[Freddie]

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

[Stephen Cowell]

"Freddie" wrote in message
...
I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.

This has me flummoxed... I'm trying to imagine what 'leaking
current from the face plate' means, and I'm coming up empty.

....

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

Tom Mitchell's "How To... " is what I recommend.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Torres is not a name that goes down well around here... that said, if
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.
__
Steve
..

[Peter Wieck]

On Nov 29, 10:32 pm, "Stephen Cowell"
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.

Possibly he is suggesting AC leakage across the amp chassis as felt by
that little 'vibration' one gets from a light touch to poorly grounded
parts?

Maybe line-bypass caps that are leaky? Lots of other possibilities as
well. One way or another, not an amp I would use until straightened
out.

To that end:

Freddie:

Get that amp to a service tech forthwith. DO NOT pass go, DO NOT use
it until you have solved that problem with absolute certainty. If you
are not a tech yourself, find a competent one. Lethal currents reside
in tube amps, and problems such as you describe (if I understand it
correctly) can really reach out and "touch" you.

And, it could be as simple as a few caps.

Peter Wieck
Wyncote, PA

[J.P.]

On Thu, 29 Nov 2007 19:50:33 -0800 (PST), Peter Wieck
wrote:

On Nov 29, 10:32 pm, "Stephen Cowell"
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.

Possibly he is suggesting AC leakage across the amp chassis as felt by
that little 'vibration' one gets from a light touch to poorly grounded
parts?

Maybe line-bypass caps that are leaky? Lots of other possibilities as
well. One way or another, not an amp I would use until straightened
out.

To that end:

Freddie:

Get that amp to a service tech forthwith. DO NOT pass go, DO NOT use
it until you have solved that problem with absolute certainty. If you
are not a tech yourself, find a competent one. Lethal currents reside
in tube amps, and problems such as you describe (if I understand it
correctly) can really reach out and "touch" you.

And, it could be as simple as a few caps.

Peter Wieck
Wyncote, PA
Might be the DEATH CAP starting to short out....! Might be getting
real dangerous ...!

[Axtman]

"J.P." wrote in message
...
On Thu, 29 Nov 2007 19:50:33 -0800 (PST), Peter Wieck
wrote:

On Nov 29, 10:32 pm, "Stephen Cowell"
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.

Possibly he is suggesting AC leakage across the amp chassis as felt by
that little 'vibration' one gets from a light touch to poorly grounded
parts?

Maybe line-bypass caps that are leaky? Lots of other possibilities as
well. One way or another, not an amp I would use until straightened
out.

To that end:

Freddie:

Get that amp to a service tech forthwith. DO NOT pass go, DO NOT use
it until you have solved that problem with absolute certainty. If you
are not a tech yourself, find a competent one. Lethal currents reside
in tube amps, and problems such as you describe (if I understand it
correctly) can really reach out and "touch" you.

And, it could be as simple as a few caps.

Peter Wieck
Wyncote, PA
Might be the DEATH CAP starting to short out....! Might be getting
real dangerous ...!

That was my guess! The "face plate" leaking probably means that he is
getting tha uncomfortable "tickling" feeling from touching the amp's face
plate.

-David

[boardjunkie]

On Nov 29, 5:42 pm, Freddie wrote:
I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

There is a .047 600v capacitor that is tied from the fuseholder to the
chassis. Snip it out. If you have a grounded 3 wire pwr cable, make
sure the green ground wire is soldered firmly to the chassis (or the
lug thats bolted to the chassis) and make sure your outlet is wired
correctly (not ground defeated).

[Freddie]

On Nov 29, 7:32 pm, "Stephen Cowell" wrote:
"Freddie" wrote in message

...

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.

This has me flummoxed... I'm trying to imagine what 'leaking
current from the face plate' means, and I'm coming up empty.

I turned the amp on and let it sit for about 30 seconds. Then I use a
multi-meter to measure the voltage from the face plate to a water pipe
in the garage. I don't remember what the reading was now, but it seem
high at the time.

I plugged into it since I got a bad shock a while back. I got shocked
by the guitar, then by the guitar jack on the amp when I wen to plug
the guitar. Even the cable's metal tip was hot to the touch.

...

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

Tom Mitchell's "How To... " is what I recommend.

I'll check it out.


As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Torres is not a name that goes down well around here... that said, if
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.
__
Steve
.

