I bought a set of 4 6N23p tubes from a reputable on line vacuum tube store.
After about 3 weeks one tube had a low level hiss. I replaced it with one of the Audible Illusions 6922's that were over 2 yrs. old. About 6 months later another
(both line stage ) tube started getting hissy.
Huh, I thought these guys were supposed to last.
Questions:
1). I didn't order matched sets. Does that matter?
2) Putting in an older (obviously non matched) tube in the other spot, does that matter?
3) I've seen Type 2 and Type 3 on the internet, but no explanations???
4) I've seen several year old posts saying the Electro Harmonix 6922 IS a
6H23P tube. Are there differences? If not, does EH take them, test/reject
bad ones/keep only good ones).
5) I listen to my stereo once a week to once every three weeks for less than 2 hrs at a time. I therefore unplug the unit when not listening. When I turn on my stereo, I plug it in, wait a half minute then turn it on (muted)
.. My old C-J pre amp tubes lasted forever (12 ax7 -5 to 6 years)
I realize that this short of time for these two tubes is not typical,
but how long do YOUR Audible Illusions M3A tubes last?
Thanks,
Paul
After about 3 weeks one tube had a low level hiss. I replaced it with one of the Audible Illusions 6922's that were over 2 yrs. old. About 6 months later another
(both line stage ) tube started getting hissy.
Huh, I thought these guys were supposed to last.
Questions:
1). I didn't order matched sets. Does that matter?
2) Putting in an older (obviously non matched) tube in the other spot, does that matter?
3) I've seen Type 2 and Type 3 on the internet, but no explanations???
4) I've seen several year old posts saying the Electro Harmonix 6922 IS a
6H23P tube. Are there differences? If not, does EH take them, test/reject
bad ones/keep only good ones).
5) I listen to my stereo once a week to once every three weeks for less than 2 hrs at a time. I therefore unplug the unit when not listening. When I turn on my stereo, I plug it in, wait a half minute then turn it on (muted)
.. My old C-J pre amp tubes lasted forever (12 ax7 -5 to 6 years)
I realize that this short of time for these two tubes is not typical,
but how long do YOUR Audible Illusions M3A tubes last?
Thanks,
Paul
Here is a link that discusses this pre amp's propensity to eat tubes:
http://www.diyaudio.com/forums/tubes-valves/243709-audible-illusion-m3a.html
http://www.diyaudio.com/forums/tubes-valves/243709-audible-illusion-m3a.html
No.
No.
Slightly different construction and tone. Not a big deal.
That is correct.
Differences from what to what? If you are referring to tubes produced recently there are no differences
EH stands for Electro-Harmonix. That is one of the brand names used by New Sensor Corporation, the US outfit that bought the Russian tube manufacturing plant in Saratov, Russia some years ago. All the 6H23s are now made in the Saratov plant. They are now marketed as 6922 EH, they weren't marketed that way before the New Sensor buyout. So no, what you asked does not happen. They are not subjected to any special selection process, no.
Okay.
The AI is a tube eater, it runs through tubes at a very high rate. The c-j is not. The AI runs the 6922s very hard, and the only tube that lasts at all is the EH 6922 or its 6H23P-EB brothers. Most of my customers find the EH lasts about a year on the average, that's about it. Some last less, a few go a bit longer.
That's probably not what you wanted to hear, but it's the way it is I'm afraid.
I am puzzled by the statement that the 6922EH is the 6n23.
I have many examples of both and I have just had a good look at a pair under a big magnifying glass. There are clear constructional differences. They are definitely not physically identical. The 6922EH sample is dated 09 11 and the 6n23 is dated 07 82.
Cheers
Ian
I have many examples of both and I have just had a good look at a pair under a big magnifying glass. There are clear constructional differences. They are definitely not physically identical. The 6922EH sample is dated 09 11 and the 6n23 is dated 07 82.
Cheers
Ian
Hi,
Indeed there are.
6N23P-EV is no longer in production AFAIK.
The 6922-EH however is still being manufactured at the Saratov plant for New Sensor Corp's Electro-Harmonix division but it is not the same as the Russian
NOS 6N23P.
Instead it is much closer to the E88CC/6922.
Unbenanntes Dokument
Furthermore a 6N1P is not a 6DJ8/ECC88 either although it will often work as a replacement.
Ciao, 😉
Indeed there are.
6N23P-EV is no longer in production AFAIK.
The 6922-EH however is still being manufactured at the Saratov plant for New Sensor Corp's Electro-Harmonix division but it is not the same as the Russian
NOS 6N23P.
Instead it is much closer to the E88CC/6922.
Unbenanntes Dokument
Furthermore a 6N1P is not a 6DJ8/ECC88 either although it will often work as a replacement.
Ciao, 😉
Very strange because the inside of the illustrated 6922EH is quite different to the ones I have. In fact, having just compared a pair under the big magnifying glass, the JJ E88CC looks more like the one illustrated as it does have the getter fixed on both sides whereas the 6922EH I have only have it attached on one side and neither of them is the same as the 6N23 tubes I have.
That old chestnut!! I do wish people would stop trying to sell the 6N1P as an ECC88 et al equivalent. it is nothing like it. About the only paramater they have in common is mu.
Cheers
Ian
Hi,
That's rather mysterious indeed. Maybe EH made changes to the way they make their 6922s over the past years?
The document I linked to is from the hand of Jack van de Walle who's generally very well informed.
He could probably shed some light on the issue if someone were to send him an e-mail.
And then some...Most German vendors sell it as equivalent to the ECC85/6AQ8 which is closer but still not quite the same.
