Gentlemen,

here you can find plate curves for triode strapped pentode
section of ECL82/6MB8/PCL82/16A8, which might be of interest
to you:

http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

Data was derived and averaged from three NOS/NIB ECL82/PCL82
samples from manufacturers Polam, Valvo and Siemens, which
performed very uniform.

The trioded pentode section of ECL82 could be viewed as four
paralleled sections of 6SN7, except for the considerably lower
mu of ca. 7.

This and the fair linearity suggest usage as a beefy low voltage
gain, low Zo gnd'ed cathode "power"-driver, and that's how it is
used in my current amp project.

Regards,

Tom

--
Do not meddle in the affairs of wizards,
for you are crunchy and good with ketchup.

Nice one Tom !!

Did you do it all by hand ??

Ronald .


"Tom Schlangen" schreef in bericht
...
Gentlemen,

here you can find plate curves for triode strapped pentode
section of ECL82/6MB8/PCL82/16A8, which might be of interest
to you:


http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

Data was derived and averaged from three NOS/NIB ECL82/PCL82
samples from manufacturers Polam, Valvo and Siemens, which
performed very uniform.

The trioded pentode section of ECL82 could be viewed as four
paralleled sections of 6SN7, except for the considerably lower
mu of ca. 7.

This and the fair linearity suggest usage as a beefy low voltage
gain, low Zo gnd'ed cathode "power"-driver, and that's how it is
used in my current amp project.

Regards,

Tom

--
Do not meddle in the affairs of wizards,
for you are crunchy and good with ketchup.

Tom Schlangen wrote:
Gentlemen,

here you can find plate curves for triode strapped pentode
section of ECL82/6MB8/PCL82/16A8, which might be of interest
to you:


http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

What do the numbers 0, -2, -4 ... -32 represent on each curve?


The trioded pentode section of ECL82 could be viewed as four
paralleled sections of 6SN7, except for the considerably lower
mu of ca. 7.

You mean the triode-WIRED pentode section?

This and the fair linearity suggest usage as a beefy low voltage
gain, low Zo gnd'ed cathode "power"-driver, and that's how it is
used in my current amp project.

Regards,

Tom

--
Do not meddle in the affairs of wizards,
for you are crunchy and good with ketchup.

Hi Ronald,

Did you do it all by hand ??

Yes, but Ines helped keying in the data while I juggled
the PSU controls and read out the DVMs. Ea stepped 5 volts,
-Eg1 stepped 2 volts, to be multiplied by 3 sample tubes.

After human action-synchronizing, data collection was
done within 2 hours. Maybe 1/2 an hour of graph formatting
was needed.

It was worth the effort, I think, since data of trioded
mode of the pentode section of this unexpensive and high
obtanium state tube is extremely scarce. And the only other
plate curve plot I know of is so much off my own readings,
that I doubt the same tube was used ...

ECL82 is a very versatile tube and it was (mis?)used
in almost any imaginable tube app, from RF oscillators
and small RF transmitters over TV deflection circuits
over small stabilized pass type PSUs over small audio
SE and PP amps of any kind.

It has a somewhat "bad name" among audiophools because
it was propagated for many extremely simple and small
"starter"-level SE amps (yeah, I used it in my own first
truly DIY small power amp, too) and all the el cheapo
micro-iron TV and radio set SE output stages it was used
in, but one has to blame the bean counters cutting quality
of the environment ECL82 had to work in instead of blaming
the tube itself, I think.

Besides usage as a beefy SE driver, here are some other
ideas:

- Two ECL82 w/ trioded pentode sections can make a complete
Williamson style gain/splitter/driver front end (the lowish
optimum plate voltage of the triode section comes in handy
for DC coupling between voltage gain and concertina stage)

- they also could be used in a Mullard style PP amp frontend,
using the small signal triodes SRPP'ed (the highish allowed
heater-cathode voltage comes in handy, no separate heater
circuit needed) and the trioded pentode sections used as
a "power LTP" (like Patrick drives his multi-6550-PP
monsters by a power LTP made of trioded EL84/6BQ5).

A noteworthy restriction for either SE or PP amp front ends
using ECL82 is the lowish combined/total voltage gain of both
sections: maybe 100-150 times for two consecutive gnd'ed
cathode stages to drive an SE output stage and for the
Williamson style PP front end, and maybe 300 times for
a SRPP/LTP PP front end.

But in situations where not much gNFB is needed (say, with
triode output stages or tetrode mode w/ CFB, hehe ;-) I am
eager to see a tube that does the voltage gain and driver
job better and more efficient than this single girlie noval
envelope ECL82 compound tube :-)

Tom

--
Live is too short to be taken seriously.
- Oscar Wilde

Hi kseely,

What do the numbers 0, -2, -4 ... -32 represent on each
curve?

Grid (g1) voltage.

The trioded pentode section of ECL82 could be
viewed as four paralleled sections of 6SN7,
except for the considerably lower mu of ca. 7.

You mean the triode-WIRED pentode section?

Yes.

Tom

--
Falling in love is a lot like dying.
You never get to do it enough to
become good at it.

This is a real contribution to our NG, thanks mr. Schlangen!
The 6BM8 is a good and cheap tube, and I was planning to use it in the
future as a driver for a 300B or an 811/10 SE, just like You said (I have a
couple of TFK still wrapped in cellophane and I did not even pay a fortune
for them..).

