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michael Mueller
July 26th 03, 10:51 PM
Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
few with ceramic bases. Big question though, I also bought an 811. Why"
, because it was nos, in military box , looked really cool etc etc etc,.
Doe any one have a schematic for an amp with this tube.
Thanks
Mike M

Gregg
July 26th 03, 11:05 PM
Behold, michael Mueller scribbled:

> Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
> few with ceramic bases.

Go get 'em Fred :-D

--
Gregg
*It's probably useful, even if it can't be SPICE'd*

BEAR
July 27th 03, 12:01 AM
FYI,

4 x 807 in AB2 set up right will do 200 watts...

_-_-bear

michael Mueller wrote:

> Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
> few with ceramic bases. Big question though, I also bought an 811. Why"
> , because it was nos, in military box , looked really cool etc etc etc,.
> Doe any one have a schematic for an amp with this tube.
> Thanks
> Mike M

michael Mueller
July 27th 03, 04:15 PM
Thank you Bear. That I know. What I wanted to know was if any one had a
schematic that would use the 811. SE would be fun to try.
Thanks again
Mike M

Jim Candela
July 27th 03, 11:20 PM
Mike,

The 811 has a very high amplification factor, and was designed for Class
B operation with no bias, or just a little bias at maximum plate voltage
(i.e. -4.5 volts bias @ 1500 volts plate). For this reason the 811 is a poor
choice as a single ended class A audio amplifier. The brother to the 811 is
the 812, and this dude is more suitable for what you are wanting to do
because the amplification factor is much lower.

It would be interesting though to play with that 811, and with a
suitable driver circuit, you could definitely make a lot of noise. Now
running grid current for 1/2 the audio waveform will require a very low
impedance driver. It remains to be seen if you can get low distortion out of
such a setup even when resorting to that dirty word for SE triode amps:
negative "feedback".

Sell that 811 to a ham operator, and look for a low to medium mu triode
instead.

Regards,
Jim


"michael Mueller" > wrote in message
thlink.net...
> Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
> few with ceramic bases. Big question though, I also bought an 811. Why"
> , because it was nos, in military box , looked really cool etc etc etc,.
> Doe any one have a schematic for an amp with this tube.
> Thanks
> Mike M
>
>

Adam Stouffer
July 29th 03, 04:27 AM
michael Mueller wrote:
> Thank you Bear. That I know. What I wanted to know was if any one had a
> schematic that would use the 811. SE would be fun to try.
> Thanks again
> Mike M
>


http://24.53.190.127:808/~tesla/811a_single_12ay7.jpg

I used a 12AT7 and 6L6 instead and got excellent results. Heres my
progress so far:

http://24.53.190.127:808/~tesla/amplifier.jpg

If the site doesn't work try again later, my cable modem has some
serious issues.


Adam

Ross Matheson
July 29th 03, 08:57 AM
Adam Stouffer > wrote:

: I used a 12AT7 and 6L6 instead and got excellent results. Heres my
: progress so far:
:
: http://24.53.190.127:808/~tesla/amplifier.jpg

Are they standard banana plugs on the anode leads? Safety?
Good idea for metering, I suppose (but maybe not "childproof":-)

How is the "brushed" look achieved, or is it just a trick of reflection?
Is it just an orbital sanding effect? The reflections of circular objects
seem magnified, giving it an almost circular sanding effect there.

This reminds me of deep "holographic" effects I've seen deliberately created
on "art" metal furniture, at an interior design show. Might be neat to do...
I've read since that "3D effects are intentionally produced on steel
surfaces through use of a wire-brush power tool. The larger the diameter of
the brush, the deeper will be the apparent highlights."

That reminds me of earlier reading this page, just as a general overview
http://www.amasci.com/amateur/holo1.html
and, from a link off it, a remark on the abrasive effect, at the bottom of
http://www.rgmwatches.com/engine.html
As an aside, have a look at the amazing patterns here:-) Chassis decor?
http://www.rgmwatches.com/engine99.html
Too hard over large surfaces though, I bet, but quite extraordinary.
[Doesn't affect the sound, anyway, either!]

Regards, RdM

Adam Stouffer
July 29th 03, 10:45 PM
Ross Matheson wrote:

> Are they standard banana plugs on the anode leads? Safety?
> Good idea for metering, I suppose (but maybe not "childproof":-)

Yeah they plug into the red binding posts. Not entirely childproof but
theres no children here anyhow. You would have to try really hard to
touch anything exposed.

> How is the "brushed" look achieved, or is it just a trick of reflection?
> Is it just an orbital sanding effect? The reflections of circular objects
> seem magnified, giving it an almost circular sanding effect there.

Its just the reflection, the chassis is an aluminum street sign I had
machined. Thats the top side which used to be bare. All I used was a
coat of primer and two coats of spray paint. I thought the red paint
would be more a rust color but turned out to be fire engine. The bigger
choke is gun metal blue touch up paint for a Chevy Caprice. Hey it was
just sitting there and not being used :)

Adam

michael Mueller
July 29th 03, 11:04 PM
Thankyou Jim.
I had 4 schematics forwarded to me. Since I bought it, I have to try it.
I'll post information ans pics as I proceed.
Thanks again
Mike M

Philip Lawrence
July 31st 03, 01:02 PM
michael Mueller wrote:
> Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
> few with ceramic bases. Big question though, I also bought an 811. Why"
> , because it was nos, in military box , looked really cool etc etc etc,.
> Doe any one have a schematic for an amp with this tube.
> Thanks
> Mike M
>
>
HiMike
I have circuits for 811A SE and PP.
They are much better PP {My opinion Any way.}
PP gives over 100 watts with only 580volts at 70Ma
Phil