The Reference 6SN7 Thread

[sam6550a]

Sorry guys, what's mu? I have a wee collection of 6SN7's and 12AX7's/CV4033/CV4024 and 6N23p's. Obviously the smaller ones would be using an adapter but just checking they'll all be fine in my ordered Tor Audio Nick amp? ie the current required isn't too high for my transformer. I'm guessing the drop in 6SN7's will be fine but not so sure on the others. They worked fine in my schiit lyr 3 without issue, so I'm half assuming they'll be fine in the Tor

Edit: actually they may be 12AU7,will have to check later...

Mu = gain.

 

[jonathan c]

Yes, bought a couple of those for mudroom listening purposes.

However, have a Landsdale CBRZ Frankie that is exceptionally clean and detailed. Compares very well to my 6SN7W tall bottle.

Just received a cheap 7AF7... working up the courage to find out where it sits on the sonic mud mat map.

… was the 7AF7 as cheap AF ? …

 

[Isaacc7]

AFAIK, 7AF7 is round plate exclusively, not any 7N7. At least the modest sample size I've seen/heard.

Right, all 7af7 (and 6ah7 the octal equivalent) are round plate. NU briefly made some round plate 7n7 tubes early on. They are hard to find these days. Probably easier to find the likely equivalent NU round plate 6f8g. Here’s one of the round plate 7n7 from my collection.

 

[LobalWarming]

Right, all 7af7 (and 6ah7 the octal equivalent) are round plate. NU briefly made some round plate 7n7 tubes early on. They are hard to find these days. Probably easier to find the likely equivalent NU round plate 6f8g. Here’s one of the round plate 7n7 from my collection.

Nice find! Does it sound wonderful and round?

 

[Isaacc7]

I mentioned it earlier in this thread but it appears that the 7af7/6ah7 only had two versions, one black plate and another grey plate. I much preferred the grey plate but I only had one of each. I keep meaning to get another sample to use them in my push pull amp.

 

[Isaacc7]

Nice find! Does it sound wonderful and round?

Lol. The NU tubes are strange for me. I have yet to prefer them most compared to other tubes whenever I try them although I can’t pinpoint anything they do badly. I should try them again with some of the other output tubes I have accumulated.

 

[LobalWarming]

Lol. The NU tubes are strange for me. I have yet to prefer them most compared to other tubes whenever I try them although I can’t pinpoint anything they do badly. I should try them again with some of the other output tubes I have accumulated.

Me too. Have NU 6SN7s, 7N7, 6F8G, 6C8G, 12J5 and 7A4. The former don't get much ear time compared to others.

However, the $6/pr NU 7A4s are quite sweet and round sounding. Better overall detail and imaging than my Sylvania JAN 7A4s that cost 4x as much. Sometimes being a cheapskate pays off.

 

[Ranger Ron]

Lol. The NU tubes are strange for me. I have yet to prefer them most compared to other tubes whenever I try them although I can’t pinpoint anything they do badly. I should try them again with some of the other output tubes I have accumulated.

I find this post very interesting. I’ve been in the same position as you. I put the 6F8G NU in my preamp and I go, ahhh, that’s nice. A few days later they are back on the shelf. I forced myself to start using my lesser testing NU black glass tubes in one of my push pull amps, I’m glad I did. They’ve been in there for 4 months now.

 

[bcowen]

Yes, bought a couple of those for mudroom listening purposes.

However, have a Landsdale CBRZ Frankie that is exceptionally clean and detailed. Compares very well to my 6SN7W tall bottle.

Just received a cheap 7AF7... working up the courage to find out where it sits on the sonic mud mat map.

Agree on the Lansdales. The best of the best of the Frankies to my ears. This was my first one. $5.

Didn't go extensively into 7AF7 land. The slightly lower gain was not even noticeable in my amps. Nice sounding tubes, but I prefer the tall bottle 7N7's so I cut my adventure short. Didn't do much research on them either but wonder if like the 7N7's they were only made by Sylvania and NU?

 

[bcowen]

You need a thousand dollars premium adapter to match with your priceless tubes...

Or make your own to match the amp.

 

[Slade01]

Or make your own to match the amp.

What did you build that out of? Some 24 karat gold brick? Is this a super premium 5K dollar adapter?

For real, its very very nice - love how it matches the amp's patina!

 

[bcowen]

What did you build that out of? Some 24 karat gold brick? Is this a super premium 5K dollar adapter?

For real, its very very nice - love how it matches the amp's patina!

$5k? Now you have me thinking.

It's actually just a black plastic box that I converted from another adapter. Added an 18 gauge copper top plate that got the poor man's patina treatment and then self-stick copper tape around the perimeter. But then @Paladin79 upgraded my amp, so now I have to upgrade the adapter. This hobby is hard.

 

[Paladin79]

$5k? Now you have me thinking.

It's actually just a black plastic box that I converted from another adapter. Added an 18 gauge copper top plate that got the poor man's patina treatment and then self-stick copper tape around the perimeter. But then @Paladin79 upgraded my amp, so now I have to upgrade the adapter. This hobby is hard.

I could have your amp case looking shabby regardless of your taste, or lack there of.

 

[JTbbb]

I find this post very interesting. I’ve been in the same position as you. I put the 6F8G NU in my preamp and I go, ahhh, that’s nice. A few days later they are back on the shelf. I forced myself to start using my lesser testing NU black glass tubes in one of my push pull amps, I’m glad I did. They’ve been in there for 4 months now.

Are we talking about these? I know them as grey glass. Is there a black glass version?

 

[Renexx]

Are we talking about these? I know them as grey glass. Is there a black glass version?

No NU 6f8g is a different tube with round plates. It's unique as 6f8g in sound and construction.

NU 6sn7gt is available as black and grey glass. Grey version 1940s came first later succeeded by black glass in 50s. Sonically very different.

Different top mica.