[Jon Yaeger]

How much should the skinny Sovtek/Reflector EL34s be derated in terms of
idle current and maximum wattage (vs. Mullard, for example)?

TIA,

Jon

[Patrick Turner]

Jon Yaeger wrote:

How much should the skinny Sovtek/Reflector EL34s be derated in terms of
idle current and maximum wattage (vs. Mullard, for example)?

TIA,

Jon

The "slimline" design of Sovtek EL34 is the same as the original
EL34 made years ago despite the glass envelope being slimmer
than the original.
28 watts is the total figure for anode and g2.

But only an idiot would ever run them at the data rating,
and most EL34 are better run at no more than 23 watts for safety.
6CA7 with their larger anodes can take the full 28 watts, but I never
allow it.
28 watts is the design figure up to where you'd wanna run the tubes;
there is a dashed line on the data ra curves which assist in determining
a load value that does not
ever cross the Pda line, but ppl set up tube amps with a gay disregard
for suchlike and don't mind the load at full power or near it causing
dissipation above the rated figures.
This does not matter much in hi-fi amps which have low average power
output
and well below clipping power. But its lethal in a guitar amp.
I don't like exceeding Pda during wave cycles because it is accompanied
by
the high distortions I like to avoid, and indicates the amount of class
A power is low,
and too low.
Seimans made a small version of EL34 perhaps in East Germany maybe,
and that could not take 28 watts without turning a little red in the
face.
But operated in low bias class AB circuits such "slimmies"
work fine, and 16 watts is a commoj figure for idle conditions.

But be a real man, use KT88/90 instead :-),

Patrick Turner.

[Sander deWaal]

Patrick Turner said:


Seimans made a small version of EL34 perhaps in East Germany maybe,
and that could not take 28 watts without turning a little red in the
face.
But operated in low bias class AB circuits such "slimmies"
work fine, and 16 watts is a commoj figure for idle conditions.


Good NOS Philips EL34 will withstand enormous abuse.
25 watts PD and a lifetime of 4 years ;-)


But be a real man, use KT88/90 instead :-),


In triode, agreed.
2A3 PP sounds nicer, though (sorry, I don't do monster tube amps like
your 12 cylinder 300 HP beastie, Patrick).


--
- Ever seen someone with 5.1 ears? So, what does that tell you? -

[Patrick Turner]

Sander deWaal wrote:

Patrick Turner said:

Seimans made a small version of EL34 perhaps in East Germany maybe,
and that could not take 28 watts without turning a little red in the
face.
But operated in low bias class AB circuits such "slimmies"
work fine, and 16 watts is a commoj figure for idle conditions.

Good NOS Philips EL34 will withstand enormous abuse.
25 watts PD and a lifetime of 4 years ;-)

Gee, abusing NOS EL34 is like buying a NOS Spitfire to fight the
terrorists.
( people who disagree with us ).

Nevertheless, I have had a second hand EL34 in SET in a radio I have
used daily
for 3 hrs at least over the last 7 years.
But it hasn't been abused, it just sits there turned on,
and only has to convert a small portion of its class A Pda of about 20
watts
into an average of 0.1W most days.

But in a guitar amp, I don't think NOS EL34 would last very well
with constant overload.



But be a real man, use KT88/90 instead :-),

In triode, agreed.
2A3 PP sounds nicer, though (sorry, I don't do monster tube amps like
your 12 cylinder 300 HP beastie, Patrick).

Its almost impossible to make a bad sounding triode amp....

The 300 HP jobbies are gentle giants and exude a sense of
effortlessness, but still have the creaminess and detail of a decent
tube amp.


--
- Ever seen someone with 5.1 ears? So, what does that tell you? -

5.1c brain value.

Patrick Turner.