Rördjungel

[mikael2]

Tittade på lite rör och priser och inser vilken djungel detta är

De rör jag kollade på är varianten 12ax7/ECC83

Då finns förutom alla olika märken en massa varianter och årgångar

Smoth plate, ribbon plate, mm mm

En Telefunken-variant heter ECC803S som ska vara "The Holy Grail" inom denna rörvariant med pris därefter

Frågorna blir många...men hur vet jag vad som är bra och vad som är dåligt när jag tittar på olika varianter. Vems information kan man lita på?

Förekommer det inte mycket förfalskningar? Är det inte lätt att bli lurad?

Finns det nån bra sida där jag kan läsa lite om grunderna och olika rörtyper.

[Guest Rydberg]

Du kan ju titta på datumkoden på rören, där kan man se när de är tillverkade och i vilken fabrik. Telefunken rör ska ha en <> ingjuten i glaskroppen (i botten). Kolla EAR tråden så ser du tillverkarkoderna.

TFK ECC803S är mycket dyra, se denna länk ECC803S

Tfk ecc83 finns med på slät och räfflad anod, de priser jag sett så är de lika dyra men en del föredrar den släta anoden.

Det finns kopior av telefunken vet jag, på europesika marknaderna är det dock nog mest "the real thing" som säljes.

Jag har ju själv massa rör och dessa vet jag är orginal då de legat orörda i 20-30 år

Bra rör: Mullard M8137, Tfk ECC83, Tfk ECC803S, Tungsram ECC83 (för priset), RCA 12AX7 (dock med varierande kvalitet), CV492 mfl

[Guest Bernt]

TFK ECC803S är mycket dyra

Hehe, gissa vad jag inte har till salu...

[Guest Rydberg]

Har du dem?? om du ska sälja så sälj dem i USA Bernt för guds skull, du får 4000 sek styck!!

[mikael2]

Tackar för tipsen Rydberg

4000 styck Är de så ovanliga dessa rör? När eller under hur många år tillverkades detta superrör

[Guest Rydberg]

Jo, det finns ju bara dem som gjorde sen är det slut! Jag vet inte när de slutade tillverkas men jag gissar sent 60-tal. Kan kanske tillverkats en bit in på 70-talet.

ECC803S håller 100 000 timmar om jag inte minns fel så man behöver bar en uppsättning under en mansålder om man använder dem normalt.

Lite tester:

THE GREAT 12AX7 SHOOT OUT ?!"

I think some of you audiophiles may be interested in the admittedly

subjective results of some listening tests I recently performed on a

variety of 12AX7's and their clones.

Two amplifiers were chosen for the evaluation, both of which use 12AX7

type dual triodes in their input circuitry. Both are loosely based on the

Dynaco ST-70 and one features triode circuitry thruout. The amplifiers

chosen were the PAD ST-70 with ultra-linear outputs and the Kennedy Audio

ST-70T, a short description of each is provided in the following paragraphs.

The Purist Audio Design (PAD) is a elegantly simple design utilizing a

single 12AX7 per channel as a cathode coupled (differential) phase inverter

with no negative feedback - loop or current in the voltage amplifier

stages. This amplifier is well suited to this application since all of the

colorations and distortion products are audible due to the absence of

loop feedback, output linearity is good due to use of a limited amount of

current feedback in the cathode circuits of the output tubes. Tube

generated hum and noise are very audible in this amplifier, assisting in

determining the overall quality of the tube. Overall performance of this

amplifier is excellent into my AR-58S loudspeakers.

The Kennedy Audio Amplifier ST-70T (KA) utilizes a single 12AX7 voltage

amplifier shared between channels driving a pair of cathode coupled

12AU7A's which in turn drive the respective pairs of output tubes. Open

loop gain is high enough to allow for up to a 20 dB feedback margin

depending on selected output mode. Local current feedback is employed in

all stages to enhance linearity and to allow for precise control of overall

loop gain and bandwidth. Overall design philosophy means to optomize

circuit performance in the face of varying tube parameters. This amplifier

will drive difficult loads with ease and is relatively unaffected by

variations in load impedance. Overall it has a slightly different sonic

character than the PAD, and overall speed and linearity are better. Slew

induced distortions caused by inferior tubes are quite audible when

present.

