Sovtek's "5881." A 40W tube?

[Nigel]

I've heard the stories that this Russian MiG/Submarine/ICBM tube of DEATH can dissipate 42 watts before red plating.

It comes stock in Soldano's, Zinky's (I have a MOFO) and has been OEM for MANY other brands, usually to the chagrin of it's owner. They've been called bland, sterile, cardboard, icepick, etc.

So, I biased some up to 25w at idle tonight, and man they sound GREAT~!

If they really are a 40 watt tube, NO WONDER THEY SOUND LIKE DOG SHYTE when biased like a 6L6!

25w of a 40w tube is only 62.5%! That's barely warm! Anyone else have a similar experience?

 

[guitarslinger]

Kind of like the JJ6V6, which isn't really a 6V6, but some military tube that works in 6V6 applications. Jj 6V6's can be biased extremely hot and run at high voltages that would fry any other 6V6 type tube.

JJ6V6 is LOUD as hell. Love those tubes.

 

[Nigel]

Has anyone here done tests? The consensus has been they suck, period, end of story.

I had moved to JJ 6L6's personally.

However, these biased hot are staying.

 

[killertone]

Haven't used them in a while but never had a single problem with them in the past. Had them in my Marshall 9200 for a couple years and they sounded just fine. I will say this, the failure rate on them is very low, at least in my experience.

 

[RoccaforteAmps]

I've heard the stories that this Russian MiG/Submarine/ICBM tube of DEATH can dissipate 42 watts before red plating.

It comes stock in Soldano's, Zinky's (I have a MOFO) and has been OEM for MANY other brands, usually to the chagrin of it's owner. They've been called bland, sterile, cardboard, icepick, etc.

So, I biased some up to 25w at idle tonight, and man they sound GREAT~!

If they really are a 40 watt tube, NO WONDER THEY SOUND LIKE DOG SHYTE when biased like a 6L6!

25w of a 40w tube is only 62.5%! That's barely warm! Anyone else have a similar experience?

That 40watt rating is not for audio........
Bias just like you would any 6L6 type.

 

[RoccaforteAmps]

Kind of like the JJ6V6, which isn't really a 6V6, but some military tube that works in 6V6 applications. Jj 6V6's can be biased extremely hot and run at high voltages that would fry any other 6V6 type tube.

JJ6V6 is LOUD as hell. Love those tubes.

depending on the circuit they're in......
It's actually more a 7591 than 6V6.
fwiw

 

[Nigel]

That 40watt rating is not for audio........
Bias just like you would any 6L6 type.

Then what is it? How is it not 40w for audio?

The tube doesn't sound musically non-resistive until dissipating 25+ watts.

Thanks for chiming in Doug!

 

[RoccaforteAmps]

That 40watt rating is not for audio........
Bias just like you would any 6L6 type.

Then what is it? How is it not 40w for audio?

The tube doesn't sound musically non-resistive until dissipating 25+ watts.

Thanks for chiming in Doug!

I'm only guessing why someone would say 40,
but if someone is saying 40watts I would suspect under different conditions than an audio circuit.
How I know it's not for audio, I've worked with these tubes for many
years, and have never seen a pair produce 80watts in any audio
circuit (guitar or hifi), and if they could we would see many.

These sound the best ran over 500V, thats when they really come alive .
Currently, they're still the most bulletproof tube made today.
I use them. Doug

 

[Nigel]

I've got a Zinky Mofo and they are at about 550 +/- 3v or so.

They start being fun around 550v, 42ma or 23w, and get to be real fun 46-47ma or 25-26w.

I've read reports of people running them at 40w with no red plating (500v@80ma), and consistently for a year at 35w.

They aren't as loud as the JJ 6L6GC, but man they sound killer hot and high voltage.

 

[RoccaforteAmps]

I've got a Zinky Mofo and they are at about 550 +/- 3v or so.

They start being fun around 550v, 42ma or 23w, and get to be real fun 46-47ma or 25-26w.

I've read reports of people running them at 40w with no red plating (500v@80ma), and consistently for a year at 35w.

They aren't as loud as the JJ 6L6GC, but man they sound killer hot and high voltage.

You do understand that biasing for 40watts doesn't
mean you're going to get 40watts of power output.

 

[Nigel]

Ok. I've got 3 pair to test tonight. Will post results. Unfortunately, one cannot measure audio output with a bias rite, correct? Only dissipation? I've noticed these are lower output than the JJ's.

 

[Nigel]

Had one red plate at 50ma.

Sticking with two that do about 44-46ma @ 545v.

Warm enough to crank the clean volume up and get sweet saturation, not to hot to flub under high gain/high volume conditions.

BALANCE FTW.