[DenverW]

It all depends. People's gears / music genres / sound preferences / ... all come into play when choosing tubes.

I know @DenverW and @BobMonkhouse here prefer 12AU7 to 6SN7 on their Cracks.

Its true, but I have some caveats. I've found some pretty big swings in quality of certain 12au7. The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved. I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7. My current top 5 input tubes are:

1. amperex welded plate 45 degree 1940's d getter 12au7
2. 1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
3. CV6 mullard black plate (with adaper)
4. Siemens silver plate 12au7
5. CBS/Hytron E1148

So 3 of my top 5 are 12au7, and the other two are frankentubes. My favorite 6sn7 is the 3 hole sylvania 'bad boy.' I will mention that i've yet to hear both the tung sol round plate 6sn7 and the telefunken ecc802s. Just too price prohibitive.

As far as using lower impedance headphones with the crack, its my understanding that there will be bass roll off depending on the impedance of the headphone. So I think its certainly possible to listen to lower impedance headphones on the crack, but when you hit a certain song or type of music it will be more apparent.

@ bagwell359 I have an amperex e80cc, and I think the tube has great potential, but I'm too lazy to change the resistors to get the crack to work optimally with it. I was just too into trying other tubes to limit myself to either 12bh7 or e80cc types. The amperex is a rich sounding tube (to me, everything is imho!) that had great spaciousness. Airy rich; I like it a lot. As long as you don't pair it with anything syrupy it will work well. 5998, rca 6as7g, tung sol 6080, 421a...they all worked well. I would say that without that resistor mod the e80cc just didnt beat out the tubes the crack is optimized for. I'd like to one day make a three way switch for 12au7 type/12bh7/e80cc. I've read a bit about one or two others that have done this, but the skill level/effort level is above me right now .

On a side note, I'm having to modify the base of my crack. The kzk 100uf caps were just too big. Luckily, my next door neighbor is a wood worker. SCORE!

 

[cddc]

Its true, but I have some caveats. I've found some pretty big swings in quality of certain 12au7. The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved. I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7. My current top 5 input tubes are:

1. amperex welded plate 45 degree 1940's d getter 12au7
2. 1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
3. CV6 mullard black plate (with adaper)
4. Siemens silver plate 12au7
5. CBS/Hytron E1148

So 3 of my top 5 are 12au7, and the other two are frankentubes. My favorite 6sn7 is the 3 hole sylvania 'bad boy.' I will mention that i've yet to hear both the tung sol round plate 6sn7 and the telefunken ecc802s. Just too price prohibitive.

As far as using lower impedance headphones with the crack, its my understanding that there will be bass roll off depending on the impedance of the headphone. So I think its certainly possible to listen to lower impedance headphones on the crack, but when you hit a certain song or type of music it will be more apparent.

@ bagwell359 I have an amperex e80cc, and I think the tube has great potential, but I'm too lazy to change the resistors to get the crack to work optimally with it. I was just too into trying other tubes to limit myself to either 12bh7 or e80cc types. The amperex is a rich sounding tube (to me, everything is imho!) that had great spaciousness. Airy rich; I like it a lot. As long as you don't pair it with anything syrupy it will work well. 5998, rca 6as7g, tung sol 6080, 421a...they all worked well. I would say that without that resistor mod the e80cc just didnt beat out the tubes the crack is optimized for. I'd like to one day make a three way switch for 12au7 type/12bh7/e80cc. I've read a bit about one or two others that have done this, but the skill level/effort level is above me right now .

On a side note, I'm having to modify the base of my crack. The kzk 100uf caps were just too big. Luckily, my next door neighbor is a wood worker. SCORE!

Very nice overview of tubes for BHC!

You really scored for a good neighbor!

I wish I could find someone like this

 

[GreenNeedle]

Not sure what tube that is but the 6sn7 sounds very different from tube to tube. The newish tung sol 6sn7 that can be found for around 25$ is ok, but there are much better options. I'd go to the 6sn7 addicts thread for good recommendations.

It's an NOS Tung Sol 6SN7GT. Black base with 3226-13 also printed on the base.

Its true, but I have some caveats. I've found some pretty big swings in quality of certain 12au7. The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved. I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7. My current top 5 input tubes are:

1. amperex welded plate 45 degree 1940's d getter 12au7
2. 1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
3. CV6 mullard black plate (with adaper)
4. Siemens silver plate 12au7
5. CBS/Hytron E1148

So 3 of my top 5 are 12au7, and the other two are frankentubes. My favorite 6sn7 is the 3 hole sylvania 'bad boy.' I will mention that i've yet to hear both the tung sol round plate 6sn7 and the telefunken ecc802s. Just too price prohibitive.

As far as using lower impedance headphones with the crack, its my understanding that there will be bass roll off depending on the impedance of the headphone. So I think its certainly possible to listen to lower impedance headphones on the crack, but when you hit a certain song or type of music it will be more apparent.

@ bagwell359 I have an amperex e80cc, and I think the tube has great potential, but I'm too lazy to change the resistors to get the crack to work optimally with it. I was just too into trying other tubes to limit myself to either 12bh7 or e80cc types. The amperex is a rich sounding tube (to me, everything is imho!) that had great spaciousness. Airy rich; I like it a lot. As long as you don't pair it with anything syrupy it will work well. 5998, rca 6as7g, tung sol 6080, 421a...they all worked well. I would say that without that resistor mod the e80cc just didnt beat out the tubes the crack is optimized for. I'd like to one day make a three way switch for 12au7 type/12bh7/e80cc. I've read a bit about one or two others that have done this, but the skill level/effort level is above me right now .

On a side note, I'm having to modify the base of my crack. The kzk 100uf caps were just too big. Luckily, my next door neighbor is a wood worker. SCORE!