The testing was performed under relatively uncontrolled conditions,

with a very limited sample size and with only two amplifier designs, even

so the information should prove useful in a lot of cases. Source material

was mostly CD with a smattering of analog source material. (CD's - Dave

Grusin's Baker Boys album, Charlie Brown, Harmonia Mundi's Tarantula, as

well as the Stereophile test CD among others, LP's were Lars Erstrand and

Brothers Four on Opus 3, Respighi's Pines/Fountains of Rome on Chesky.) The

CD player is a heavily modified 14 bit Philips, the turntable an AR with a

modified Mayware arm, the cartridge a modified Shure V-15, the pre-amp. is

one of my designs utilizing passive equalization, and no over all loop

feedback. Speaker cables are Apature Signature 500, and interconnects are

various home brew items... (I know that this is far from the ultimate -

but wait until I'm making a little more money....)

Please bear in mind that the rankings are really only scientifically

meaningful in the context of the specific electronics used, but that gross

deviations from best to worst will probably be audible in most tube

equipment presently used. Usual disclaimer: I don't have any connection

with any tube vendors, or manufacturers, and furnish tubes only as a

courtesy to my customers. The following is a ranking of tubes based on my

sonic preferences in the two above amplifiers, from best to worst:

1.) Tungsram ECC83/12AX7A (Hungary)

Substantially superior in the KA and PAD amplifiers, very quiet,

clean and detailed. Superiority particularly pronounced in the KA

amplifier where its low distortion and high resolution were very

obvious to all listeners. Detail present that was lost with all other

tubes, excellent sound stage, lots of "air" between instruments,

excellent harmonic structure, very neutral and cleaner sounding

subjectively than all others.

2.) Philips ECG 12AX7WA/7025 and Sylvania 12AX7A (USA)

Slight hum and hiss audible in PAD, dead silent in KA, very detailed,

clean, transparent, quick. Very good harmonic structure, and "air"

between instruments, excellent sound stage. Fairly neutral sounding in

KA. Good bass extension in both amplifiers. Considerable loss of

resolution as compared to the Tungsram tube above.

RCA 6681/12AX7A (USA)

Evaluated only in the ST-70T, this tube is an enigma, not particularly

well known, if its performance in the KA amplifier is an indication,

it is worth another look. It easily outperformed the Sylvania 12AX7A.

Very clean, excellent harmonic structure, inner detail, sound stage

and depth, freedom from overload effects under all conditions, quick,

open, lucid mid-range, extended well controlled bass, accurate treble

under duress. I would rate this tube as better than the Sylvania, but

limited experience prevents me stating this to be the case under any

other conditions...

3.) GE/Sylvania 5751 (USA)

Slightly quieter than the Philips in the PAD amplifier, dead silent

in the KA amplifier, very detailed, slightly forward balance in both

amplifiers. Quick and clean, detailed, lively, otherwise very similar

to Philips ECG above. Frequently outperforms 12AX7's in pre-amplifier

circuitry.

4.) Brimar 12AX7WA/CV492 (Britain)

Slightly noisier than any of the above tubes in the PAD amplifier,

very quiet in the KA, good detail, fairly neutral timbral balance in

both amplifiers, clean, good bass extension. Good sound stage depth,

very pleasant without being euphonic, more neutral than 5751. Less

noise would have put it in the number 3 position... Excellent overall.

5.) Mullard CV492/12AX7MC (Britain)

Relatively quiet, some hum evident in PAD, dead silent in KA.

Clean, neutral timbral balance, good inner detail and sound stage.

Good bass extension. Agressive, yet controlled presentation with

excellent harmonic detail and attack characteristics, dynamic with

no sense of strain in the KA amplifier. Very similar to the Brimar

and highly recommended.

