Will a Shiva fry a pair of Siemens EL 34s?

[Shemp]

I have a couple of pair hanging around and I thought about popping a set in, but then I remembered someone once commenting that the Siemens were a tad sensitive to high plate voltages. How about an old set of Mullards?

[Hipster Dofus]

I am no exspert, but I belive the Siemens to like a Lower Voltage. My Shiva has 500+ V on the Plates.

[tonedaddy]

It's a little strange based on what Bogner's own manual says.

From the Shiva manual:
http://www.bogneramplification.com/ShivaManual.htm


"3. Tubes

EL34's should be only Svetlana or old stock Siemens/Telefunken/Mullard. Other brands may work but it's risky because of the high plate voltage we use."


My understanding of the Siemens is that they shouldn't be used in amps with plate voltage over 450 volts. If the Shiva is higher than 450, I'd avoid the Siemens regardless of what the Bogner manual says.

[gizmo]

I bought a few Siemens el-34s from mike @ KCA a few months ago for a Marshall and he cautioned me about high plate voltages with these. There must be something to it as Mike is generally well-regarded for his tube knowledge and advice.

[SQUAREHEAD]

When Reinhold forst started production of the Xtcy, he ALWAYS used Siemens 34's... for the first few years, until he could no longer get a good supply. They all (Ecstacys) run around the 500 mark. I've always used them in my Xtcy's and NEVER once had any problems.


:confused:

[Ed DeGenaro]

Originally posted by SQUAREHEAD
When Reinhold forst started production of the Xtcy, he ALWAYS used Siemens 34's... for the first few years, until he could no longer get a good supply. They all (Ecstacys) run around the 500 mark. I've always used them in my Xtcy's and NEVER once had any problems.


:confused:
I was gonna say i still use some Siemens 34s in my Plexi I pulled out of my old 100B.

[SQUAREHEAD]

Originally posted by Ed DeGenaro
I was gonna say i still use some Siemens 34s in my Plexi I pulled out of my old 100B.

Yep!!
Great tubes, Ed!!
I've never had one die in 20 years of using them in about everything I've ever owned.
keith

[Ed DeGenaro]

Originally posted by SQUAREHEAD
Yep!!
Great tubes, Ed!!
I've never had one die in 20 years of using them in about everything I've ever owned.
keith
I love 'em. Sheet...the ones in my plexi have been in that amp since about 5 years...and had already been in the 100B 2 years prior. :)

[ericb]

Originally posted by Ed DeGenaro
I was gonna say i still use some Siemens 34s in my Plexi I pulled out of my old 100B.

Yep I"ve used Siemens in my Orange or120 head that runs about 500volts and never had a problem despite all the warnings I got!!

eRIC

[SQUAREHEAD]

Originally posted by ericb
Yep I"ve used Siemens in my Orange or120 head that runs about 500volts and never had a problem despite all the warnings I got!!

eRIC

What's with all the warnings anyway?
They seem fine in any amp I've ever used them in... :confused:

[tonedaddy]

My understanding comes from Mike at KCA, and I assumed he was referring to RFT/Siemens.

[Blue Strat]

Originally posted by SQUAREHEAD
What's with all the warnings anyway?
They seem fine in any amp I've ever used them in... :confused:

I'm assuming that you haven't tried more than a handful of these tubes in your various amps. It's always possible to get lucky. Some tubes will beat the odds.

Even if only 10 to 20% (which would be optimistic) would fail in amps with plate voltage over 450V, it would be pretty lame to recommend them for such applications knowing this fact.

[Shemp]

Originally posted by Blue Strat
I'm assuming that you haven't tried more than a handful of these tubes in your various amps. It's always possible to get lucky. Some tubes will beat the odds.

Even if only 10 to 20% (which would be optimistic) would fail in amps with plate voltage over 450V, it would be pretty lame to recommend them for such applications knowing this fact.

Hi Mike

Thanks for the reply. What do you recommend for the EL 34 Shiva?

[Blue Strat]

Originally posted by Shemp
Hi Mike

Thanks for the reply. What do you recommend for the EL 34 Shiva?

SEDs, GT 6CA7GEs or Mullards (which are VERY pricey).

