[Bill Baker]

I know tubes are very subjective and everyone has their personal opinions but I am curious what others have found. I am also aware that much of this is determined by the circuitry itself so results may very.

 I am fond of the 12AU7 and would like to see what tubes you would rate in the following three categories. New and NOS are fine but only 12AU7 and equivalent.

1) Very neutral, clean and articulate. Provides the most detail, air and extension

2) Warmer side of neutral but still good detail

3) Lots of body, very warm (maybe too warm)

4) Lifeless, stay away from.

[richidoo]

Bill O'Connell kindly offered me to try some vintage 12AU7s from his vast collection to fit my EE Minimax preamp driving Manley Snappers and Usher Be-20 with Grover IC and JPS SC. It is a very clean sounding high resolution system, I play classical symphonies and chamber mostly and some jazz.

I was a little embarrassed that didn't really like any of those precious jewels - just too much warmth, distortion, tonal inaccuracy. I eventually tried the stock EE branded chinese 12AU7s that come with the minimax, which I previously ignored. They are absolutely incredible. Crystal clear, extended in both directions, cheap, and most important to me they are tonally dead on. My system came to life, and the life of the music comes through clearly. Chamber music and vocals have perfect tone. They took a while to break in but low distortion balanced sound was evident from new. The highs smoothed out after 100 hours.

Previous to the EEs I tried RCA cleartop, they were nice on top, but weak bass. RCA black plate is nice all around but not as clear and low distortion as the EE. Tele's were too hot on top, weak bass. Amperex too fat. YMMV, of course, these vintage tubes are well loved, and I don't question their value in other systems. I am content to stick with this great little preamp due to the synergy of it with stock tubes in the rest of my system. I do wonder how the EE tubes would work in other AU7 applications. I have a GG Pre that I will try them in eventually.
Rich

[Niteshade]

I tend to like long plate versions of 12AX__ tubes. They seem to drive better and have a fuller bodied sound. I also like the 6SN7 since it's such a great general purpose tube and uses octal sockets. Ei is a great manufacturer of 12AU7's.

I know tubes are very subjective and everyone has their personal opinions but I am curious what others have found. I am also aware that much of this is determined by the circuitry itself so results may very.

 I am fond of the 12AU7 and would like to see what tubes you would rate in the following three categories. New and NOS are fine but only 12AU7 and equivalent.

1) Very neutral, clean and articulate. Provides the most detail, air and extension

2) Warmer side of neutral but still good detail

3) Lots of body, very warm (maybe too warm)

4) Lifeless, stay away from.

[Bill Baker]

Hello Rich,
 I have also found that NOS tubes are an expensive crap-shoot. By chance I happen to come across some "Baldwin" 12AU7s? that I do like but I have found my favorite to be current production. What I like so far is the Ei, JJ ECC82 and JJ ECC802 Gold pins.

I tend to like long plate versions of 12AX__ tubes. They seem to drive better and have a fuller bodied sound.

 For fuller bodied sound, there are many NOS AU7s that give you this but many will sacrifice control and/or upper end extension.

 It will obviously depend on the voicing one is looking for but for our products, there are two characteristics we are looking for. 1) Clean and articulate 2) Slightly on the warmer side of neutral.

[Brown]

try out some Chelmer tubes. new production tubes that are IMO equal to or better than the overpriced NOS tubes. I use 12AT7s and 12AU7s. Also own Tellies and Mullards prefer the Chelmers. Go figure.

[jgb0194]

www.diyhifisupply.com/?q=node/438

Haven't tried them, Bill, but Brian has sold me many nice Chinese-made tubes in the past. You may want to ask him for the real skinny on these -something must justify $95/pair for an "uber tube"!

For NOS, I've found the humble TungSol 5814W/WA the best in a shootout I did about 2 years ago in a Atma-Sphere MP-3. Lively and clean, with good tonal balance. Email me and I'll send you a pair.

John

[Bill Baker]

Thanks for the comments John. I know in the past that there have been a few Chinese 6SN7 tubes that Brian has sold to some of my Bella Extreme 100 amplifier customers which they really like and are still using.

 What I am looking for is feedback that I can pass on to my customers. We are receiving quite a few inquiries about tubes for our Purity, Musicale and Perfetto preamps (all utilizing 12AU7 tubes) and it's always good to have several opinions.

I know tubes are very subjective and personal as well as system dependant. My recommendations on tubes are always based on "from what I have heard from others" as what is to my liking, may not be to yours.

 The voicing of these preamps have been done with the JJ tubes/Purity and Ei tubes/Musicale & Perfetto.

For NOS, I've found the humble TungSol 5814W/WA the best in a shootout I did about 2 years ago in a Atma-Sphere MP-3. Lively and clean, with good tonal balance. Email me and I'll send you a pair.