6.) AR 12AX7B (India)

Very quiet, slight hum in PAD, not tested in KA, very solid well

controlled bass response, slight thickening of texture in the

mid-range and some brashness in the treble, good timbral balance,

slight loss of detail, overall very good.

7.) India ECC83 Allegrosound (India)

Structurally identical to the AR, and "Allegrosound Frosted", very

quiet, slight hum in PAD, silent in the KA. Clean, well balanced

sound, some thickening of texture in mid-range, slight brashness in

the treble. Good harmonic detail, somewhat lacking in depth, with some

high frequency distress on crescendo's in the KA amplifier. These

Indian tubes are very similar overall, but the AR is selected for low

noise. Good.

8.) Allegrosound 12AX7A Frosted glass envelope (Indian manufacture)

Significantly noisier than any of the above, substantial hum in PAD,

quiet in the KA. Very solid bass response, well controlled, slight

"chestiness" in mid-range, slightly brittle treble, good detail in

the PAD. Not so great in the KA amplifier, additional distress on high

frequency crescendo's and loss of harmonic detail are quite evident.

Not too bad, it seems to be a better match in inherently slew limited

applications.

9.) EI 12AX7A/ECC83 Penta, National, Procomm, etc. (Yugoslavia)

Fairly noisy and moderately high level of hum evident in the PAD,

fairly quiet in the KA. Substantial loss of detail in both

amplifiers, thick almost syrupy mid-range and soft, sweet treble.

Bass extension is ok, but loss of control is evident to some extent

in both amplifiers. This tube is good in the PAS-3 however.....

Quite inexpensive, but barely acceptible in some applications and

good in others. This is the same tube that some vendors sell for

$25.00 each and up - not worth the expense in my opinion, they sound

no better than the $2.95 version of the tube.... Not recommended,

except to those on a serious budget, or PAS-3 owners.

10.) Shuguang 12AX7A @#**?!?@#!!!! (Chinese)

Very quiet, some hum audible in PAD - one of the quietest tubes of

the lot.... Too bad it doesn't sound better. Rough, edgy almost

shrill sound quality in the treble regions, very dry, antiseptic

mid-range, lack of harmonic detail, shallow sound stage, bottom end

lacking in punch in both amplifiers. Fairly poor sound, but very

consistent and reliable. These don't sound very good in most pre-

amplifiers either... Not recommended. (Strangely enough some early

samples from around 1983 seem to sound better!?)

[Guest Rydberg]

Battle of 12AX7

We just completed another tube and hifi shoot-out tonight at my apartment. The main event is the "Battle of 12AX7" which is something I have tried to organise for the last two months or so. The objective is simply to try to find out what is the best of the best 12AX7. Beside this battle, we have also compared the Proceed CDD transport vs. the Sony DVP-S7000 + Theta TLC, and the ARC LS7 pre-amp with the Matisse Fantasy Line Mk I. Both Proceed CDD and Matisse are from leehc. We are also jointed by Mak, VH, Wilson, Andy Kong and Alan. The last two left just after the hardware comparison and before we start the tube shoot-out.

First we have is the comparison between the Proceed CDD and Sony DVP-S7000+Theta TLC. This is just to confirm what we have been saying for a long time. The Result? Of course, the Proceed won. But I did not really expect by so much margin. The Proceed is just far more musical and squeezing out far more information from the CD compare to the S7000+TLC.

The Matisse also proved superior to the LS7, but I have to tell you that the Matisse won with the help of no less than HK$4k worth of Telefunken 801S and Tungsram ECC83 silver pin tubes + HK$1k worth of MIT Z-cord. And the ARC LS7 is equipped with the stock Sovtek 6922 and of course, original power cord. But the LS7 response much less to tube change compare to the Matisse and I am very sure the result will be much the same even with all Sovtek 6922 replaced by Siemens CCa.

The reason why it took so long for us to organise the Battle of 12AX7 is because we want to compare the best of the best 12AX7 even produced, and these tubes are both extremely expensive and very difficult to find. Particular the Telefunken 803S, which is selling for around HK2,600 each in the market these days. Secondly, with the tiring experience of testing 16 6DJ8 last time. We have a number to informal qualifying rounds to pick out a number of weaker candidates first.

