Best 12AU7 Type Tubes for a Preamp

Best combo i’ve tried yet on my Jadis amp is a mix of RCA Black Plates and Telefunken Smooth Plates.

I yet have to try Amperex and Siemens Nickel Plates.

if this will help

british    mullards- warm, detailed, good dynamics

german   telefunken, siemens, open, airy, good head room, great sound top to bottom

holland   amperex, phillps good sound staging, 3 dimensional, good top end, bass may be a little sloppy with some. ( bugle boys are my favorite)

tung sol, rca , slyvania, electric harmonics or any of the us made tubes are all about the same to me and lower cost.  depends on your listening taste

talk with andy at vintage tube svcs in mich  616 454 3467 very knowledgable and helpful.   tell him damon from atlanta sent you....

Excellent thread. About two weeks ago decided to shuffle the pre amp tube line up on my Raven Nighthawk/Blackhawk modified, and pure magic was the result. (User experiences may vary) Front row went Volvo/Mullard 3 hole ECC81 (12AT7 equivalent), , row two CBS Hytron 12AU7( USA) , and row three Tungsram ECC82 (12AU7 equivalent) (Austrian).. This is more revealing than any combo tried yet. Tried all low gain 12AU7's throughout but lost details. Kicked the RCA clear tops out of the line up. Blurry (May have been an off pair.) For customers of Raven Audio, Dave and James are tube heads and provide personal help and tubes for their devotees. Very nice , tested, graded, and guaranteed High frequencies now are dreamy.

Just 3 days ago I got a package from Brent Jesse. It contained the 1960s Mazda ladder plates 12AU7 for my Backert Labs Rhumba. I installed them and kept the preamp ON for 2 hours and sat down for a serious auditioning. I am not going to say "blow out of water" or "I was blown away", etc etc, lest I jinx them. All I will say is that comparing the Mazdas to the Psvane ART series tubes is like comparing a 23 year old man/woman with a 40+ man/woman respectively. Hope you get it. I was told that they need at least 48 hours to sound nice. They sound nice right now. I am not going to keep them ON for a long time just to let them "burn in".

Yes, the Mazdas are pricey, but they are keepers. Mind you, the Psvane ART series are not bad at all. In fact of all the current production tubes, they are THE BEST. Only after listening to the Mazdas, did I realize that the Psvanes produce excess bass that is a bit bloated. The Mazda bass is very tight. Also the Psvanes do not extend and light up the treble the way the Mazda does.

I was recently asked a couple of questions related to this thread so I will partially answer here.

Q: Any update on how the new tubes sound in your system ?

• New Tubes: Amperex PQ 7316/ECC186 Holland Short Plate O-Getter 1965 Ct5. I have had these in the Hattor Tube Active Stage for a couple of weeks now and the tube stage is sounding the best it ever has. While the tube stage does not seem to be terribly sensitive to the tubes being used, the Amperex tubes seem a little more musical with maybe a little more definition than the new stock Mullards I was using. However, I could have lived with the sound from the Mullards.

Q: What changes does the tube buffer makes over the Big Preamp?

• I need to do more listening to answer this. As I remember it, I was impressed with the sound through the internal NewClassD op-amp active stage of Hattor’s The Big Preamp. The drive, dynamics, and clarity were very good but I need to make the time for a direct comparison with the Amperex loaded Tube Active Stage before I answer the question. However, as with the tube question above, my recollection is that I could live with either option, either the tube stage or the internal op-amp stage. BTW, my preferred gain with the internal active stage as I recall was +6dB. I will report back on this comparison after I listen some more.

Shssh. Don't tell anyone, but the 1950sTung-Sol 12AU7s are really terrific. They're as old as me and I just bought a backup pair so go crazy out there!

What kind of sound are you seeking?  Tube selection can add or subtract to what kind/color of sound you may be looking to achieve. I can recommend a source that was very helpful for me and that is Vintage Tube sales and Andy who you will  find at that location. I was a new to the tube shopping experience when I first ran into this site on a recommendation and found Andy VERY helpful. Experimenting with tubes can be - as with other things in this hobby- quite frustrating and I came to rely on Andy's advice to a great degree. Good luck. 

Congratulations on the Amperex 7316 PQs, they will be amazing for you. I couldn't find my notes, I think I sent it in by accident with a lot of tubes I'm having tested again. If you do more tube rolling, here is a good source, and Brent's tubes are above reproach:

http://www.audiotubes.com/6dj8.htm

@mitch2 

Good choice going with the Amperex PQ.

I sent you a PM.

@mitch2 Waiting for your impressions. I've Hattor Big pre with AMRG resistors. I'm thinking of getting its tube active stage.

Happy listening!

