[Dave]

Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box o'
fun. To be honest I'd rather not waste B+ voltage warming my room with the
tube rectifier, attractive though it is. Should I be considering some sort
of turn-on delay to bring up the voltage somewhat slower if I went with the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

[Multi-grid]

On Nov 7, 12:39 am, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box o'
fun. To be honest I'd rather not waste B+ voltage warming my room with the
tube rectifier, attractive though it is. Should I be considering some sort
of turn-on delay to bring up the voltage somewhat slower if I went with the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

So...if cathode stripping is real, do you think IDH rectifiers might
be getting stripped first? The DH 5U4 is going to be just about as
quick to ramp up B+ as a SS diode. How would it be safer?
cheers,
Douglas

[PeterD]

On Tue, 06 Nov 2007 22:39:13 GMT, "Dave" wrote:

Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box o'
fun. To be honest I'd rather not waste B+ voltage warming my room with the
tube rectifier, attractive though it is. Should I be considering some sort
of turn-on delay to bring up the voltage somewhat slower if I went with the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.


If you are building a tube amp, then it seems only proper to use a
tube rectifier...

But...

A delayed B+ is viable. There used to be a number of delay units that
looked like tubes for this purpose. They had a heater, a bi-metalic
strip and a set of contacts. IIRC you could get a number of different
delay times.

[Dave]

"Multi-grid" wrote in message
oups.com...
On Nov 7, 12:39 am, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

So...if cathode stripping is real, do you think IDH rectifiers might
be getting stripped first? The DH 5U4 is going to be just about as
quick to ramp up B+ as a SS diode. How would it be safer?

I dunno. That's why I asked. Is the existance/nonexistance of cathode
stripping under debate? I honestly don't know, so I asked.

Dave S.

[dre7]

Unless you are using expensive out of production tubes, I wouldn't worry
about cathode stripping. Go SS and use a thermistor or standby switch.

Andrew


Dave wrote in message
news:l26Yi.10587$h57.1967@edtnps89...
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

[Dave]

"PeterD" wrote in message
...
On Tue, 06 Nov 2007 22:39:13 GMT, "Dave" wrote:

Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.


If you are building a tube amp, then it seems only proper to use a
tube rectifier...

If, and only if, the power transformer you happen to have on your bench has
secondaries of such voltage as to accomodate the 50V lost through a toob and
still deliver an acceptable B+.....


But...

A delayed B+ is viable. There used to be a number of delay units that
looked like tubes for this purpose. They had a heater, a bi-metalic
strip and a set of contacts. IIRC you could get a number of different
delay times.

How 'bout these:

http://www.ametherm.com/Data%20Sheets/SL12%2015101.pdf

Attribute it to being born after 1965, but I'd probably be tempted to throw
in a little transistor-RC switch (or relay) to mute the audio until the amp
had stabilized... although for nostalgia's sake the big thumps of the Scott
299 at turn on when I was a kid do spark memories of happy times.

[Dave]

"dre7" wrote in message
t...
Unless you are using expensive out of production tubes, I wouldn't worry
about cathode stripping. Go SS and use a thermistor or standby switch.

Yeah that's about where I'm at with it. My outputs are EL84's, I like the
JJ's which I can get for $56 for a matched quad. Hardly gonna' kill me to
replace 'em every 10 years. But... I did find some inrush-limiting
thermistors (see my previous reply) and will probably throw one in.

[Andre Jute]

On Nov 6, 10:39 pm, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box o'
fun. To be honest I'd rather not waste B+ voltage warming my room with the
tube rectifier, attractive though it is. Should I be considering some sort
of turn-on delay to bring up the voltage somewhat slower if I went with the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

You're wasting your time, Dave. Cathode stripping is one of those old-
wives tales. If you're all that keen on tube rectification, use a
rectifier tube with a slow startup like the GZ37 (expensive) shown on
some of my circuits like the T39 KISS Amp. If you must build a delay
into a silicon-rectified supply, you could use a thermistor but the
downside is heat. Most of us just don't bother. Most of use have never
seen a cathode-stripped tube, or heard of anyone who stripped one.