The final line-up for the battle are :

From leehc Tungsram ECC83 silver pin

From Wilson Mullard ECC83 long "dark gray" plate/square getter

Mullard M8137 circle getter/double support/toast plate

From VH Telefunken ECC803S double support/clear glass

Amperex Bugle Boy ECC83 long plate/square getter

From me Mullard 10M Master Series 12AX7

Brimar CV4004 long black plate/square getter

Noticeable tubes that have been eliminated in the qualifying matches are Telefunken ECC83 ribbed plate, Mullard ECC83 long "light gray" plate/square getter, Mullard M8137 big circle getter/single support/toast plate, Raytheon 7729, Mullard 7025, GEC CV492, Brimar CV492, GE 5-star 5751WA black plate and WE 5755/420A.

I believe the only noticeable omission is the Gold Lion B759. But this tube is so rare and expensive that it is quite irrelevant. We will compare it to the winner if some of us find it some days.

We used leehc’s Matisse Fantasy Mk1 as battle platform with following setup :

Speakers – KEF LS3/5a Piano

Power Amp – 2 x Audion Sterling EL34 Single Ended in mono configuration

CD – Proceed CDD + Adcom GDA600 + WE 93F

Test software were the usual gold Naum Starkman Chopin, Café Blue and David Oistrakh Vol 3.

We used the same blind testing and score system we used last time with the 6DJ8 battle and again, the aim is for each judge to rank all 7 tubes and compare all the ranking score to find the top winner.

And the result? Well, I think this time we have a clear winner, which is the Mullard 10M Master Series 12AX7. Perhaps a short history about this tube first. The 10M Series is a special selected type of , I believe, early 70’s Mullard, which is "aged", tested and then plated its pins with gold. The structure of the 10M 12AX7 is the same as the Mullard yellow label short plate 12AX7. But the sound is so very different. Each of this tube is guaranteed for 10,000 hours of usage i.e. the name 10M. It is quite rare and the street price in Hong Kong should be around the same as the Telefunken 803S.

I think the 10M won by giving the most all-round sonic performance and, perhaps more importantly, the most musical sound of all. The 1st runner-up, closely behind, is the famous Telefunken ECC803S, and this is the double getter support/clear glass version, which is generally believe to be the best version of all Telefunken 803S. This tube actually scored very high on most aspect, in particular the transience of music. But it lost out to the 10M in terms of musicality. What I feel is that the 803S tried so hard to get everything right and being the most "hifi" that it tend to communicate less of its music content compare to the 10M, which is simply more please to the ear.

Another noticeable performer, which came third overall, is the Mullard M8137. Like all M8137, it gives unbelievable bass and punch, and this particular version of M8137 is far smoother than all the other M8137 versions which make it so special.

Since I happen to own the winning tube, I should perhaps stop here and let the others comment on the result.

Another great tube evening. At the end, we all wonder what tube should we put to battle next time. Any suggestion, guys?

Creevy’s reply :

Last year I can remember that I have conducted a 12AX7 match with my friends. We drink the Cheateu 1983 and smoke our beloved Romeo Y Julita Churchill cigars besides listening to the music.

Here are the system that we have used:

Matisse Reference preamp (Mullard narrow waist CV 455 as the 12AT7)

Cary 801 ( W.E.300B date code 052, Amperex 211 & RCA red base 5691)

Technics SP10 Mark II turntable(Serial V tonearm & Koetsu cart.)

Tannoy Black 15' coaxial monitor

We have tested the following tubes also

Mullard long plate ECC83 (single getter support, double getter support, square getter of black and grey plate)

Mullard toast plate CV4004 (retangular getter, circular getter double support & large getter)

Mullard 10M 12AX7 (factory matched).