 Thank you greatly for that offer but I would hate to be considered one to take advantage. I would not be looking to stock any NOS tubes. Only obtain feedback from users to provide customers aid in their choices.

[jgb0194]

No advantage taken, Bill. I have more than sufficient stash of 12AU7/variants. As you know I'd used this type in an Atma preamp until you floored me with your custom Audio Note M3 (can't wait to receive the upgraded 2 chassis version and report on it verus its earlier sibling). Believe me, I'm holding on to the stash while NOS supply continues to deplete - just checked inventory: some real gems in there!

The TungSol 5814 and the RCA 5814 "won" the shootout in my Atma preamp a few years back, and these tubes remain available at "reasonable" prices - unlike Amperex ECC186 and the like. They're only a small slice of the NOS 12AU7 family "pie", but worth listening to . FWIW, I only heard slight differences among those I evaluated - including the deified Amperex ECC186. Clarity and absence of high end sibilance were the main traits I listened for.

I really hope the TJ 12AU7 new production tubes prove worth their premium price. If one considers DIY HiFi Supply matching/weeding included in the cost, the value seems to me comparable to the crapshoot of NOS tube buying should their sonics be top notch.

Anyway, I'll mail you a pair of the TungSol and the RCA 5814s along with a pair of RCA cleartops. The latter have a lot more press out in cyberspace, so you'll have that along with the new production tubes you've used, for comparison.

p.s., Let me know your thoughts on using the NewClassD "super regulators" for my M3 upgrade - I know one digital gear modder who swears by them.

John

[Bill Baker]

Hi John,
 In all honesty I think the NOS 12AU7 tubes I am running now came from you along with some 6X5's

.... until you floored me with your custom Audio Note M3 (can't wait to receive the upgraded 2 chassis version and report on it verus its earlier sibling).

 This is coming along nicely. Just waiting to hear back from Peter on my order of the mains transformer. I am also building an external, dual mono power supply version of my Musicale preamp which is another that uses the 12AU7. This is the "Perfetto" which will be fully balanced as well. We had no choice but to go with an external power supply as the chassis is now loaded pretty good. Besides, there was no room left for the 100% Poly power supply filter capacitors.

Anyway, I'll mail you a pair of the TungSol and the RCA 5814s along with a pair of RCA cleartops.

 You are always a true gentleman John.

[Jon L]

1) Very neutral, clean and articulate. Provides the most detail, air and extension

This school of sound would be my normal preference

Siemens early long-plate 5814A.  Since these are pretty mucy unobtanium, Raythen 5814A (probably same as CBS 5814A) are also quite neutral and detailed/clean.

If even these are too much $, I can recommend Sylvania 6189 or Tungsram 12AU7 to try.  Often can be found cheap and in the neutral, clean school of sound and can "hit the spot" in many situations.   

Regular Siemens ECC82 tubes are in this school of sound but not quite with much magic. 

RCA Cleartops are either hit or miss, but if they work in a component, they can sound very clean. 

2) Warmer side of neutral but still good detail

Amperex 7316 PQ

Valvo 6067.  Ahh, if I could find some more...

Radiotechnique 6189  not exactly "warm" as in bass quantity, but sweet tonal warmth

Early long plate RCA 12AU7A's  very solid sonic signature and texturing.  Can hit the spot in certain systems but can veer into "maybe too warm" and darkish if mismatched.  My favorite of the RCA's are the almost black-plate like carbonized-plate ones.

3) Lots of body, very warm (maybe too warm)

Some of the Mullards fit the bill.  I like Mullard CV4003 better than the costlier Mullard M8136, which seems a bit more "stuffy" sounding to me.  CV4003 is lush but not exactly solid-body type of density; for that, the early RCA long plates are the way to go. 

4) Lifeless, stay away from.

Some of the much-later date tubes, including Raytheon 5814 late-production or Philips 5814A, etc. 

[jgb0194]

Bill:

As you well know, these tube preferences are really most dependent upon the preamp used; hence, ideally, you'll run a bunch of these through your "Perfetto" and the other preamps in your new line. I can only imagine how many hours you've invested in developing the line - maybe one or more of these NOS varieties will prove a great match and worth "discovering".

I'll call you about my dust-gathering "stash". Maybe time to send them on a road trip...

[TheChairGuy]

Bill,

I've yet to hear a good one yet (not that I've heard that many.....probably 6 different types over time).  They ranged from yawningly mediocre to pathetic 

If your gear can take 12BH7 (or 12BH7a) in its placve (as my amps can, fortunately) you're likely in for a real treat, tho 

Ciao, John