5692, the best?

[Makofoed-6sn7]

Hello folks,

I just got two large box's full of tubes. A lot of nice stuff in them, but two tubes got my eyes up. They are named 5692, they got my atention becouse they have a red base. I think I heard something about they were "The one and only".
Does any one have any experience with those tubes?


Best regards,

Magnus

 

[SY]

I did a bunch of 5692 measurements. Search the forum for a thread with a title like "SY gets jiggy."

 

[Tubelab_com]

I have a fairly wide assortment of 6SN7 tubes, mostly used military surplus tubes, but about 20 NOS specimens of various brands. A few years ago I built a line stage that used a 6SN7. I tried about 50 different tubes in it, and came to the (possibly mistaken based on the source of the tubes) conclusion that "all 6SN7's are microphonic". I have a Motorola branded tube that is so bad that you can actually use it as a microphone and your (hollow sounding) voice comes out of the speakers. The line stage went into the closet, and I built another one with 5842's.

While digging in some unexplored boxes full of tubes in my warehouse, I found a bag with 4 dirty red based 5692's in it. I plugged them into the line stage, and there are ZERO microphonics. All you hear is a dull thud when you whack one with a pencil. At least in this regard they are better. You can see this by looking at the construction of the mica spacers.

 

[Rocky]

Magnus,

Har et matchet par RCA 5692 som testet 100% da jeg kjøpte dem for lenge siden. Tre lag glimmer, masse støttepinner, tykt glass, rød base. Har aldri trengt dem, da jeg begynte med direktevarmet katode rør istedet - så om du har lyst på dem til backups kan du få dem billig. De kommer nok til å ligge i skapet i overskuelig framtid så bare si ifra om du skulle trenge dem.

 

[Makofoed-6sn7]

Thanks to SY and Tubelab for useful info.
I'll think I will like those tubes. My linestage and poweramplifier uses 6SN7. I will try 5692 later today.

Best regards,

Magnus

Rocky,

Jeg kunne veldig gjerne tenkt meg et par som backups siden det virker som disse rørene er gode. Du kan kontakte meg på Magnus at Kofoed.no

 

[Miles Prower]

While digging in some unexplored boxes full of tubes in my warehouse, I found a bag with 4 dirty red based 5692's in it. I plugged them into the line stage, and there are ZERO microphonics. All you hear is a dull thud when you whack one with a pencil. At least in this regard they are better. You can see this by looking at the construction of the mica spacers.

I've found that the Sovtek 6SL7s and 6SN7s aren't detectably microphonic. A sharp whack doesn't cause any disturbance to the display when o'scoping the output. A NOS Westinghouse JAN 6J5 showed a slight disturbance when similarly whacked.

 

[Makofoed-6sn7]

Hello again,

I have now tested the 5692 tubes.
It was really nice. Absoultely no sign om microphonics. Not even when wack'd with a little skrewdriver(My normal test standard, if they short's out they are bad anyway, but don't do it with DH tubes). Dead silence I love it.
Aparently they arn't just a hype.

Best regards,

Magnus

 

[anatech]

Hi Miles,
Electroharmonix are the same, they sound a little better in my experience.

-Chris

 

[Makofoed-6sn7]

I bought some Sovtek 6SL7 one time we were ordering tubes at work. I was dispointet becouse 3 of 6 valves were sensetiv to hum. With one GE 6SL7 I have, no such problem was observed.

Regards,

Magnus

 

[Miles Prower]

I bought some Sovtek 6SL7 one time we were ordering tubes at work. I was dispointet becouse 3 of 6 valves were sensetiv to hum. With one GE 6SL7 I have, no such problem was observed.

Regards,

Magnus

Since I'm using DC for heating, I wouldn't notice a problem like that anyway. May be some sort of heater leakage?

"Electroharmonix are the same, they sound a little better in my experience."

I'll keep that in mind for future reference. You referring to 6SN7s? I'm using the Sovtek 6SN7s as cathode follower drivers, so I wonder if it would make much of a difference anyway?

 

[anatech]

Hi Miles,
I did replace a set of Sovtek 6SN7's with Electroharmonix 6SN7's. It was a pleasant experience. Same with 12AX7's and especially the 6L6 types. I did use Sovtek for a while as they were they only reasonable thing that was available to me. A big improvement over the "National" brand at the time. Previously I was able to source GE and Westinghouse, some RCA when I got lucky.

Right now the Electroharmonix stuff has allowed me to relax knowing I can just order them and go.

-Chris

 

[Makofoed-6sn7]

Miles,

Might be, I always use AC on the heaters becouse it's simple. I have the filament placed on about 40v via the center tap.
So if there were som heater leakage, I don't think the tubes are good enough. They should be more well made if you ask me. Since 3 works and 3 have trouble.

I remeber that the lot of EL34 we ordered at work for about one year ago was were flimsy. The shorted out when they were tested with a light bang. But that was a one time experiense, the next lot was much better, only 1 dud tubes in about 100-200 pcs.
I might be the same for the 6SL7

 

[anatech]

Hi Makofoed-6sn7,
My experience with the earlier Sovtek was similar to yours, they did get better, but that was a long time ago. I have found that the 6CA7 does a better job than the EL34.

With 40 V bias on the heaters, you shouldn't have any hum. Leaky heater to cathode for sure.

-Chris

 

[Makofoed-6sn7]

I think every production place in world have a bad series, I never juge them to hard. They will probaly get better.

There is a small problem with 6CA7 to replace EL34.
The customers complaine! They haven't got the right tube. The sound dosen't matter, the name says it all. Does darn "expert" in the guitar biss.

Regards,

Magnus

 

[anatech]

Hi Magnus,

There is a small problem with 6CA7 to replace EL34.
The customers complaine! They haven't got the right tube.

You can't win with that.

-Chris

 

[Makofoed-6sn7]

Hi Chris,

No, you are most certanly right about that. I have had enough discussion about 12AX7 vs ECC83. In one case someone wanted ECC83 and we only had 12AX7 EH(Our standard tube "for everything") and he got mad after a while. Even when I showd him the euq. list we have.
Another time some one wanted a Philips 12AX7. I had some Philips ECC83 that I offered him. Again, the same route..

There will always be *********...

-Magnus

 

[anatech]

12AX7EH is an excellent choice.

Your customers don't know their tubes either. Take a lot of aspirine?

-Chris

 

[Makofoed-6sn7]

Yes, we found out that EH was the way to go. Before we used sovteks, but there are small differance's. EH is dead silent in almost any guitar amp, but sovtek is always more or less microphonic. Also, one time a amp had a "rumbling" sound, non of the sovteks took it, but EH did it.

I have troubles with a lot of migraine, I just found the source...

Magnus

 

[anatech]

You know,
6L6EH will survive in Fender Twins, 6CA7EH are tougher from what I've seen than the EL34's.

I have only had one microphonic 12AX7EH to date.

-Chris

 

[Makofoed-6sn7]

If there have come 6L6EH I will most certanly try it out. Last time i chek'd the catalog from Newsensor at work they had only sovtek 6L6. But, that said, sovtek 6L6 have never had troubels.

A funny thing about the twin amps. For some unknow reason people manage to knock the output tubes out the socket under transport... Even with the "jaws" that have a firm grip around the tube.

Magnus