As an alternative, I published in Glass Audio about ten years ago a
switching scheme that switches the filaments on before the B+ without
expensive and fragile relays. Again, it is years since I bothered...
But I can dust the drawing off and republish it if you wish.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

[Dave]

"Andre Jute" wrote in message
oups.com...
On Nov 6, 10:39 pm, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

You're wasting your time, Dave. Cathode stripping is one of those old-
wives tales. If you're all that keen on tube rectification, use a
rectifier tube with a slow startup like the GZ37 (expensive) shown on
some of my circuits like the T39 KISS Amp. If you must build a delay
into a silicon-rectified supply, you could use a thermistor but the
downside is heat. Most of us just don't bother. Most of use have never
seen a cathode-stripped tube, or heard of anyone who stripped one.

As an alternative, I published in Glass Audio about ten years ago a
switching scheme that switches the filaments on before the B+ without
expensive and fragile relays. Again, it is years since I bothered...
But I can dust the drawing off and republish it if you wish.

thanks for offering, but it doesn't sound necessary. I see that the
thermistors with appropriate ratings seem to run 110C at operating current.
As I noted above, the EL84's are cheap and plentiful and with a 2V input
signal can be driven by just about any tube to be found under the sun.

I could ramp up the voltages with a cascade of transistors with delays
controlled by RC networks but that hardly seems right on my first tube amp
;-)

I went with an EL84 PP design because I have the output transformers (I have
no SE transformers at all) and a power transformer that will work, albeit
large and ugly (rated at 500VA). Maybe I'll paint it gloss black and put it
in its' own plexiglass box bathed in blue light or something.

Dave S.

[Multi-grid]

On Nov 7, 1:26 am, "Dave" wrote:
"Multi-grid" wrote in message

oups.com...





On Nov 7, 12:39 am, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

So...if cathode stripping is real, do you think IDH rectifiers might
be getting stripped first? The DH 5U4 is going to be just about as
quick to ramp up B+ as a SS diode. How would it be safer?

I dunno. That's why I asked. Is the existance/nonexistance of cathode
stripping under debate? I honestly don't know, so I asked.

Dave S.- Hide quoted text -

- Show quoted text -

'scuse me, not my intention to be short. If this cathode stripping
thing were anything but a myth, the indirectly heated rectifiers would
see its effects first. They *ALWAYS* have voltage applied first, and
then get the cathodes warmed up. It is usually the crusty/dusty GZ34
rectifier that still tests as new in the vintge amps using it...
cheers,
Douglas

[Andre Jute]

On Nov 6, 11:30 pm, "dre7" wrote:
Unless you are using expensive out of production tubes, I wouldn't worry
about cathode stripping. Go SS and use a thermistor or standby switch.

Andrew

Course, we're all hanging in here helping Dave build a first budget
amp. There is a case for using a tube rectifier but it rests on the
sonics of the thing being superior to silicon rectification; when you
accept that a tube rectifier sounds better, then the switchon delay
available in most of the rectifier commonly recommended as good-
sounding is a bonus when you're working with expensive tubes or, as
you say out of production tubes: I don't for instance have spares of
my Svetlana SV572-10 and -3, tubes for which I have specific custom-
designed and wound iron.

Andre Jute
Perception is a skill that requires study and careful development over
along period of time. Few have it as a natural gift. -- Iain Churches

Dave wrote in message

news:l26Yi.10587$h57.1967@edtnps89...

Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

[Jon Yaeger]

in article , Multi-grid
at wrote on 11/6/07 7:46 PM:

On Nov 7, 1:26 am, "Dave" wrote:
"Multi-grid" wrote in message

oups.com...





On Nov 7, 12:39 am, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.

So...if cathode stripping is real, do you think IDH rectifiers might
be getting stripped first? The DH 5U4 is going to be just about as
quick to ramp up B+ as a SS diode. How would it be safer?

I dunno. That's why I asked. Is the existance/nonexistance of cathode
stripping under debate? I honestly don't know, so I asked.

