Whats up with JJ signal tubes?

[Response Audio]

I like the sound of the JJ signal tubes and have been using a lot of 12AU7 and 6922 types. It seems that almost 50% of the JJ's I have brought in become noisy within only a few days. Anyonne else experiencing this?

[richidoo]

Yes, that's been my experience also, with both power and signal tubes. It's really a damn shame, their tubes can sound truly incredible, but of course, nothing that beautiful ever lasts.

[DaveC]

I swore off JJ tubes after a 5ar4 arc'ed over and took out a resistor in my old Anthem preamp. After researching uncovered a lot of stories about noisy or unreliable tubes I have not used JJs anymore.

[Response Audio]

That is a shame. They are very good sounding tubes for current production. I had always read about the troubles with JJ power tubes, especially some pin issues.
I gues i'll have to go with EH to supply with our Musica Bella products as I can't have half the tubes I send out go bad with a week.

[sleepyguy24]

Evening Gents

I'm really sad to hear you all have had issues with JJ signal tubes. I bought a pair of matching and balanced JJ 5751 tubes that came from Doug's Tubes early last year and they are sounding great in my Jolida amp. Maybe because Doug tested them out they are not noisy or are having problems? These have been used for a couple of hours a day for some time now and they have not become noisy or anything of the sort. (Knock on wood.) I don't think mine have a date code but I'll check.

Also from an old post on Audio Asylum I think even Jim McShane won't use JJ tubes. I guess I got lucky with the ones I got.

[mdfoy]

In my case, longevity is not a strong point in JJ tubes. I have found that new issue Psvane and Genalex to be OK. The sound quality of the tubes may not be on par with NOS in some respects, but longevity and quiet are very strong suits. I have found the Genalex B749 to be really nice.

Now, NOS CBS Hytron 5814 and organ stock Raytheon Blackplates sound very good with the Musica Bella. 

[JBryan]

JJ's QC and reliability have always been questionable. OTOH, they sound pretty good when they work and are inexpensive compared to other new production brands. I've bought gear with JJ tubes installed and only had a couple of failures (driver and power tubes) but that's a couple too many in my book so I tend to avoid them and I would immediately replace a rectifier rather than take a chance with the consequences. I guess the adage, "You get what you pay for" is very much in play with these tubes.

[rpf]

I've used JJ 12AU7s and 12AX7s in my Rogue Cronus Magnum for several months without problems. They sound better than any of the other new productions tubes that I've tried (most, including Genalex, Psvane, Tung-Sol, Mullard, Ruby Chinese, Sovtek, EH). But long term I can't comment as to their reliability.

As good as they sound they don't come close NOS.

[steve]

The JJ E88cc tubes can be incredible, lasting up to 28,000 hours in my preamplifiers. Sound perfect as well. But there have been quality issues over the last decade.

Some years ago, there were problems with cathode poisoning, after only 4 hours, give or take. This lasted until new vacuum pumps were installed.

So there are again problems with quality? What a shame.

Cheers

[Response Audio]

I do really like the E88C JJs. I have not had the same failures with these as the 12AU7s. I haave had only 2 noisy tubes out of countless pieces i have brought in.
i am going to give these the benefit of the doubt for now as I really like the sound. This is the tube we supply in our Music Bella Segue tube buffer and dont recomment to my customers to change them out u til they have had a chance to burn them in and hear what they are capable of.

I just swapped in some original Mullard grade A CV4003 tubes in my Purity integrated hybrid amp. Very nice tube. I may try a pair of old 7136 tubes I have and see how they sound when i have some time.

[steve]

I just got a pair of new production Telefunken E88cc tubes in. Running them for two days now.

Bass has better control than JJ brand, mid and highs are more open, natural.

Noise, what noise, so good for phono stages. Beats Genalex hands down, which has zingy highs, and looser bass.

Less expensive as well.
Beats the Bugleboys (got 2 dozen of them, Qs)

The tube just "sounds" a little more realistic, that last bit of realism.

This tube "sounds" near perfect, if not perfect.
If it lasts like the JJs do, approx. 26,000 hours.

This is one heck of a tube.

Cheers

[richidoo]

Nice info Steve, thanks. They are made by JJ, but tested by Tele and cryoed. Lots of different types available including power tubes.

[mfsoa]

Hi Steve,

Thanks for the input.  I just retubed a pre with some inexpensive EH 6922s because I had no idea how old the previous tubes were.

Can you compare the new Teles to the EH 6922s?

I know I know, different systems respond differently-

But whaddya say?

Thanks

[steve]

Hi Steve,

Thanks for the input.  I just retubed a pre with some inexpensive EH 6922s because I had no idea how old the previous tubes were.

Can you compare the new Teles to the EH 6922s?

I know I know, different systems respond differently-

But whaddya say?

Thanks

Hi MFSOA,

I do not have any EH E88cc tubes. Been years, decades ago.

I could only compare EH to JJ KT-88s. The EH sound much fuller than the JJ KT88s. Almost like the EH lack highs. But I would not bank on the comparison being valid to the signal tubes.

Cheers, and great week.

[rollo]

Hey Steve good info here thanks. Was curious about the new Tele.


charles