What made you change to a 6SN7 preamp?

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.  

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 

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.

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.

Each one has benefits that may attract a person to that type of sound.

Being very new to tube amps and preamps, your description of those tubes is a big help. Regardless of what subjectively pleasing sound tube electronics may bring, clarity and accuracy, not mellow, syrupy, embellished sound are essential. I bought the DS2 preamp upon strong recommendation by an advanced DIYer of tube and ss power amps over at diyAuidio.com. I will use it to alternately drive my First Watt F4 and J2 power amps for the new my > 93db speakers I am building. Perhaps one or both amps will prove to sound better driven directly by my DAC. But for the neutrality and accurate imaging I want to achieve, how much can this be optimized without consequence by with the choice of 6SN7 and/or other tubes with this preamp?