[Freddie]

I plugged into it since I got a bad shock a while back. I got shocked
by the guitar, then by the guitar jack on the amp when I wen to plug
the guitar. Even the cable's metal tip was hot to the touch.

TYPO:
I meant to say I haven't plugged into it since I got a bad shock.

[jh]

Freddie schrieb:
On Nov 29, 7:32 pm, "Stephen Cowell" wrote:
"Freddie" wrote in message

...

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.
This has me flummoxed... I'm trying to imagine what 'leaking
current from the face plate' means, and I'm coming up empty.

I turned the amp on and let it sit for about 30 seconds. Then I use a
multi-meter to measure the voltage from the face plate to a water pipe
in the garage. I don't remember what the reading was now, but it seem
high at the time.

I plugged into it since I got a bad shock a while back. I got shocked
by the guitar, then by the guitar jack on the amp when I wen to plug
the guitar. Even the cable's metal tip was hot to the touch.



DEATH CAP



it *has* to be removed and the PE (protective earth) has to be installed
*and* checked for proper function. The PE is your life insurance

regards

Jochen




...

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.
Tom Mitchell's "How To... " is what I recommend.

I'll check it out.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).
Torres is not a name that goes down well around here... that said, if
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.
__
Steve
.

[Freddie]

On Nov 29, 7:50 pm, Peter Wieck wrote:
On Nov 29, 10:32 pm, "Stephen Cowell"

they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.

Possibly he is suggesting AC leakage across the amp chassis as felt by
that little 'vibration' one gets from a light touch to poorly grounded
parts?

Maybe line-bypass caps that are leaky? Lots of other possibilities as
well. One way or another, not an amp I would use until straightened
out.

To that end:

Freddie:

Get that amp to a service tech forthwith. DO NOT pass go, DO NOT use
it until you have solved that problem with absolute certainty. If you
are not a tech yourself, find a competent one. Lethal currents reside
in tube amps, and problems such as you describe (if I understand it
correctly) can really reach out and "touch" you.

And, it could be as simple as a few caps.

I was thinking that it's probably some cap going bad. Probably
replacing all the big caps around the power supply will resolve the
problem. Maybe I'll just bring it in to a pro instead. There's a
company call King Amplification close to my work. Their amps are
expense, and I'm sure the labor is too. Cheaper than a funeral
though.


Peter Wieck
Wyncote, PA

[Phil S.]

"Stephen Cowell" wrote in message
...

"Freddie" wrote in message
...
I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.

This has me flummoxed... I'm trying to imagine what 'leaking
current from the face plate' means, and I'm coming up empty.

...

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

Tom Mitchell's "How To... " is what I recommend.

I'll second that recommendation. It can be purchased with a video. I've
got the book only and hardly look at it any more, but it was a great
starter. Don't buy this from Amazon or B&N unless you confirm it is
in-stock. Amazon too 6 weeks to deliver it. There are specialty places
that keep it in stock and will deliver quickly and you should confirm that
it is not a special order or you will be waiting a long time. You can see
the title he
http://www.elderly.com/books/cats/603.5.html
http://musicbooksplus.com/bhow-servi...pb-p-1043.html
http://www.tubesandmore.com/scripts/...TREE02=2008118

The last one, tubesandmore, I'm reasonably sure they stock it. Sometimes
these can be had on eBay for a decent discount. No harm in getting it
there.


As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Torres is not a name that goes down well around here... that said, if
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.
__
Steve
.

[Phil S.]

If you want some basic info, particularly on the death cap and 3-wire power
supply cord, you will find reliable info he
http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/
Snipping the death cap and doing the 3-prong is fairly simple for any
mechanically inclined person. Read the safety part, too, and take it very
seriously.

[Peter Wieck]

On Nov 29, 11:52 pm, boardjunkie wrote:
On Nov 29, 5:42 pm, Freddie wrote:





I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

There is a .047 600v capacitor that is tied from the fuseholder to the
chassis. Snip it out. If you have a grounded 3 wire pwr cable, make
sure the green ground wire is soldered firmly to the chassis (or the
lug thats bolted to the chassis) and make sure your outlet is wired
correctly (not ground defeated).- Hide quoted text -

- Show quoted text -

Uh, and that there actually is a working ground at that (and every
outlet) you use for this amp.

