https://lh3.googleusercontent.com/pw/ACtC-3c7y0kfiPiPhcKAedF_b8ONC22aHKTsDheEd51FmF8Omwv_hVyEck_W852...
Yesterday I got delivery of 1578 claimed to be made in 1973 (upper one in the photo).
But it appears to be same as the one that I got last week.
Both of them does not have shiny plate.
I compared the sound of both in Line Magnetic 508 amp.
They sounds almost same but slight high frequency noise that I noticed from the lower one is gone in the upper tube ).
Thus I had decided to keep the lower one as reserve and use the upper one as my "holy grail" of 1578 Melz for the time being.
I expect to get another Melz 1578 from Russia next Monday June 1st( fast DHL Express shipping from this Russian dealer only 10 day's within order) https://www.ebay.com/itm/Matched-pair-Extremely-rare-1578-6N8S-audiophile-6H8S-6SN7-Metal-base/273874731266?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
After I receive one next week, I will also do comparison.
https://www.ebay.com/itm/QUAD-FOUR-Matched-Balanced-Russian-6N8S-6SN7-double-triode-TUBE-NEW-NOS/312402083888?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
I also got delivery of Nos 6N8S tube yesterday.
After testing 1578 Melz, I also put pair of above 6N8s tube in Line Magnetic 508 for comparison.
Wow this 6N8S tube sounds very similar to 1578 Melz in overall signature while 1578 Melz give slightly more refined sound with wider and deeper soundstage.
But the difference between those two are not that drastic.
I can happily live with this 6N8s if I had not tasted 1578 Melz .
I saw the letter Vi71 on the bottom of this tube, thus it could be made in 1971.
https://lh3.googleusercontent.com/pw/ACtC-3d6V72LNg7nKRCgdFBsk8dIbfv8BHalFGAY4vgIb5epdveAY00rkFhkpOT...
i also have new production 6N8S stock tube from Schitt Freya+ pre.
They looks similar except red logo in new production tube.
I had done comparison of two tube in LM 508.
Although both of them have similar signature of sound with full bass and sweet treble but new production tubes has some veil and lacks air compared with vi 71 version.
After comparison of two 6N8S tubes, I was back to 1578 Melz.
Everything sound more refined and impactfull and wider and deeper soundstage than both 6N8S tube.
To me 1578 Melz is "holy grail " of 6sn7 tube.
But 6n8s tube named vi71 Nos is a very nice value at 46$ per quad is a steal (best value overall).
I had liked Raytheon Vt231 which cost me 65$ as excellent bargain, but this 6n8s may have gone farther as performance to value.
Thus I had ordered one more quad set of 6n8s tubes just in case.
It is time to finish the shootout of 6sn7 tubes.
1578 Melz is the King of 6sn7 with nice decay, full bass, sweet treble, widest and deepest soundstage.
TS, Syl, KR, RT and RCA Vt231 are just in second tier but they are all excellent tubes that I can live happily.
6n8s vi71 that I got yesterday is half notch below Vt231s made in 1940s and best value at 46$ per quad.
All 6sn7 tubes made in 1950's are quite good but they have no more room to play in my system.
They will be in in storage until I decide to sell them.
