Good Tube Selection for Atma Sphere S30?

Each A-S amp has one or two 6SN7 positions with the largest impact on its sonics; those positions vary by amp and vintage - email A-S or check the OTL forum on the Asylum to locate this/these on your amp. You will get the biggest dividends there and the differences are not subtle, at least on acoustic music. Of course other positions also affect sound, just not as much. There is, imo, no modern 6SN7 the sonic equal of a quality quiet NOS valve in A-S gear. Agree with Pubul57 about Andy at Vintage Tube Services - he takes his time but excellent product - best to call rather than write.

Here is a good place to start.

My NOS favorites:
1. Sylvania VT231 & 6SN7GT (especially the '52 green label w/ 3 holes in each plate)
2. Ken-Rad VT231 & 6SN7GT
3. RCA VT231 grey glass
4. Raytheon VT231

The current Shuguang CV181-Z Treasure are ok but also pricey - I found them soft in the bass compared to any of the NOS above. The Electro Harmonix 6SN7 are ok: slightly soft and warm, kinda like a Sylvania GTB, but the latter will last longer and its easier find quiet tubes. The modern standard Shuguang 6SN7GTs (not Treasure) that come stock with the amp are consistent, reliable and quiet, but sound rather mechanical to my ears when compared to NOS, and do not last as long. Stick with the stock Russian 6AS7.

Ralph, on your site you say that "more recently we have seen similar problems in reissue tubes marked "Tung Sol" and "Mullard". What kinds of problems? Who makes the 6sn7s you have for sale?

Jimothya,

Great link to 6SN7 information! Thank you

Clio,

I was using a Cary SLP-05 ( a left over from the 805AE monos I sold). I found a used Atmasphere MP3 here on the Gon and I am using that full time. Enhances the accuracy and realism of the S. I liken it to a fine dry wine, full of flavor but not overly sweet or lush; clean without solid state edginess

Pubul57, there are now Russian made, newly manufactured tubes marked 'Tung Sol' and 'Mullard" as the US importer has acquired the rights to those names here in the US.

What we have been finding with these tubes is very similar to what we find with the Electro Harmonix brand, as well as the generic Sovtek; if you put the tube on a tester it seems very likely that it will show leakage on the leakage test of the tube tester.

In practice, tubes with leakage can buzz if used in our amps. An additional issue has been that the life expectancy of these tubes seem to us to be really variable, some lasting only a few weeks. OTOH, we've seen US and Chinese tubes go over 50,000 hours.

I did inform the importer about these problems a good ten years ago. I was told that the 'next batch' would be different but so far that has not manifested, as far as I can tell.