What's the best 6NS7 tube you have tried in your Atma-Sphere MP-3 preamp?

My experience was with 6SL7’s in my Cayin Integrated Tube Amp A88T.

Sounded: Great, terrible, great again, future covered!

Made in 2001, I Bought it with used tubes 2019 on eBay with:

4 Gold Aero 6550 power tubes

2 Cayin branded 6SN7

2 Cayin Branded 6SL7 (identical size/appearance to 6SN7s)

all tubes tested good and matched strengths on my tube tester when received.

sounded darn good, I changed to 4 Matched KT88 Power Tubes,

JJ KT88 Blue on sale at Aliexpress, $98. free shipping quad matched $367.

I prefer them to 6550 and the amp’s ultra-linear sound to it’s triode option. I also like having the reserve power even though my 16 ohm horn speakers are incredibly efficient. My model, MK1 with 16 ohm taps, has dangerous internal bias adjusters, I paid VAS to do it, luckily I live only 35 minutes from them. MK2 version had meters and external adjusters, but they dropped the 16 ohm taps.

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2020 Yearly pre-holiday test tubes, all still ok, I mistakenly reversed a 6SL7 and a 6SN7, blew one 6SL7.

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tried a pair of matched NOS, from Brent Jesse, 6SL7WGT Sylvania Brownbase, military matched pair. different look chrome top I thought was smart.

hated their sound. Brent had me break them in (just leave on for 3 full days, no signal needed, 60+ hrs), still hated them.

Exchanged for matched pair of 6SL7GT General Electric, side getters, cylindrical plates, half the price, Brent gave me a full refund, I just paid the shipping.

Happy Days returned.

Since then, found a pair of used Cayin brand 6SN7 and 1 Cayin 6SL7 on eBay (I still have 1 good one), bought them for future use.

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TUBE LIFE: that’s 18 yr old OEM tubes with good matched strength. Signal tubes can last 10,000 hrs, Every year since 1973 I test all my tubes just before Thanksgiving, problems are more likely a short, occasionally a weak one.

seems aliexpress half off price is not that good, I got mine in 2020 from TubeDepot

Tube Depot KT88 Blue, matched quad set $280.

Anyone tried PSVAVE? KT88 Quad Matched $105.??????

...Or in any preamp that uses the 6SN7 ??

A friend of mine on another audio forum had gotten out of the 6sn7 business (meaning he no longer has the amp that used a pair of 6sn7s as driver tubes) and he made me an offer I could not refuse on several pairs of used and slightly used vintage 6sn7s.

The preamp I use 6sn7s in is a Cary SLP05, and since I only have pairs of these vintage tubes, I am running them in the left & right balanced input sockets. The first pair that turned my head were a pair of Tungsol VT231s; after those I sampled a pair of RCA black glass VT231s, and for quite a while after that I was hooked on those. By no means do I possess the golden ear, but the detail and imaging that I heard with those two tubes in those two sockets was incredible and mesmerized me.

A while down the road, my friend did some more house cleaning and sent me several more pairs (some that I haven’t even sampled yet). But the two pair I couldn’t wait to try out were the "Sylvania ’55 Bad Boys" and the National Union 6F8Gs (with adapters). With the "Bad Bots" the presentation struck me as being very up front and direct, and with the National Unions I felt the presentation was laid back and quite smooth.

I ran RCA black plates in my MP3 for a while (until they went noisy) and liked them very much. Nice lively 60’s rock and roll sound, if that’s what you’re into. I believe Tube Depot has them in stock.

I ran RCA black plates in my MP3 for a while (until they went noisy) and liked them very much. Nice lively 60’s rock and roll sound, if that’s what you’re into.

60's rock & roll isn't my thing, but I really did like those tubes in the front of my preamap in my system. However,  I would have to say that I like both the Sylvania "Bad Boys" and the National Unions better,