test only insures that the tube is non microphonic when it leaves the dealer.

For you 6SN7 fans, the VT231 equivalents can be a fun roll especially for rockers. IIRC, the Kenrads were a relative bargain when I tried them. Cheers,

Spencer

Andy @ Vintage Tube Services is a great guy and helped me decide on the best 6SN7 for my monoblocks.   Question-I have not had microphonic tubes in 50 years of audio gear.  For the past 20+ years, my pre-amp and phono stage uses subminatures which have a reported life of 100,000 hours, really thick (bomb use) glass and great sound.   Can using various dampening rings such as Herbie's reduce or eliminate most microphonics?   Or is the microphonic the result of internal parts vibrations?  

It was said that Vintage Tube carefully tests all tubes for microphonics.

Testing equipment has no way to do this.

The only way is to plug the tube into your component and wait a bit.

Tube sellers cannot do this. Hoarders may have the best tubes. But even then, you need to buy more than you need just in case.

I paid $750 for 4 Psvane 6SN7 Globes and they were all microphonic.

@sjackso1 "...I find the 6sn7 board with my Tung-Sol 6sn7GTB provides a good soundstage and a rich tone that you can listen to for hours. I swap different boards and tubes. Presently I am using a board with 2 Telefunken 12au7 tubes. I really enjoy the outstanding sound and flexibility this preamp provides."

This is an interesting ability to compare the two tube types using the same preamp.

Are you utilizing new "re-issue" TS 6SN7GTBs to compare to vintage Telefunken 12au7s?

I am running a Musical Design Chameleon preamp made by John Hillig.  The same well known and respected person that has made many people ecstatic with their systems.  The Chameleon has several daughter boards that snap onto the motherboard and provides an easy way to compare differences in tubes and tube types.  I find the 6sn7 board with my Tung-Sol 6sn7GTB provides a good soundstage and a rich tone that you can listen to for hours.  I swap different boards and tubes.  Presently I am using a board with 2 Telefunken 12au7 tubes.  I really enjoy the outstanding sound and flexibility this preamp provides.

"Unrelated to the thread topic but important to those looking to optimize their purchases regarding NOS tubes, Andy @ Vintage Tube Services is the guy. Give him a call, you’ll be rest assured he knows his tubes and upon ordering you’ll also find yourself grinning from ear to ear. He’s a passionate and perfectionist audiophile."

@tubegroover I did order some 12au7s and 6922s (Mullards and Amperexs) from Andy over 20 years ago and he did make me laugh. He had some strong opinions about manufacturers that wouldn’t be fair (to those manufacturers) to share. About 7 or 8 months ago I upgraded my 12AU7 pre to a 6sn7 pre, and I am about to upgrade the tubes. I have been putting off my decision of who to buy the tubes from, but I guess I’ll give Andy a call on Tuesday.

The only tube pre I have owned is 6SN7 tubes. I am happy enough to not look further. I have rolled tubes and right now nos  Sylvania bad boys sound great. My holly grain is an old pair of telafunkins but not willing to pay $500 per tube right now. Hear a lot about mullards and will be trying them next. What I have noticed is after about two hours of warm up the sound stage opens up and it is total bliss!

@atmasphere 

when you dig into it you find out that the variables I mentioned above were uncontrolled in the comparison. 

Your understanding of these variables, and your cautious way of taking variables into account when you make comments, make you an invaluable voice in this forum. Thank you.

Lack of control over variables is what leads discussions into sometime wild and fun or confusing and conflictual directions. Of course, the room is almost never mentioned as a variable in almost any discussion, but that of course is a hard one!

Unrelated to the thread topic but important to those looking to optimize their purchases regarding NOS tubes, Andy @ Vintage Tube Services is the guy. Give him a call, you'll be rest assured he knows his tubes and upon ordering you'll also find yourself grinning from ear to ear. He's a passionate and perfectionist audiophile.

I think you were reinforcing the point I was trying to make that it's not all about the tube? 

That is true. But if you work with tubes over time, you get a feel for what they do. More to the point though that in order to really compare what the tubes do, you have to make sure all the other variables (circuit topology, part quality, grounding technique, power supply design and so on) are put to bed.

