[North Lake Audio]

Total of five for auction in Dutch auction, beginning at $7.95 per tube.

http://cgi.ebay.com/ws/eBayISAPI.dll...6328&ssPa geN
ame=STRK:MESE:IT&ih=005

Thanks,
Steve

[[email protected]]

North Lake Audio wrote:
Total of five for auction in Dutch auction, beginning at $7.95 per tube.

While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors. Won't affect the calibration, will take the
filament load off the transformer, and will reduce heat inside the
unit. Given that most of these tubes are also mounted sideways and are
designed for "base down", this is one more reason to sub the diode
system.


Peter Wieck
Wyncote, PA

[Ned Carlson]

wrote:
North Lake Audio wrote:
Total of five for auction in Dutch auction, beginning at $7.95 per tube.

While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors.

A couple of 10 volt, 1 watt zener diodes would be better.
The point of using the 83 gas rectifier is that the voltage drop
is nearly constant, independent of current draw.


--
Ned Carlson
SW side of Chicago, USA
www.tubezone.net

[Sander deWaal]

Ned Carlson said:


wrote:

While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors.


A couple of 10 volt, 1 watt zener diodes would be better.
The point of using the 83 gas rectifier is that the voltage drop
is nearly constant, independent of current draw.


On top of that, 2N4007 is a 20V, 0.1A PNP transistor that is likely
not to survive being forced to act as a HV rectifier evil grin

--
"All amps sound alike, but some sound more alike than others".

[[email protected]]

Sander deWaal wrote:
Ned Carlson said:


wrote:

While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors.


A couple of 10 volt, 1 watt zener diodes would be better.
The point of using the 83 gas rectifier is that the voltage drop
is nearly constant, independent of current draw.


On top of that, 2N4007 is a 20V, 0.1A PNP transistor that is likely
not to survive being forced to act as a HV rectifier evil grin

--
"All amps sound alike, but some sound more alike than others".

Sorry about that... fumble-fingers. 1N4007......

Really.

Peter Wieck
Wyncote, PA

BTW, zeners would alter the calibration. Not the end of the world, but
not a drop-in either.

[Sander deWaal]

" said:


While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors.


A couple of 10 volt, 1 watt zener diodes would be better.
The point of using the 83 gas rectifier is that the voltage drop
is nearly constant, independent of current draw.


On top of that, 2N4007 is a 20V, 0.1A PNP transistor that is likely
not to survive being forced to act as a HV rectifier evil grin


Sorry about that... fumble-fingers. 1N4007......

Really.


I knew that, I was just being sarcastic ;-)

The 1N4007 is *the* diode of choice in 50 Hz HV applications all over
the world.

Though I tend to make use of other types, like 1N5408 or Hexfred
diodes in case of large electrolytics, with small series resistors and
snubbers.

Anyway, merc vapor rectifiers are noisy, I wouldn't want one in my
amps.........

--
"All amps sound alike, but some sound more alike than others".

[Superhet]

Not so, it does affect calibration. Do tests with several types of tubes
and you will see. Use a new 83 for your tests. It can be compensated for
in the line adjust setting.

wrote:
North Lake Audio wrote:
Total of five for auction in Dutch auction, beginning at $7.95 per tube.

While nice to have authentic mercury rectifier tubes, a permanent
substitution may be made with a 4-pin base, two 2N4007 diodes and two
10 ohm @ 1 watt resistors. Won't affect the calibration, will take the
filament load off the transformer, and will reduce heat inside the
unit. Given that most of these tubes are also mounted sideways and are
designed for "base down", this is one more reason to sub the diode
system.


Peter Wieck
Wyncote, PA