Dave S.- Hide quoted text -

- Show quoted text -

'scuse me, not my intention to be short. If this cathode stripping
thing were anything but a myth, the indirectly heated rectifiers would
see its effects first. They *ALWAYS* have voltage applied first, and
then get the cathodes warmed up. It is usually the crusty/dusty GZ34
rectifier that still tests as new in the vintge amps using it...
cheers,
Douglas



On the subject of cathode heating, here is an interesting piece:

http://www.chiark.greenend.org.uk/scopes/weyer.txt

Apparently the harm (poisoning) is done to the control grid, which of course
is not present in tube rectifiers. Thus, your example, while interesting,
really doesn't apply.

I just posed a question to my wife's uncle, who is a noted E.E. who used to
do design work in the Tungsol factory. I'll post his answer on the N.G. -
he is as authoritative as any source that I have ready access to. (He got
me all hot and bothered once when he told me he thought he had a case of
Tungsol 6550s in his basement. Unfortunately, they were all gone . . .)

As an aside, you know that CRT restorers work by applying a burst of current
to the tube's cathode(s) to boil off impurities. It is a subtractive process
that eventually (with repeated or excessive application) will strip the
cathodes to hell.

From an engineering perspective, using an indirectly heated rectifier seems
to offer the best compromise, not the least of which is simplicity.

Jon

[Iain Churches[_2_]]

"PeterD" wrote in message
...
On Tue, 06 Nov 2007 22:39:13 GMT, "Dave" wrote:

Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.


If you are building a tube amp, then it seems only proper to use a
tube rectifier...

But...

A delayed B+ is viable. There used to be a number of delay units that
looked like tubes for this purpose. They had a heater, a bi-metalic
strip and a set of contacts. IIRC you could get a number of different
delay times.

Hi Dave.

There are many sorts of timers you could use, but my choice is the
glowing bottle solution, the DLS 16 thermal relay. It has an octal base
and a glass envelope like a stubby 6SN7.

It has a 6.3V heater which is incandescent. The relay consists of
a bimetal strip, which after about 45 secs switches to the normally
open contacts. You can set the delay time by experiment, and the use
of a series resistor in the heater wiring.

I never switch the HT directly, but use a power relay on an
octal base, to switch the AC on the secondary of the
mains transformer (The amp in question has a separate
transformer for heaters and bias)

One can wire the DLS16 and the power relay in such a way that
the latter is latching, and so the DLS is only on during the warm
up period. They are plentiful and cheap and should last many
years in this application.


The brightness of the DLS is always a conversation
piece. Then it suddenly goes out, and the amp is running.
Quite an interesting 45 secs as the prelude to a session of
musical enjoyment.

I can probably find a sketch of the wiring diagram I used if
this will be of interest to you.

Best regards
Iain

[David R Brooks]

Dave wrote:
"Andre Jute" wrote in message
oups.com...
On Nov 6, 10:39 pm, "Dave" wrote:
Cathode stripping. I've heard it's bad, and often it's given as a reason
NOT to go SS rectifier. I'm in the process of building an amp, which
calls
for a SS bridge rectifier, but I happen to have a 5U4GB sitting in my box
o'
fun. To be honest I'd rather not waste B+ voltage warming my room with
the
tube rectifier, attractive though it is. Should I be considering some
sort
of turn-on delay to bring up the voltage somewhat slower if I went with
the
solid state device? I don't see anything like that on the various
schematics I've looked at which use silicon rectification.

Dave S.
You're wasting your time, Dave. Cathode stripping is one of those old-
wives tales. If you're all that keen on tube rectification, use a
rectifier tube with a slow startup like the GZ37 (expensive) shown on
some of my circuits like the T39 KISS Amp. If you must build a delay
into a silicon-rectified supply, you could use a thermistor but the
downside is heat. Most of us just don't bother. Most of use have never
seen a cathode-stripped tube, or heard of anyone who stripped one.