We see this going on in the SET world all the time- SET fans say they've compared SET to Push-pull, but when you dig into it you find out that the variables I mentioned above were uncontrolled in the comparison. This makes comparisons invalid; all you can conclude at that point is you might prefer one over the other without knowing why that is if you're being truthful with yourself.

There are lots of possible tube to use. My favourite preamp uses 6GK5s.

@lowrider57  Thank you for relaying the story about that upgrade. It bears on my question directly. Very helpful.

@moofoo  Your example, too, bears on the question. And as others have said, there's no substitute metric for actually hearing it. Expense, tube, design are all relevant to the question, though. 

@big_greg  Thanks for your comment about the Herron. I need to sell something before buying anything else, but I'll keep my eye on that Herron. My Quicksilver got upgraded with Mundorf and Vcap caps and sounds pretty good. A night and day difference would really be the reason to change.

@atmasphere Ralph, I think you were reinforcing the point I was trying to make that it's not all about the tube?  Interesting to hear the 6DJ8/6922 was intended for use in TVs.

@hilde45 I don't have any experience with the Quicksilver preamp you have listed in your virtual system, but I think you'd find the Herron preamp a night and day difference.

Bought a used Ultraverve pre here on Agon, compared it side by side with my highly reviewed, more expense 12AU7 pre. Immediately sold the 12AU7 pre. Soundstage opened up, instruments and voices sounded more lifelike to me. I realized it was the sound my system was missing. Kara of Dehavilland built me a Mercury III and I rotate the two pre amps. I learned from this:1) more expensive is not always better 2) you can’t know what you are missing till you try it as it may be the sound you want 3) the preamp has a HUGE impact on your system. I am not saying 12au7 pres are not good, just sayin for my ears I like 6sn7 much better.

Thus, a question which controlled for this would ask whether your change in preamp was lateral in terms of construction quality and nevertheless there were improvements in sound which could safely be attributed to the tube?

I upgraded my 6SN7 ,preamp to another 6SN7 based preamp. It was a true upgrade in sonics, but one aspect remained constant, I heard the same characteristics that a 6SN7 provides. Rolling tubes used in the first preamp presented the same type of textures, imaging and soundstaging. There were, of course, many improvements in detail, noise floor, dynamics, and realism owing to the superior quality of the new preamp.

I continue to learn a lot from this thread. Thank you all so much.

@big_greg There's a Herron preamp listed used that I have my eye on....someone stop me before I ruin a perfectly good marriage.

Without naming designers, one shared with me he decided to use either 6DJ8 / 12Axx instead on his next version preamplifier because he felt the availability of good 6SN7 supply was dried up or hoarded away. That was 4 years ago.

Today we see more new production and updated 6SN7 / CV181 tubes showing back up from across the pond, more people testing them out, all hoping they last longer than a year or longer than any of their NOS stored away. I'm on that list myself. Not sure how this may or may not influence component designers moving forward. 

I was immediately struck by how much quieter it was, how much detail it had, and how it presented as good or better of a soundstage and had very precise imaging. 

It would be lovely if we could attribute the characteristics above to a particular tube; we could all just use that tube and then have state of the art. To address those characteristics has everything to do with operating points, bandwidth, parts quality, grounding, layout, power supply design and so on. The advantage of the 6DJ8/6922 is its linearity and bandwidth (it was used for instrumentation for example) so if you have a non-microphonic tube you'll do well. Since microphonics was not a concern in the applications for which this tube was designed (like television tuners) finding non-microphonic examples is a bit of a task.

I went the opposite direction.  I went from a 6SN7 based preamp to a 6922 based preamp.  I agree with many of the comments about the 6SN7 and happily rolled tubes in and out on a regular basis.  After spending many hundreds of dollars on tubes, I found 2 or 3 pairs that were my favorites, each of which had unique strengths, and enjoyed the ability to change the sound from time to time.

