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Best of the Best 12AU7 (as posted to the Hong Kong Tube Audio Club)

From: ah_yung1d
Date: Sun Mar 16, 2003 12:31 am
Subject: 12AU7 Party - Result

We have a wonderful party, with champagne and perhaps the biggest crowd ever in Vintage Sound, to celebrate the launch of the Eastern
Electric MiniMax pre-amp designed by Alex, and also to attend the 12AU7 shoot out.

Just to give the background on the system used today :

Source : Jungson SACD player (as transport) + Micromega Duo BS DAC
Pre-amp : EE MiniMax with GEC CV4005 + Telefunken E80CC/N in 1st stage
Power amp : BBC AM8/6 KT88 PP monoblock
Speaker : Early 15 ohm Spendor BC-1

Due to the vast number of 12AU7 tested, we decided to use famous "Choi Kam 3-noter" track as seen and heard in the opening scene of recent blockbuster, "The Infernal Affair".

Because of the large audience and number of 12AU7,
I had to be full-time "tube changer" and stood next to the speaker in front of the
audience during the shoot-out. Therefore, I cannot provide any fair input to the comparison but just to summarise the comments I heard.

We have tested 17 12AU7 this afternoon and, apart from the Chinese 12AU7, all the 12AU7 test are what people will be regarded as Rolls
Royce or BMW grade. Some 12AU7 some members brought in are so rare that their very existence have never been reported.

And they are (in the sequence of appearance this afternoon) :

Amperex long welded plate D-getter 12AU7 (pre-1955)
Chinese stock 12AU7
RCA 1940's black plate square getter 12AU7
Valvo long plate D-getter ECC82 (pre-1955)
Siemens chrome plater double getter support ECC82
Marconi toast plate square getter wrinkle glass B329 (Mullard made)
Telefunken ribbed plate wrinkle glass square getter ECC82 (the most early version)
Telefunken smooth plate copper rod ECC82
Telefunken ECC802S factory certified version
Telefunken ECC802S generic version
Brimar long black plate square getter 12AU7
Brimar half box plate square getter CV4003
Hivac shinny black long smooth side square getter CV491
Gold Monarch B749
Mullard 10M gold pins 12AU7
Cossor wrinkle glass long welded plate square getter double support
12AU7 (likely to be Mullard/Ediswan made)
Lorenz welded plate circle getter 12AU7 (tested below standard!)

As expected, there is no single 12AU7 rated by all above all others. But a few did stood out from the rest. And the Best of the Best are (in no particular order):

- Gold Monarch B749
- Lorenz welded plate circle getter 12AU7 (even with sub-standard readings!)
- Mullard 10M gold pins 12AU7
- Telefunken ECC802S factory certified version
- Cossor wrinkle glass long welded plate square getter double support
- Siemens chrome plater double getter support ECC82
- Marconi toast plate square getter wrinkle glass B329 (Mullard made)

And the surprise of the day could well be the Chinese 12AU7. Even as it sound, by far, the least refined of all 12AU7 today, it actually gives an excellent bass extension and control to its merit!

Please provide me with your comment and let me know if I missed/misquoted any individual comment made today.

Again, let me thanks all of you for the participation of this great event.
Tim


From: vinylforever
Date: Sun Mar 16, 2003 12:30 pm
Subject: Re: 12AU7 Party - Result

Hi Tim

Many thanks for the excellent shoot-out which was so much fun. Are you planning to do one with 12AT7?

And congratulations to Alex for designing such a good pre-amp which is probably the best value for money ever. And those who loves tube-
rolling would definitely find it a heaven-sent!

It was really "ear-opening" to listen to so many rare 12AU7's. But at the same, it became very difficult, or almost impossible, to
remember how they each sounded afterwards.

If I were to pick three of the best, my somewhat vague recollection would lead me to the following choices (in that order):

1. Lorenz welded plate circle getter
Musical yet airy, detailed and refined, the pace and rhythm in the
music somehow became "just right".

2. Amperex long welded plate D-getter (pre-1955)
Well-balanced and musical.

3. Cossor wrinkle glass long welded plate square getter double support
Smooth, mellow, thick-sounding, might be the best for systems that
are a bit thin-sounding.

And if I were to pick a fourth one, it would be TFK802S, although unfortunately the Lorenz ECC82 is better in all those areas that the
TFK802S (used to) excel in! And personally, I don't hear a big difference between the ECC802S with the cert and the one without.
The former seems a bit more analytical, the latter more mellow in the mid-range.

Best regards
William


From: ayeung2002
Date: Sun Mar 16, 2003 3:16 pm
Subject: Re: 12AU7 Party - Result

Thank you vey much for such a nice party, especially the hard work of "tube changer" on MiniMax for our appreciation. We all had a
wonderful time.

All the 12AU7s tried were Rolls Royce grade that I could barely remember the small differnce among them. I would say every each of
them sounded great to my ears. If I must pick the tops, here are my choice.

1. Mullard 10M gold pin and Lorenz welded plate

2. Marconi toast plate square getter wrinkle glass B329 (Mullard made)

3. TFK802S both with and without cert

4. Siemens chrome plate

All the rest were very close. The stock Chinese 12AU7, ŒŒõ made, was really a surprise. Bass was tightly controled, except that high was
a bit rough. Stock 6X4 in MiniMax is already an NOS GEC round getter that new owners shall be pleased for quite a while before plugging
in some Rolls Royce grade tubes.

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