As an alternative, I published in Glass Audio about ten years ago a
switching scheme that switches the filaments on before the B+ without
expensive and fragile relays. Again, it is years since I bothered...
But I can dust the drawing off and republish it if you wish.

thanks for offering, but it doesn't sound necessary. I see that the
thermistors with appropriate ratings seem to run 110C at operating current.
As I noted above, the EL84's are cheap and plentiful and with a 2V input
signal can be driven by just about any tube to be found under the sun.

I could ramp up the voltages with a cascade of transistors with delays
controlled by RC networks but that hardly seems right on my first tube amp
;-)

I went with an EL84 PP design because I have the output transformers (I have
no SE transformers at all) and a power transformer that will work, albeit
large and ugly (rated at 500VA). Maybe I'll paint it gloss black and put it
in its' own plexiglass box bathed in blue light or something.

It's also possible (Morgan Jones shows it in one of his examples) to use
a phase-controlled solid-state relay in the transformer primary, and
ramp that up. Of course, you need some kind of auxiliary supply to
bootstrap the relay control. The SSR doesn't cause any noise once it's
fully on.

[tubegarden]

On Nov 6, 5:04?pm, flipper wrote:


I note that manufacturers, at the time, don't seem to have worried much about it.



Hi RATs!

I used to work in the computer bidness. Manufacturers, dear friends,
worry about costs and profits. Or, more pointedly: "The high cost of
profit."

I once got a competitor's product in for performance testing. ( If you
want to know real numbers, collect them yourself. Even if your methods
are delusional, at least the numbers came from the same testbed ...)
It arrived in a very well engineered shipping carton. I summoned
management to see what was possible. They all said: "Waste of money."
That is the mantra of many middle management poser droids (SEE:
Dilbert). That competitor is still in bidness, my former employer
ain't ...

Anyway, cathode stripping is when B+ is applied before the cathode is
at operating temperature and/or before the bias voltage is stable. It
will never cause system failure within the warranty period. So much
for mfgr concern.

______

If you are building an amp for grins, do not worry about cathode
stripping.

If you are building an amp to seriously listen to, do not worry about
cathode stripping. You will build more amps as the various bits of
infomation you accumulate breed in your mind and take over and run
your life. It is fun

Yes, tube rectifiers can sound better, and nothing but money is lost
by having B+ come from a dedicated transformer, which greatly
simplifies pre-heating. Just turn on the filament power first, then B
+. Two switches, both on primary.

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

That leaves bias voltage stability an interesting problem ... unless
you use a cathode resistor for self bias. Fixed bias is a way to
pretend your cheap power transformer is big enough. It ain't. And a
fixed bias network failure can really ruin your day, and will,
eventually.

I built an SE amp which used tube rectification and only one tube
(SV83) per channel. It was not perfect, but, yes, you may simplify
things quite a bit ...

Happy Ears!
Al

[Raymond Koonce]

tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:

snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

snip

Happy Ears!
Al


Hi Al,

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

Raymond

[Iain Churches[_2_]]

"Raymond Koonce" wrote in message
...
tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:
snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

Thanks Raymond. This same switch configuration was published years
ago in Glass Audio. You saved me a lot of thumbing:-)

Iain

[Raymond Koonce]

Iain Churches wrote:
"Raymond Koonce" wrote in message
...
tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:
snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

Thanks Raymond. This same switch configuration was published years
ago in Glass Audio. You saved me a lot of thumbing:-)

Iain


You're welcome. I think I happened on this scheme in Sound Practices
and I've used it ever since. On the last two amps I built, however, I
used a time delay relay made by Sofia Electric. It provides approx. 30
second delay before switching a relay. I believe the delay is
adjustable with the replacement of one resistor.

Raymond

[John Byrns]

In article ,
Raymond Koonce wrote:

tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:

snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

snip

Happy Ears!
Al


Hi Al,

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

There is a drawing error in this schematic which causes it to not work
as advertised, the problem is in the connection to the south west
terminal of the bottom switch.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Raymond Koonce]

John Byrns wrote:
In article ,
Raymond Koonce wrote:

tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:

snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

snip
Happy Ears!
Al


Hi Al,

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

There is a drawing error in this schematic which causes it to not work
as advertised, the problem is in the connection to the south west
terminal of the bottom switch.