[hipfan]

Originally posted by Blue Strat
SEDs, GT 6CA7GEs or Mullards (which are VERY pricey).

Mike - Speaking of the GT 6CA7GE's, I was wondering if you had any observations on properly biasing these tubes. Some resources I've seen say that they should be treated as EL34's for biasing purposes. Groove Tubes, however, (or at least Myles) says that they should be biased more like 6L6's or in between 6L6's and 6550's. This would result in a significantly warmer bias setting, if I'm doing the math correctly.

I have a Rivera Fandango that I'm using them with, and it runs about 455 volts usually, for reference. Thanks for any insight!

[SQUAREHEAD]

Originally posted by Blue Strat
I'm assuming that you haven't tried more than a handful of these tubes in your various amps. It's always possible to get lucky. Some tubes will beat the odds.

Even if only 10 to 20% (which would be optimistic) would fail in amps with plate voltage over 450V, it would be pretty lame to recommend them for such applications knowing this fact.

Well...I guess I've been quite lucky. I have owned 5 Bogners in the last 14 years and every Marshall 100 watter I've owned/own has Siemens 34's in it, some of them are real old amps with plate voltage pushing 550...
NEVER once have I EVER had one problem!

Keith:)

[SQUAREHEAD]

Originally posted by Blue Strat
I'm assuming that you haven't tried more than a handful of these tubes in your various amps. It's always possible to get lucky. Some tubes will beat the odds.

Even if only 10 to 20% (which would be optimistic) would fail in amps with plate voltage over 450V, it would be pretty lame to recommend them for such applications knowing this fact.

Hey Mike,

Why would Reinhold use that tube in all his amps if they were not safe over the 450 mark? (most Bogners are around 500)
I do believe this "450" thing, not at all that I doubt you, as I've read it in many places... I just wonder why he would do that?

Take care,
Keith

[Mark Kane]

I've seen Seimens run forever at real high voltages and I've also seen three of them blow within a couple minutes at around 500 volts from personal experience. If they are gonna go they will go pretty quick. Bogner may be running 150k bias resistors between the PI and out put tubes or may have a high value screen resistors in his amps, both of which will help. They are nice sounding tubes but Mike K. is right about them.

[SQUAREHEAD]

Originally posted by Mark Kane
I've seen Seimens run forever at real high voltages and I've also seen three of them blow within a couple minutes at around 500 volts from personal experience. If they are gonna go they will go pretty quick. Bogner may be running 150k bias resistors between the PI and out put tubes or may have a high value screen resistors in his amps, both of which will help. They are nice sounding tubes but Mike K. is right about them.

Oh I believe him, Mark.
I just don't understand why a guy like Bogner would use that specific tube (while he had a good supply) in ALL of his amps ... That's all. :confused:

keith

[psychodave]

Originally posted by ericb
Yep I"ve used Siemens in my Orange or120 head that runs about 500volts and never had a problem despite all the warnings I got!!

eRIC

I used them in my 67 plexi SB with 560+ volts on the plates. They lasted 10 years and now I have a pair (from the 10 year old quad) in my JCM800 2204. :dude

[Blue Strat]

Originally posted by SQUAREHEAD
Hey Mike,

Why would Reinhold use that tube in all his amps if they were not safe over the 450 mark? (most Bogners are around 500)
I do believe this "450" thing, not at all that I doubt you, as I've read it in many places... I just wonder why he would do that?

Take care,
Keith

No idea. Why would I resisit selling something that might work? Because I'd rather err on the side of caution. Having stuff blow up in people's amps isn't a great reputation builder if ya know what I mean;)

It's possible that he ran the screens at significantly lower voltage than other amps. This could definitely be a factor.

[SQUAREHEAD]

Originally posted by psychodave
I used them in my 67 plexi SB with 560+ volts on the plates. They lasted 10 years and now I have a pair (from the 10 year old quad) in my JCM800 2204. :dude

10 years!!! :eek: Wow!

[Blue Strat]

Originally posted by SQUAREHEAD
10 years!!! :eek: Wow!

Pretty impressive, eh? Yep figure at least 5:1 life span for NOS over new production power tubes.