I was a bit apprehensive when I bought my Herron Audio VTSP-360 because I wasn't sure that things could get much better than my previous preamp, but I was immediately struck by how much quieter it was, how much detail it had, and how it presented as good or better of a soundstage and had very precise imaging.  Most of what I've read about it indicates that there are not major differences to be had by rolling tubes, and to date I have yet to open the case and am still happily using the stock tubes that came with it.

There's more to the preamp than just the tubes and Keith works magic with his gear.  I also own the Herron VTPH-2A phono stage which uses a combination of 12AX7 and 12AT7 tubes.  Again, magic happens with the stock tubes.

This is of course, a good point, but I really think, based on my experience that the 6SN7 tube is just inherently a better tube.  Its inherent virtues are such that a talented equipment designer (AKA Ralph Karsten) can do some magic.  I was really surprised when Dan Wright moved from the 6SN7 to the 6922 tube in his digital mods.  I have owned both the Modwright Sony HAPZ1ES which uses the 6922, and the Modwright Sony 5400 ES which uses 6SN7, and there is no question that the HAPZ1ES is a better piece of equipment.  Stock, it was arguably as good as the modified 5400.  After modification, the HAPZ1ES was substantially better, but it took a lot of money to get the top tier tubes from the 6922 family to really allow the HAPZ1ES to reach its potential.  Ralphs observation above that the 6922 tube wasn't designed for audio is not a small point.   If you buy a piece of equipment using a 6922, you better snatch up a Siemens and a spare.  Even the Telefunkens and Mazda tubes aren't in the same class as those old Siemens.  Forget about new production. 

I really think a case could be made that the 101D tube is underutilized, if one judges strictly on the the tube per se.   That tube, properly implemented, has virtues that are hard to ignore.  It has two significant downsides.  It is vulnerable to microphonics, and there are zero NOS tubes out there. It is all new production, and the only great new production tube is the Psvane WE, which go for around $700 a pair. 

If I were designing a preamp, I would work around the 6SN7.  As a buyer, I chose the 101D based Coincident and have no regrets. except when it is time to spring for new tubes.  

Thanks to everyone for posting. Just a couple of thoughts on what I've read so far.

First, clearly, people hear and can articulate a difference; I see patterns in the kinds of differences heard. This is helpful to me in anticipating *why* I might want to try a 6SN7 based preamp. 

Second, @decooney may throw some of the claims into some doubt with his statement:

another factor in responses so far may also relate to some people jumping up a level or two on design and improved parts quality with their next tube preamp purchase.

Strictly speaking, i.e bumping from something like a $1500 12Axx preamp up to a $3000+ 6SN7 based [a higher quality] tube preamp as a normal course of order.

Why? Because if some of you *simultaneously* purchased a better preamp AND a 6sN7 preamp, you could be mistakenly attributing the improvements in sound to the tube rather than the overall construction.

Thus, a question which controlled for this would ask whether your change in preamp was lateral in terms of construction quality and nevertheless there were improvements in sound which could safely be attributed to the tube?

I realize this is a very hard question to answer, for many reasons. But it is effectively the challenge implicit in decooney's observation.

Thanks lowrider & bigkidz!

@immatthewj these postings may be old, but so are vintage tubes.

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

@immatthewj

Go to ebay and buy sylvania 6SN7 green letters and the yellowish letter tubes.  Probably between $30 & $50 for a pair each.  Start there and see how your preamp sounds.   

Right, Andy lives for tubes. He tests all his tubes after he acquires them and adds them to his inventory. At the time of a purchase he measures  many different parameters of each tube as if they were to be used in his system. 

Brent Jesse and other tube suppliers do not have what private horders have.

What do you mean by this, I've had better luck buying tubes from vintage tube service than private sellers. Andy at vintage tube service won't sell you microphonic tubes.

I upgraded from a Cary SLP 90 (12AU7) to a Cray SLP 05 (6SN7) because 1) it was high time for a preamp upgrade, and 2) because Cary had one on their preowned page & I thought that the price was right.

I still don't think I have enough ear time into it to understand the pros and the cons

I am also still running with the Electro Harmonix tubes that came with it, and I have no doubt that those need to be upgraded, but there is so much out there I am overwhelmed with choices (so I have still done nothing)..