Just bought a matched pair of Amperex PQ 7316/ECC186 Holland Short Plate O-Getter 1965 Ct5 tubes that measure like new.   Should be here by Saturday.

No, I did not look for the Mullards.  I believe those short plate Amperex tubes are supposed to fall somewhere between the lusher Mullard long plates and box plates, and the more precise/detailed Telefunken and Siemens tubes.  I did like the PQ 7308 version in other preamps I owned some years ago.

@mitch2 

Sounds promising, you've used premium Amperex before so you know how great they are. Did you look for any NOS Mullards?

There is an ebay seller with over 1,500 sales at 100% positive feedback who has several pairs of strong measuring Amperex 7316 tubes at what I would consider reasonable pricing (less than $200 each).  I found two pairs and emailed the seller for advice on selection.

@lowrider57 - You are correct about Andy's availability.  I went to contact him this morning and found this message on his website:

Notice: Due to extreme demand, I am only answering the phone on Fridays and I am running about 2-3 months behind on filling orders.

I tried calling anyway and received a busy signal.  Even if I were able to speak with him, I am not patient enough to wait 2-3 months for delivery of two tubes.  However, I did also find the following message on Andy's website so at least there will be a future solution for people who want a faster turn-around.

Online ordering of select tubes is coming soon and those orders will be shipped within 2 days.

In the meantime, I will try contacting Brent Jessee or will look around at some other vendors. 

Interestingly, I was looking in the drawer where I used to keep tubes and found four matched, measured, and unused NOS Amperex JAN 7308 tubes that I no longer have any use for.  I cannot remember the preamp I had planned to use them in so I was surprised to find I still have them.  Some surprises are better than others!

@holmz 

Brent Jessee has a detailed description of NOS brands and their sonics.

@mitch2

If anything, I wouldn’t mind a bit more tonal density in the midrange through upper bass, but not at the expense of clarity. I am also curious whether I will hear any spatial differences with NOS tubes, like greater perceived dimensionality.

From this description I would recommend Amperex. But you’ve tried one of the best tubes out there, Amperex PQ 7308. It presents lush mids smooth highs, and a 3D soundstage. Since you like the new production Mullards, it seems as though you don’t want extended highs since these are rolled off on top. I suggest trying NOS Mullard long plates with either square or round getter. If not available, Mullard box plates CV4003. Brimar is another brand from the UK, same time period, that have more clarity, are less warm with a good soundstage. I've seen box plates CV4003 for sale.

NOS Mullards don’t have extended highs like Amperex or Bugle Boys, but have more realistic highs than new production. They’re also more detailed, have a lush midrange, and 3D soundstage which can be holographic in the right preamp. The problem is price and availability. After the shortage of Russian tubes this past year, inventories of US and European tubes have been exhausted, so prices are very high. What I’ve been doing is buying slightly used tubes that test as NOS. Mullards, Amperex, Telefunken will still fetch a premium, but if they are ANOS (almost or about NOS) they could last years in a preamp. Brent Jessee would be the first dealer I would contact. Andy at Vintage Tube would have the best stock, but there’s a 6 week wait at this time. Use Google to check out prices. Maybe others can suggest some trusted dealers.

@lowrider57 

After using the stock tubes, what kind of change do you want

Actually, there is nothing "wrong" with how it sounds now.  The sound is clean, clear, and there is no noise I can hear over what I get using the internal SS opamp output stage in the Hatter The Big Preamp.  Dynamics are good, as is the bass, but I don't typically split hairs over bass since I have dual subs so I can mostly adjust the sound of the bass as needed.  If anything, I wouldn't mind a bit more tonal density in the midrange through upper bass, but not at the expense of clarity.  I am also curious whether I will hear any spatial differences with NOS tubes, like greater perceived dimensionality.

I have been comparing the stock JAN PHILIPS ECC82 (12AU7/5963) tubes with reissue/new Mullard ECC92 tubes and have a slight preference for the Mullards.   I have used different tubes in the past in preamps by Lamm, NAT, Lector, BAT, and others.  In preamps using 6dj8/6922 type tubes, I gravitated to the Amperex 6922 PQ white label or Amperex 7308/E188CC white label.  I cannot remember which brands/vintage of 12au7 tubes I have used previously.

You need to decide which direction you want to go with the sound. After using the stock tubes, what kind of change do you want, more clarity, airy highs, more bass? There have been good tube recommendations, but they cover the gamut of sonic signatures as well as price points.

@lowrider57 is there a table or spreadsheet somewhere that lays it all out?

Yes best to try yourself.I have lots of different 12au7s and they are all good in their own way.Rft is cheap and a interesting tube.Super clear midrange.I like the amperexes,mullard,Telefunken.And there is quite a few I haven't heard.

