Thinking about buying a different tube preamp...

The Sophias came with the unit when I purchased it. Using a set of 1950s Sylvania JAN military grade 6sn7's now. Will test the Sophias Monday to see where they stand. I have my eye on a couple sets to try from Upscale Audio. Will contact them Tuesday. Busy at this time.

Brent Jesse is also a very credible source for NOS tubes - not affiliated just a very satisfied customer. Quality product and very easy to talk to and get honest insights from

Don't give up on those Sophias Abucktwoeighty. Their premium 6sn7s are rather pricey BUT they are hands down the most satisfying of all the 6sn7s I've used in my Supratek pre-amp and I've tried virtually all of them. Very linear with excellent extension. This is not to say I haven't had a couple of them go noisy on me before their time. Just make sure to purchase the 1 year warranty. I also have the same result in my Oppo Modwright with the Sophias.

"Don't think......feeeeeel!!!" 🙏

Many vintage 6SN7's from companies like Ken Rad, Brimar, and those silly metal base Sylvanias are microphonic. It's going to be very tough to get low microphony quality ones as we move down the road. The regular Shuguang 6SN7 sounds fine to me. The Russian ones are more durable. I cast a suspicious eye on some current production tubes that are being priced so high. I'm not sure how to reconcile the increase in price.

My inventory of vintage 12AU7's from Mullard, Brimar, Siemens, etc is about 13,000 pieces. My 6SN7 inventory that is TRUE low noise low microphony is about 500 pieces.

The reason is that most stocks of vintage NOS tubes comes from ex-military goods and 12AU7's were used extensively.