The MP-1 uses 6 6SN7s and 8 12AT7s.

After having microphonic issues with some 6SN7s I got lucky and got all excellent, quiet NOS Sylvania 6SN7s and great Mil spec 12AT7s for the phono stage. The improvement in SQ was dramatic and huge.

Brent Jesse and other tube suppliers do not have what private horders have.

If you can, find a horder.

@phantom_av    That's four less than my MP-1. Wonder why.

In building preamp amplifiers, the 6SN7 based tube in general is a warmer sound, more relaxed presentation, more dimensional soundstage with real mid-range beauty.  That being said, the 6DJ8/6922 is generally more dynamic, faster, better clarity, and more slam.  It is a more upfront presentation.

6DJ8s were not designed for audio and have trouble with microphonics. I find it far easier to find a low microphonic 6SN7. Microphonics tend to add an iridescence to the sound that is distortion, so despite the nice linearity of the 6DJ8 I learned to stay away from them.

The MP-1 from Atma-Sphere uses 6 X 6SN7 Tubes.

I totally agree with Bigkitz. I own and have for almost 20 years, a 6SN7 based preamp, bigger soundstage rich sound is a spot on characterization. I am currently listening to an upgraded  vintage preamp that is more preferable in my situation. As in all things audio, good, better, best is a parlor conversation not an indicator of what a specific listener is going to ultimately prefer. 

Here's a summary of my story. I had owned, used and enjoyed Naim equipment for several decades. When I got my Quad 63s and had a friend over he said "I wonder how these would sound with tubes..."

Another friend had always run tube equipment. At one time I'd been using a Dynakit ST-70 and enjoyed it a lot.

I started asking around on various fora about tube preamps. On one board (I don't even remember which one it was) someone who seemed to know what he was talking about recommended that I look at preamps based around the 6SN7 tube. I think he suggested a Don Sachs.

With little understanding of what I was even trying to learn I started to read up on the various forums. I was getting ready to buy a Don Sachs preamp when I ran across the "Preamp Deal of the Century" thread here. 

After much reflection I decided to order a Supratek. It was the first new, full price piece of equipment, other than phono cartridges, I'd bought in many years. It was worth every penny, even though it is the most expensive thing I've ever bought. I've never, ever had a moment of buyer's remorse. Not even a particle.

On other threads you might notice this comment, which now kind of represents my equipment philosophy. I want hand-made, technically superb equipment built by fanatics. Sole proprietors, ideally. Boutique-type stuff. Or hard-core dedicated experts and technical geniuses. I am less interested in equipment built by companies run by egotistical promoters who get a lot of press. I'm not saying their equipment isn't good. I'm just talking about my preferences. 

@dougthebiker , You know I had a Schitt Freya a few years ago and I miss it. I've bought pricier things and still think about the pleasure the Freya brought me.  The Freya was worthy pairing with gear even 5x its price. It's that good in my humble view. 

I have a Schiit Freya with 6SN7’s, NOS Sylvanias from Brent Jesse, They are quieter and create a wider sound stage - 3 feet beyond the speakers on each side. Never got that from the original Tung Sols or J&Js.

BTW, my TT cartridge cost 4X the Freya. I downsized from Gryphon monoblocks.  Don’t feel any burning need to move up from the Freya and it’s 6SN7s.

In perhaps the past 10 years or so there seem to be more preamps designed around the 6SN7. I’m on my second after using 12AU, AX7’s. I’ll agree with others regarding the tonal quality of these tubes, the spacious soundstaging, and the realistic textures of acoustic instruments. I use NOS exclusively in my preamp and in my amp, which uses six 6SN7s, due to their consistent quality and sonics (when you buy from a trusted dealer). Due to the increased pricing and availability issues of true NOS, I’ve started to take notice of the high quality of new production tubes. Now there will be no shortage of high quality 6SN’s with the availability of new production. For what it's worth, I’ve never owned a new production small signal tube that equaled the SQ of NOS.

nothing at all - no desire to jump on the overpopulated overpriced bandwagon when there are so many lesser known and better alternatives out there.for those that roll their own