@mitch2 

You need to decide which direction you want to go with the sound. After using the stock tubes, what kind of change do you want, more clarity, airy highs, more bass? There have been good tube recommendations, but they cover the gamut of sonic signatures as well as price points.

I prefer Brimars. Gorgeous midrange and a little more sparkle up top than Mullards. 

if the circuit can handle it 12BH7 is the preferred alternative to the 12AU7

5963 (industrial) and 5814A & 6189 (military) are drop-in replacements for 12AU7/ ECC82. 

I believe the best and most reliable are Mil Soec Mullards,

Rare and expensive, You will need to find a hoarder.

Mine were in the box wrapped in paper. They are all tested in an active unit before being wrapped.

well, cleartops are $60 or less a matched pair... not considered the best but just about appreciated.

if the circuit can handle it 12BH7 is the preferred alternative to the 12AU7

Mazda/Radiotechnique from France are really good. Great detail without being bright, and a very nice amount of tubey-ness and dimensionality. Bugle Boys too. 

Otherwise I think the current version of the Gold Lions is really good. I think they are easily the best of current production.

Amprex bugle boy

Mazda gray plates were pretty nice in my Luxman CL-38uC. 

I preferred them over the Amperex 7316, or Brimar CV-4003. 

I installed matched NOS Telefunken smooth plates into my Rogue M-180s two days past. They will need some break in time but so far I like them more than the JJ tubes I replaced so I anticipate I will like them more and more as time passes.

I also have a matched set of NOS Raytheon Black plates sitting in a box and will roll them into the M-180s in a couple months. I will also use these in my Rogue RP-7 some time down the road. 

Here is a good reference for the 12au7 rolling options.

"My favourites are NOS Mullards or Telefunkens."

Fascinating response in that the two are polar opposites sound-wise.

DeKay

My favourites are NOS Mullards or Telefunkens.

Mitch,

Definitely NOS only, nothing newer is even close…..70s &  80s, can be very very  good, 50s and 60s can be magical…..though with some tubes dating can be difficult.

I’ll find my notes and repost in next couple of days. I went through a manic phase and have tested at least 30 types (I think I still have 40+ pairs?), I also I had an amazingly thorough link I’ll try to find if I can

Psvane, fake gold Lion - out not even close Siemens ,Telefinken, Amperex,

Mazda, depending what your looking for in character, All pre 1970 for sure 

50s Sylvania, earlyRCA  , Phillips owned Amperex,and Mullard warmer nature 

Blackburn Mullard , lots of choices, Brent Jesse gives you 30 days to voice in your system and you can get 2-3 year warranty for extra $$.

This thread got me thinking about a pair of Viking RP61 tube preamps that was given to me from an estate some 20 years ago. Also included was a McIntosh MC240 amp and a MC20 preamp. I was given a nice Kennedy tool box with quality tools in it too so the fellow had good taste to say the least.

Anyway...the Viking`s were stuffed away until a couple years ago. I finally opened them up and ended up with a pair of Amperex Bugle Boys 12AU7 made in Holland with D7H printed on each of them.

I`m thinking I`ll bring them with me when I visit my daughter and son in law to try in their Rogue Sphinx II. Might be interesting to see what kind of change they make to the sound.

@mitch2  - Below is the link to Brent Jessee's website page for 12AU7's he gives impressions of the sound of different NOS 12AU7s which may help you match the tubes with the sound signature you prefer

https://www.audiotubes.com/12au7.htm

Thanks all - you have offered some really good thoughts and suggestions for me to consider, and thanks @dekay, the linked thread did have interesting and useful information.  

I live about an hour from Andy Bouwman • VINTAGE TUBE SERVICES, and I can get up there almost any time I want for my work so there would be no need to ship tubes.  I purchased from him long ago so I know how meticulous he is, which means higher prices, longer lead times, but almost surely a more successful result than dealing with mass market type sellers.  Since I only need two tubes, I plan to call him on Tuesday when he is next open and then purchase whatever he recommends.  As a bonus, there is some really good mountain biking very close to his shop!

As a last thought, this thread has reminded me of what a helpful, friendly community we have here - thanks again.

I've never been impressed with the RCA clear tops...or Mullards for that matter. The best I've heard are the German tubes, be it Telefunken or Valvo or whatever brand got stamped on the glass. The labels are meaningless for most NOS tubes and the codes should be used to evaluate where they were actually produced. The tubes that came out of Holland are very nice sounding, if a bit "sweeter" than the German stuff. Phillips had tube plants all over the place and they often weren't all that particular about what brand came from which plant. Tung-Sol produced some really nice sounding, smoked glass 12AU7 tubes that rival the European stuff, but are very hard to find and easily worth the extra scratch. 