[SQUAREHEAD]

Originally posted by Blue Strat
Pretty impressive, eh? Yep figure at least 5:1 life span for NOS over new production power tubes.


Really, Mike?
Is it that much of a difference?
Five to one?!!
Holy!
I thought maybe 2-1 or whatever...
They were really made "that much" better then vs now?
That's scary

[ericb]

Originally posted by SQUAREHEAD
Really, Mike?
Is it that much of a difference?
Five to one?!!
Holy!
I thought maybe 2-1 or whatever...
They were really made "that much" better then vs now?
That's scary

Keith I've had 60's tubes last even longer. My friend had over 20 years on his Twin's Power tubes using it 3 weekends a month with his band playing 6 hours a nite. The newer tubes I've owned typically suck ... NOT ALL but lots do

ERIC

[Blue Strat]

Originally posted by SQUAREHEAD
Really, Mike?
Is it that much of a difference?
Five to one?!!
Holy!
I thought maybe 2-1 or whatever...
They were really made "that much" better then vs now?
That's scary

Yeah, 5:1 is probably conservative too. I work on tons of 60s and 70s amps with original tubes that are just fine. Preamp tubes tend to last decades with no problem. Of course, there are always a few that either die early or defy the odds and last even longer.

Yes, they were made that much better "back in the day". Tubes were used in every piece of home audio equipment, military equipment, hospital-medical equipment, computers, space launch equipment, etc, etc.

Not only was the economy of scale effect in place (the market was probably a million times the size of the tube market today) but we didn't want fighter planes going down, heart monitors to stop working, etc.

Superior materials were more readillly available, the EPA wasn't hounding manufacturers about industrial bi-products (not that that would've been a bad thing), etc.

For $10 a pop retail for a "third world" preamp tube today, do you really expect perfection or longevity? Ain't gonna happen. As long as people are unwilling to spend more than this the current tubes available will never improve.

[hipfan]

Originally posted by hipfan
Mike - Speaking of the GT 6CA7GE's, I was wondering if you had any observations on properly biasing these tubes. Some resources I've seen say that they should be treated as EL34's for biasing purposes. Groove Tubes, however, (or at least Myles) says that they should be biased more like 6L6's or in between 6L6's and 6550's. This would result in a significantly warmer bias setting, if I'm doing the math correctly.

I have a Rivera Fandango that I'm using them with, and it runs about 455 volts usually, for reference. Thanks for any insight!

Mike - Sorry to pester you, but any thoughts on the above? Thanks!

[Blue Strat]

Originally posted by hipfan
Mike - Sorry to pester you, but any thoughts on the above? Thanks!

Ooops, I meant to answer that. I'd follow Myles recommendations. If all else fails, shoot for 60% of 30 watts idle power.

[hipfan]

Will do. Thanks, Mike!

['63-Strat]

I bought Siemens/RFT EL34s from Mike for my Bogner XTC Classic which definitely runs higher than 500V and have had no problems cranking the amp up and have to say I just love the tone. I got 'em on SQUAREHEAD's recommendation and have no regrets. When these do go, I'm buying more, actually maybe I should buy another set in case these become too scarce.

[Blue Strat]

Originally posted by '63-Strat
I bought Siemens/RFT EL34s from Mike for my Bogner XTC Classic which definitely runs higher than 500V and have had no problems cranking the amp up and have to say I just love the tone. I got 'em on SQUAREHEAD's recommendation and have no regrets. When these do go, I'm buying more, actually maybe I should buy another set in case these become too scarce.

Whew, glad I didn't know your intentions when you bought them;)

Don't wait too long, they're not making NOS tubes any more which means that supply has only one way to go....cost too (different direction though):p

[6AM]

Man... 500 ain't shit. My Hiwatt DR201 runs at 725! :eek:

[tonedaddy]

Originally posted by 6AM
Man... 500 ain't shit. My Hiwatt DR201 runs at 725! :eek: So are you running Siemens?

:eek: :D

[6AM]

Originally posted by tonedaddy
So are you running Siemens?

:eek: :D

Ummm... no. JJ E34L's actually. It's ran those the JJ's for a few years now with no problems.