The Russian EF86/6J32P is also doubtful as a true equivalent of the EF86. I haven't yet had the opportunity to measure them properly but in my gear at least the noticeably/audible distort far more than say a Philips EF86. Don't even think of comparing these to a Z729....
Bottom line is, be ware of so called equivalents, they rarely are....
Ciao, 😉
That's rather mysterious indeed. Maybe EH made changes to the way they make their 6922s over the past years?
The document I linked to is from the hand of Jack van de Walle who's generally very well informed.
He could probably shed some light on the issue if someone were to send him an e-mail.
And then some...Most German vendors sell it as equivalent to the ECC85/6AQ8 which is closer but still not quite the same.
The Russian EF86/6J32P is also doubtful as a true equivalent of the EF86. I haven't yet had the opportunity to measure them properly but in my gear at least the noticeably/audible distort far more than say a Philips EF86. Don't even think of comparing these to a Z729....
Bottom line is, be ware of so called equivalents, they rarely are....
Ciao, 😉
Frank, the 6N1P is not recommended in AI preamps because it requires additional filament current in comparison
It's under FAQ,s on their site.
Regards
David
It's under FAQ,s on their site.
Regards
David
Just an FYI.
I was in contact with a New Sensor engineer back in 2011 and inquired about the 6922EH similarities to the 6N23P.
He told me that the 6922EH is (at least it was then) based on the 6N23Pi-EB.
I'm not doubting you that the physical construction may be different.
Here is a copy of the tube curves for the 6922EH he sent me. They look identical to the 6N23P-EV Russian tube curves on Frank's Tube Data Sheet site.
i have had good feedback from those who tried the 7dj8 in place of the 6922/6DJ8....YMMV..
don't know why, but i have seen the Russian 6H8 with filaments run at 5 volts
in a line amp with no apparent loss in sound quality...
don't know why, but i have seen the Russian 6H8 with filaments run at 5 volts
in a line amp with no apparent loss in sound quality...
The only obvious difference between his and mine is that his is the gold pin version and appears also to have gold lettering whereas mine is the regular version with black lettering.
Cheers
Ian
I did not intend to suggest they are not electrically very similar. I use the 6N23 all the time in 6922 circuits. I was only questioning the assertion that the 6922EH is a 6N23.
There are distinguishable electrical difference as well. The 6N23 samples I have are all more monophonic than the 6922EH samples I have. Their distortion spectra are also different. The distortion spectra of the 6922EH and the the JJ E88CC are also quite different.
Cheers
Ian
Difficult to say as it does vary with the chosen topology. Attached is a copy of the results of some tests I did on a whole bunch of different types of ECC88 back in 2011. They were configured in an SRPP topology which does tend to produce higher distortion levels than other topologies. You will see that the 6N1P is defiitely inferior but that the otheres are fairly similar. The main differences seem to be in the relative levels of the second and third harmonics.
Notice there are only small variations from tube to tube of the same type. I later did some other tests of a mu follower running at about 11mA and athough in each case the distortion was a lot lower as expected, there was a lot greater variation between tube types and also between tubes of the same type.
Cheers
Ian
Attachments
Thanks for the distortion spectra post.
That's quite interesting info (and unfortunate ) about the 6N1P.
Just curious, was the 6N1P you tested an EV version or do you think it even makes any difference?
Scott
That's quite interesting info (and unfortunate ) about the 6N1P.
Just curious, was the 6N1P you tested an EV version or do you think it even makes any difference?
Scott
Each line is a test of a different tube so I tested five 6N1P tubes. I cannot lay my hands on the actual tubes at the moment so I cannot say for certain which version they were - but I suspect it would not make any difference.
Cheers
Ian
Hi,
It won't make a world of difference but at least as far as European valves are concerned a different mix of materials was used for cathode coating which extended life expectancy.
Distortion spectra often show less 2nd order distortions which is one reason these were often viewed as "dry", less "lush" etc.
A prime example of this is the much praised CCa (a special E88CC destined for German Postal Services use) which exhibits far less distortion than any other ECC88 type.
E188CC are also much lower distortion types.
As far as the AI preamps go it surprises me that no owner seems to have drawn a circuit diagram to find out why this device "eats" valves.
I suspect it runs close to the maximum allowed dissipation of the valves which often gives excellent sound...for a while.
It may be a good idea to slightly bring down the heater voltage in order to reduce cathode emission as a first line measure to prolong the valve life.
Ciao, 😉
It won't make a world of difference but at least as far as European valves are concerned a different mix of materials was used for cathode coating which extended life expectancy.
Distortion spectra often show less 2nd order distortions which is one reason these were often viewed as "dry", less "lush" etc.
A prime example of this is the much praised CCa (a special E88CC destined for German Postal Services use) which exhibits far less distortion than any other ECC88 type.
E188CC are also much lower distortion types.
As far as the AI preamps go it surprises me that no owner seems to have drawn a circuit diagram to find out why this device "eats" valves.
I suspect it runs close to the maximum allowed dissipation of the valves which often gives excellent sound...for a while.
It may be a good idea to slightly bring down the heater voltage in order to reduce cathode emission as a first line measure to prolong the valve life.
Ciao, 😉
the Russian 6H23 seems to be better sounding, but the 6RRH8 i have were not microphonic, a high mu and transconductance will make them good cathode followers?
i also tried the 4KN8 and they seem to sound better than the 6RRH8....
i also have about a dozen Futaba 6RRH2's and some folks like them as a sub for the 6DJ8....
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