Regards,

John Byrns

John,

You have sharp eyes!! Thanks for spotting the error. It's fixed.

BR,

Raymond

[Iain Churches[_2_]]

"John Byrns" wrote in message
...
In article ,
Raymond Koonce wrote:

tubegarden wrote:
On Nov 6, 5:04?pm, flipper wrote:

snip

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

snip

Happy Ears!
Al


Hi Al,

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

There is a drawing error in this schematic which causes it to not work
as advertised, the problem is in the connection to the south west
terminal of the bottom switch.


John. Please elaborate.
Thanks
Iain

[John Byrns]

In article i,
"Iain Churches" wrote:

"John Byrns" wrote in message
...
In article ,
Raymond Koonce wrote:

tubegarden wrote:

There is a circuit which turns on filaments first, no matter which
switch you throw first. I don't have it at hand. Figure it out It
also shuts off B+ first ...

Hi Al,

Here's a link to a schematic which uses that switching scheme. It's
simple and foolproof. Takes two DPST switches (DPDT and don't use half).

http://www.timebanditaudio.com/james...schematic.html

There is a drawing error in this schematic which causes it to not work
as advertised, the problem is in the connection to the south west
terminal of the bottom switch.

John. Please elaborate.

Iain, look here http://fmamradios.com/1vs2.gif to see the relevant
portions of the original and corrected schematics. The original is on
the left, the corrected schematic is on the right, notice the difference
in the wiring of the bottom pole of the bottom switch.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Iain Churches[_2_]]

"John Byrns" wrote in message
...

Iain, look here http://fmamradios.com/1vs2.gif to see the relevant
portions of the original and corrected schematics. The original is on
the left, the corrected schematic is on the right, notice the difference
in the wiring of the bottom pole of the bottom switch.


Many thanks, John
I must try to find the schematic in Glass Audio to see if this too
was incorrect.

Regards
Iain

[Raymond Koonce]

Iain Churches wrote:
"John Byrns" wrote in message
...

Iain, look here http://fmamradios.com/1vs2.gif to see the relevant
portions of the original and corrected schematics. The original is on
the left, the corrected schematic is on the right, notice the difference
in the wiring of the bottom pole of the bottom switch.


Many thanks, John
I must try to find the schematic in Glass Audio to see if this too
was incorrect.

Regards
Iain




Iain,

It's correct in Glass Audio. That was my drawing error. The drawing on
the right in John's link is the correct one. As soon as he pointed it
out, I made the correction.

Regards,

Raymond

[Iain Churches[_2_]]

"Raymond Koonce" wrote in message
...
Iain Churches wrote:
"John Byrns" wrote in message
...

Iain, look here http://fmamradios.com/1vs2.gif to see the relevant
portions of the original and corrected schematics. The original is on
the left, the corrected schematic is on the right, notice the difference
in the wiring of the bottom pole of the bottom switch.


Many thanks, John
I must try to find the schematic in Glass Audio to see if this too
was incorrect.


It's correct in Glass Audio. That was my drawing error. The drawing on
the right in John's link is the correct one. As soon as he pointed it
out, I made the correction.

Excellent. Raymond. Thanks. It's a useful and ingenious
way to implement a fool-proof warm start.

Iain

[[email protected]]

On 7 nov, 01:55, Dédé Jute wrote:

Perception is a skill that requires study and careful development over
along period of time. Few have it as a natural gift. -- Iain Churches

Thousands years of history to read such... hmmm.
Hey Dédé where do you find your citations ? On the fireman calendar ?

http://gothamist.com/images/2003_7_fdnycal.jpg

:-D

[Dersu Uzala]

What do you guys think about this article?

http://www.audioxpress.com/magsdirx/...lespie2544.pdf

This discusses several methods, including turn-on delays for extending tube
life.