I do agree with you on the 12AU7 at least in my short experience and with no speedball added yet. There are large differences between some of these tubes. Stock (and least favourite) on the left to my favourite on the right:

 

[DenverW]

@GreenNeedle probably not a big deal overall, but if you’re rolling some other tube types I’d look at adding the speedball to help keep the current controlled. Is it going to hurt anything using 6sn7 in a non speedball crack? Probably not. Have I done it? Yep. Am I more comfortable using variant tubes with speedball added? Yes

I don’t think you’ll regret speedball.

 

[cddc]

I do agree with you on the 12AU7 at least in my short experience and with no speedball added yet. There are large differences between some of these tubes. Stock (and least favourite) on the left to my favourite on the right:

A very nice collection of European ECC82 / 12AU7 tubes there.

I saw: GE, Mullard, Philips/Amperex, Russian new production, Tungsram, Siemens, ? No print, Thorn (Brimar?), Mazda.

I figured one of the benefits living in Europe is the easy access to those European beauties - GEC, Mullard, Amperex, Telefunken, Siemens, Valvo, Mazda, Philips, ...

 

[GreenNeedle]

A very nice collection of European ECC82 / 12AU7 tubes there.

I saw: GE, Mullard, Philips/Amperex, Russian new production, Tungsram, Siemens, ? No print, Thorn (Brimar?), Mazda.

I figured one of the benefits living in Europe is the easy access to those European beauties - GEC, Mullard, Amperex, Telefunken, Siemens, Valvo, Mazda, Philips, ...

The No Print is an old Tung Sol and yes the Thorn? was sold to me as a Brimar and is (currently) my second fav. I have a few more to test out yet including a Marconi ECC 82 one that came yesterday TBH Out of that lot I only use the Mazda and Brimar. The Siemens is a little bright and neutral for my tastes and the Philips Miniwatt even more so. The Russian Tung-Sol is nowhere near the old Tung-Sol (no print.)

GEC is out of my price range. lol. I got my pair of Tung Sol 5998 for £40 (buy it now) off ebay. They appeared while I was searching so I was on ebay at just the right time. I wouldn;t have bought them at £100 each.

 

[DenverW]

The No Print is an old Tung Sol and yes the Thorn? was sold to me as a Brimar and is (currently) my second fav. I have a few more to test out yet including a Marconi ECC 82 one that came yesterday TBH Out of that lot I only use the Mazda and Brimar. The Siemens is a little bright and neutral for my tastes and the Philips Miniwatt even more so. The Russian Tung-Sol is nowhere near the old Tung-Sol (no print.)

GEC is out of my price range. lol. I got my pair of Tung Sol 5998 for £40 (buy it now) off ebay. They appeared while I was searching so I was on ebay at just the right time. I wouldn;t have bought them at £100 each.

You lucky dog! 5998 is a great tube

 

[DenverW]

Your tube porn has inspired me. What's the point of making a collection of you can't make people jealous on the forums? Although, there are plenty of people here that would put my collection to shame. In order of preference from top to bottom; 12au7 favorites and power tube favorites.

 

[GreenNeedle]

You lucky dog! 5998 is a great tube

Even better at £20 each shipped They were listed as used though and no "test readings" so how long they will last, who knows.

 

[cddc]

Even better at £20 each shipped They were listed as used though and no "test readings" so how long they will last, who knows.

At £20/ea shipped it's a steal, no matter untested or used. You really lucked out!

 

[cddc]

Your tube porn has inspired me. What's the point of making a collection of you can't make people jealous on the forums? Although, there are plenty of people here that would put my collection to shame. In order of preference from top to bottom; 12au7 favorites and power tube favorites.

Another great collection of tubes!

I saw:

Amperex, 5814A (likely RCA or GE?), Marconi, Brimar, Telefunken, Siemens, RCA, Amperex (guess from your ranking) 12AU7/ECC82's on the left,

and Sylvania 6080 Gold Brand, Bendix 6080, GEC 6AS7G, WE 421A on the right.

 

[GreenNeedle]

There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass. What do you guys reckon? Are these Frankens? Is it just to stabilise some looseness or a leak? What's that all about?:

https://www.ebay.co.uk/itm/KEN-RAD-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[chrisdrop]

There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass. What do you guys reckon? Are these Frankens? Is it just to stabilise some looseness or a leak? What's that all about?:

https://www.ebay.co.uk/itm/KEN-RAD-JAN-CKR-6SN7GT-VT-231-Black-Glass-Valve-Tube-Used-Tested-Strong/184418833662?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

FYI - the seller is a generally good seller. I don't know what is up with the sealant.

 

[cddc]

There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass. What do you guys reckon? Are these Frankens? Is it just to stabilise some looseness or a leak? What's that all about?:

https://www.ebay.co.uk/itm/KEN-RAD-JAN-CKR-6SN7GT-VT-231-Black-Glass-Valve-Tube-Used-Tested-Strong/184418833662?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

The brown sealant / filler should be the aged glue from a cheap fix to the loose base years ago.

Tube bases can become loose after decades of aging. When it happens, people normally fill some glue into the gap between the glass bottle and bakelite base to fix the problem. I had a couple of tubes that came with loose bases, and when I filled the gap with glue, I normally clean up the overflow of glue with Q-tips or towels.

Obviously the previous owner of the tube in auction didn't clean up any overflow of glue. When the glue oxidized years later, it became brown (or possibly the glue was brown itself).

Anyway, I personally think the previous owner did a really bad job on fixing the loose base, but the seller seems to be a good one from his track record.

 

[cddc]

BTW, you can clean up the mess with a blade. I did it once on a tube with some nasty brownish aged glue like that.