Shootout of Nos 6sn7 tubes

for the price of these tubes they offered a more tube sound than the new JJ Tesla 6SN7 tubes I was using.  More musical, more dimension, a nicer more relaxed sound in direct comparison in the preamp.  Have not tried them in my hybrid tube power amp yet or to the many 6SN7 tubes I already own.

My search for a pair of 6SN7/6F8G’s for a Supratek Chardonnay preamp continues. I’ve tried the Shuguang WE6SN7, early and late ‘50s CBS Hytron’s, and wartime National Union and grey glass Sylvania 6F8G’s. Of those, my favorite are the Sylvania’s, which offer a fine mix of sonic features I like, including a moderate degree of warmth.

Today I’m about 10 hours into a pair of genuine metal base NOS Melz 1578’s, sold and given initial few days burn in by someone in the States who had collected quite a few, resoldering the pins to ensure the best sound and long life. I have to say that this pair has great clarity, good tonal accuracy and a very nice sense of rhythm. Playing the old (1994) Sheffield/XLO Test and Burn-in CD, the 1578 renders the Doug Sax/Roger Skoff stage walk-around the clearest and most realistic I’ve heard over the years. However, what I haven’t heard yet is a sense of life or “alive.” I would characterize it so far as dry, uninvolving, boring in the sense of the music just passing by when not paying attention to the other characteristics (which I prefer not to focus in most of the time). Similarly, in the 6SN7 double blind shootout posted on Audio Head, three of the four panel members characterized the Melz as “dead” (the three liked the wartime grey glass RCA GT the best). Will have to see what develops, although “life” is not usually something that develops with burn in, but is either part of a tube’s DNA, or not.

If I could still edit my post, I’d note that the 1578 is highly rectifier dependent, at least in my set up. I’ve now tried three— potato masher, Fivre and Brimar 5R4GY’s with increasing warmth and presence, although w/o entirely overcoming the emotional distance that dryness gives the sense of. 

@highstream 
I'll be curious to read your thoughts after you play around with the tube rolling in your Supratek when you return to the stock tubes from Mick. I have really enjoyed tube rolling in my Cortese but could easily live with the preamp outfitted with the stock tubes.  They're really good and strike a very nice balance with all the important characteristics I look for when rolling tubes. 
Right now I tend to roll between CBS 5692s and Ken-Rad VT-231s. Only because I'm too cheap to step up to the Melz 1578s, the Psvane CV181s and I missed out on the Shuguang WE6SN7 plus tubes with the extra tall glass.
 I've got a lot of love for the 6SN7 and the Supratek!

if you try the shuguang black treasure cv181z IMO are like or better than the psvane

I missed also on the we6sn7, apparently great tube