In short, the German stuff is the best and worth the money no matter what brand is on the glass. The Holland made tubes (usually Amperex, but code specific) are very nice and sweet with good detail and worth a premium, followed by European tubes in general that were manufactured by Phillips. Mullard is distinctively warm sounding and often flashes when first powered up. American NOS are hit and miss across the board, with the exception of the Tung-Sol tubes that were terrific. Of the American brands, seeking out the military and commercial radio designed variants are the way to go. 

Back sometime in the mid ’90s, one of the best audio investments I ever made was retubing my 12au7 Cary preamp & my 6922 ARC amps via Andy at Vintage Tubes. He sold me a half dozen NOS Mullard 12au7s for the preamp, and the years that I ran that combination made for some of the best sound I have ever had.

That was a long time ago, however, with different amps, and my ears were a lot better, and I believe the room was more friendly than the one I am in now. About four years ago I bought some French 12AU7s (I think Cifte was the brand?) from Uncle Kevin at Upscale, and I did appreciate their sound, but things have never been as good as the way I felt about the equipment with Andy’s tubes. But I do need to defer to the disclaimer about amp & room & ear changes over the past 25 years.

Mitch2:

Here's a recent 12au7 thread of interest.

DeKay

Thank you everyone. The unit is (not actually but sort of) a preamp.  I have owned a lot of tubed preamps in the past and didn't think I would again but when I purchased Hattor's The Big Preamp to run in passive mode so I could have remote volume control and a display, I took a chance and also purchased their Hattor Tube Active Stage, which uses two 12AU7 tubes.  IMO, the unit sounds way better than it should for what it costs, and good enough that I am seriously considering keeping it in my main system.  The gain from my unit is +6dB.  FWIW, the Big Preamp can be run in passive mode, passive with the Tube Active Stage, or through its own internal NewClassD opamp output stage at a selectable  +3/6/9 dB gain.  The opamp output stage also sounds quite good.

Back to tubes, I like the idea of not having to rely on NOS tubes but wasn't sure if the Psvane or Genelex Gold Lion were even in the same league as the NOS offerings.  Back when I was using tubes in preamps years ago, it seemed everyone was after NOS 6922 tubes and the 12Au7/AX7 varieties were relatively inexpensive.  Times have changed.  Things sound good now, so I may just try the Psvane tubes and call it good, but I will also look hard at some of the reputable NOS tube sellers and see what I can come up with.

If you really can get the Amperex from a reputable source for the price you list, buy them at once!

In the world of new-production, Psvane outperforms Mullard and Genelex Gold Lion (I've tried all three).

Jump on Amperex ASAP!!

RCA clear tops and new issue Mullards sound good and have worked well for me.  

It's really circuit dependent how a tube will sound.  While asking for others' advice is a good starting point, this is something that you will have to experiment with first hand.  Buy a bunch of tubes and switch them in and out.  You may have a strong preference, or you may not.  Sell the ones you don't use.  Brent Jessee is my go to tube guy.

In my Backert Labs Rhythm 1.3 I use NOS 12SN7’s with the proper adapters in place of 12AU7’s and the results are wonderful.

Brimar CV4003 from Upscale worked great in my Rogue RP-1 and RP-5.
The RCA were brighter.
Genalex Gold Lion we’re pretty good as well. 

the PSVANE ART-S series are pretty tough to beat sonically.

If you are looking for more midrange warmth, the RCA black plates are a great choice. 

I've already expressed my preference for NOS tubes and to buy from a reputable dealer, but I must give props to Psvane. My preamp came with a Psvane 12AU7-S with gold pins and it had very nice tonal qualities. It presented a wide soundstage, but lacked the depth that so many NOS have. Nice top-end, not etched like some of the Russians, just a pleasant sounding tube that works very well when combined with NOS.

The prices you list for two of the three nos tubes is excessive.

The RCA cleartops shouldn’t be $40 each.

The Mullards go for around $175 a pair, unless they are the m8136 variant. Then they’re around $250 a pair.

If you can find a strong tested pair of the Amperex 7316’s (the earlier the better) for $150 each, I’d get those in a heartbeat. 

Just be careful who you buy from.   There is a dwindling supply of NOS 

I recently  bought a quad of early 50's RCA 12ax7 and 12au7 and they were not cheap.   Exactly as advertised,  they are true NOS  and test high.  

I recently bought a tube tester , those tubes were exactly as described but I learned that several tubes that were "NOS"  simply were not 

New production tubes were not exactly all that great. Some triodes were so far apart from being matched they are useless .   

Now nothing goes in my gear until I fully test and confirm they are strong and tightly matched 

New JJ gold pin 12au7 are very good.