Ciao

Fabio

"Tom Schlangen" ha scritto nel messaggio
...
Gentlemen,

here you can find plate curves for triode strapped pentode
section of ECL82/6MB8/PCL82/16A8, which might be of interest
to you:


http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

Data was derived and averaged from three NOS/NIB ECL82/PCL82
samples from manufacturers Polam, Valvo and Siemens, which
performed very uniform.

The trioded pentode section of ECL82 could be viewed as four
paralleled sections of 6SN7, except for the considerably lower
mu of ca. 7.

This and the fair linearity suggest usage as a beefy low voltage
gain, low Zo gnd'ed cathode "power"-driver, and that's how it is
used in my current amp project.

Regards,

Tom

--
Do not meddle in the affairs of wizards,
for you are crunchy and good with ketchup.

"Tom Schlangen" wrote in message
...
Hi Ronald,

Did you do it all by hand ??

Yes, but Ines helped keying in the data while I juggled
the PSU controls and read out the DVMs. Ea stepped 5 volts,
-Eg1 stepped 2 volts, to be multiplied by 3 sample tubes.

After human action-synchronizing, data collection was
done within 2 hours. Maybe 1/2 an hour of graph formatting
was needed.

It was worth the effort, I think, since data of trioded
mode of the pentode section of this unexpensive and high
obtanium state tube is extremely scarce. And the only other
plate curve plot I know of is so much off my own readings,
that I doubt the same tube was used ...

ECL82 is a very versatile tube and it was (mis?)used
in almost any imaginable tube app, from RF oscillators
and small RF transmitters over TV deflection circuits
over small stabilized pass type PSUs over small audio
SE and PP amps of any kind.

It has a somewhat "bad name" among audiophools because
it was propagated for many extremely simple and small
"starter"-level SE amps (yeah, I used it in my own first
truly DIY small power amp, too) and all the el cheapo
micro-iron TV and radio set SE output stages it was used
in, but one has to blame the bean counters cutting quality
of the environment ECL82 had to work in instead of blaming
the tube itself, I think.

Besides usage as a beefy SE driver, here are some other
ideas:

- Two ECL82 w/ trioded pentode sections can make a complete
Williamson style gain/splitter/driver front end (the lowish
optimum plate voltage of the triode section comes in handy
for DC coupling between voltage gain and concertina stage)

- they also could be used in a Mullard style PP amp frontend,
using the small signal triodes SRPP'ed (the highish allowed
heater-cathode voltage comes in handy, no separate heater
circuit needed) and the trioded pentode sections used as
a "power LTP" (like Patrick drives his multi-6550-PP
monsters by a power LTP made of trioded EL84/6BQ5).

A noteworthy restriction for either SE or PP amp front ends
using ECL82 is the lowish combined/total voltage gain of both
sections: maybe 100-150 times for two consecutive gnd'ed
cathode stages to drive an SE output stage and for the
Williamson style PP front end, and maybe 300 times for
a SRPP/LTP PP front end.

But in situations where not much gNFB is needed (say, with
triode output stages or tetrode mode w/ CFB, hehe ;-) I am
eager to see a tube that does the voltage gain and driver
job better and more efficient than this single girlie noval
envelope ECL82 compound tube :-)

Tom

--
Live is too short to be taken seriously.
- Oscar Wilde


Also an excellent candidate for a Kimmel Mu stage in one tube.

Doug

Hi Doug ,

Also an excellent candidate for a Kimmel Mu stage in one tube.

Why would you ...... It takes all the fun out of the mu-stage .
Svetlana did that already with absurd high voltages so it isn't much
of a challenge anymore .
And if you use seperate tubes for triode and pentode you could
very easy swap triodes in a mu-stage . That's part of the big fun !!
I didn't try the ECL82 pentode (yet ?) in a mu-stage , but on paper
it's on the edge of usable / not usable for a good mu-stage .
S (gm) is just 9mA/V IIRC with 10mA/V as my "rule of thumb" minimum .

Just my 0.02 ,

Ronald .

Hi Fabio,

This is a real contribution to our NG, thanks mr. Schlangen!

I glad that I can give a little bit back.

I was planning to use it in the future as a driver for a 300B
or an 811/10 SE

I don't know about 811 drive requirements, but driving a 300B
should be no problem for the trioded pentode section of ECL82.
For a start, I would try something like B+ = 300V, Ra = 8k2 or
10k and Ia = 20mA.

I have a couple of TFK still wrapped in cellophane and I did
not even pay a fortune for them..).

Yeah, and PCL82 is even cheaper ... recently I got a few dozen
mil stock '80s production Siemens for less than an Euro per piece
via Ebay ... invest a few cents in a LM317T based 300mA CSS for
the heaters and forget about heater-induced hum.

You surely know about the Italian "Lo Scherzo" ECL82 application
series? Considering your 300B project, have a look at the
choke - errr - OPT loaded "driver" variant, too.

Tom

--
The first rule of magick is simple: Don't waste your time
waving your hands and hoping, when a rock or club will do.

Please download:

http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

again for slightly corrected mu, gm and rp values.

Tom

--
If in doubt, mumble.