Telefunken ECC803s, ribbed & smooth plate ECC83

Amperex ECC83 long plate D getter with its famous MUSICAL sign

Brimar CV492 with black plate and retangular getter

Siemen three micas E83CC ( claims to be the TFK ECC803 version )

Gold Lion B759

CBS gold pins 7729

G.E. 5751 with 5 stars

We all feel that this match is absolutely exhausting, and there are different outcome. I cannot remember all the details but I still can quote partly of my preference:

1.Mullard toast plate retangular getter CV4004/6057

2.Mullard long black plate CV492

3.Amperex long plate D getter with factory code marked on the base of the tube.

I cannot remember the ranking of other but I am sure that the Gold Lion B759 and Mullard 1OM rank very low.

Actually I hope to make this test to be double blinded but still failed at last.

Anyway, I have recently purchased some interesting ECC83 below

a>Mullard CV492 long plate with D getter (though amperex but with factory code printed on the base of the tube)

d>Mullard BBC selected CV4004/6057 toast plate with retangular getter

c>Brimar CV492 with black plate and retangular getter PLUS the DIAMOND logo

d>Brimar Laboratory sample 6057

I am sure that these tubes must absolutely be competitive and will let you know for our result

Happy listening

[mikael2]

Intressant läsning!

Vad betyder det där "getter" som står i rörbeskrivningarna?

Mullard long plate ECC83 (single getter support, double getter support, square getter of black and grey plate)

Mullard toast plate CV4004 (retangular getter, circular getter double support & large getter)

[Guest Bernt]

Getter är en liten metallring som sitter inuti röret, när röret tillverkas sugs det vacuum i röret men för att få ännu bättre vacuum gjorde man så att man utsatte röret för starka magnetfält (eller var det mikrovågor) då började denna ring glöda av strömmen som alstrades och tog till sig de sista gasmolekylerna.

Jo, jag har ett ECC803S hemma, fast begagnat. Men håller dom så länge så är det väl OK. Fast det är inte till salu.

[Guest Rydberg]

Bernt har delvis rätt men även metalbeläggningen i rören kallas getter, läs nedan:

What is a getter?

Well, the glass enclosure that surrounds nearly all tubes (metal and ceramic enclosed tubes do exist) is evacuated; the air is pumped out leaving a vacuum. But no vacuum is perfect, some air will always remain. Air atoms will hinder the free movement of electrons inside the tube, but it is not too difficult to obtain a sufficiently good vacuum for the tube to function satisfactorily. Quite another problem is to ensure that it keeps functioning! The worst problem is the filament; even a low density of remaining oxygen in the tube will slowly but surely corrode away the hot filament. In a lightbulb, the hard vacuum is replaced by an inactive gas under low pressure, but that wouldnt do in a radio tube: The electrons would collide with the gas atoms. To make matters worse, glass is a silicon oxide compound; when it becomes hot, and tubes do tend to become hot, it will release oxygen atoms, and it will continue to do so during the entire lifetime of the tube. So something is needed that can absorb, get, the free oxygen atoms inside the tube, otherwise its lifetime will be deplorably short.

When you look at a normal radio tube, you will notice a metallic-looking area on the inside of the glass. This is the getter, and it is an easily oxydable metal, usually magnesium. When the tube is manufactured, the getter metal is placed on a ring- or frameshaped holder and after the glass enclosure has been evacuated and sealed, this ring is heated by induction. In normal air, it would burn like a miniature version of an old-fashioned photoflash, but in the almost total vacuum inside the tube, the magnesium evaporates and settles in an ultra-thin layer on the glass. Now, whenever a free oxygen atom (actually a molecule, O2, but thats irrelevant) comes by, it will form a magnesium oxide molecule and stay in the getter. This also means that you can get an impression of a tube's condition by looking at the getter: If the getter is grayish or white at the edges, the tube has seen better days. If the getter is all turned into a white powdery layer, the tube is air-filled and dead. Of course, a tube can have a perfectly healthy-looking getter and still be sick for other reasons.

[Guest Bernt]

Man lär sig något nytt då och då! Jag kan förresten rekommendera Hiragas bok om rörförstärkare.