Also: DO NOT ASSUME that by cutting the bypass cap (that is there to
'reduce' turn-on thump) that you have automagically solved the
problem. The condition of that cap is indicative of the rest of the
amp, not unique unto itself. Get it serviced properly.

Not every gig can guarantee you a good electric source.

Peter Wieck
Wyncote, PA

[boardjunkie]

On Nov 30, 8:48 am, Peter Wieck wrote:
On Nov 29, 11:52 pm, boardjunkie wrote:





On Nov 29, 5:42 pm, Freddie wrote:

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

There is a .047 600v capacitor that is tied from the fuseholder to the
chassis. Snip it out. If you have a grounded 3 wire pwr cable, make
sure the green ground wire is soldered firmly to the chassis (or the
lug thats bolted to the chassis) and make sure your outlet is wired
correctly (not ground defeated).- Hide quoted text -

- Show quoted text -

Uh, and that there actually is a working ground at that (and every
outlet) you use for this amp.

Also: DO NOT ASSUME that by cutting the bypass cap (that is there to
'reduce' turn-on thump) that you have automagically solved the
problem. The condition of that cap is indicative of the rest of the
amp, not unique unto itself. Get it serviced properly.

Not every gig can guarantee you a good electric source.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

Turn on thump....with a tube amp? Riiiiiight......might keep that
little slide switch from wearing out so fast tho.

[Jim]

Freddie wrote:

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.

You have a voltage potential at the chassis?

My guess is that your wall isn't supplying a good ground, and/or your
"death cap" is still there, and/or the three prong cord is not installed
correctly.

You can buy a line tester with LEDs at Radio Shack or Home Depot to
verify correct line wiring. You can find schematics and instructions
online on how to convert 2 wire death cap to 3 prong grounded.

You don't sound like the average novice. You know enough to realize
that filter caps can RUIN your day, or WORSE!

If it hasn't already been done, that amp needs all new electrolytic caps
(at a minimum) and I'd be testing the old carbon comp resistors to see
how far they have drifted. Then clean the pots, tube sockets, jacks;
retension jacks and tube pins...

I'm not sure you need a whole lot more to solve this problem. If you're
still uncomfortable and feel the need for a book, it's a good sign that
you're much better off just paying a tech!



It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

[J.P.]

On Thu, 29 Nov 2007 23:14:43 -0800 (PST), Freddie
wrote:

On Nov 29, 7:50 pm, Peter Wieck wrote:
On Nov 29, 10:32 pm, "Stephen Cowell"

they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.

Possibly he is suggesting AC leakage across the amp chassis as felt by
that little 'vibration' one gets from a light touch to poorly grounded
parts?

Maybe line-bypass caps that are leaky? Lots of other possibilities as
well. One way or another, not an amp I would use until straightened
out.

To that end:

Freddie:

Get that amp to a service tech forthwith. DO NOT pass go, DO NOT use
it until you have solved that problem with absolute certainty. If you
are not a tech yourself, find a competent one. Lethal currents reside
in tube amps, and problems such as you describe (if I understand it
correctly) can really reach out and "touch" you.

And, it could be as simple as a few caps.

I was thinking that it's probably some cap going bad. Probably
replacing all the big caps around the power supply will resolve the
problem. Maybe I'll just bring it in to a pro instead. There's a
company call King Amplification close to my work. Their amps are
expense, and I'm sure the labor is too. Cheaper than a funeral
though.


Peter Wieck
Wyncote, PA
Now we are getting the idea! ...and then go read some amp stuff until
you have it down pat.....

[J.P.]

On Fri, 30 Nov 2007 08:39:01 -0500, "Phil S."
wrote:


"Stephen Cowell" wrote in message
.. .

"Freddie" wrote in message
...
I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse.

This has me flummoxed... I'm trying to imagine what 'leaking
current from the face plate' means, and I'm coming up empty.

...

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

Tom Mitchell's "How To... " is what I recommend.

I'll second that recommendation. It can be purchased with a video. I've
got the book only and hardly look at it any more, but it was a great
starter. Don't buy this from Amazon or B&N unless you confirm it is
in-stock. Amazon too 6 weeks to deliver it. There are specialty places
that keep it in stock and will deliver quickly and you should confirm that
it is not a special order or you will be waiting a long time. You can see
the title he
http://www.elderly.com/books/cats/603.5.html
http://musicbooksplus.com/bhow-servi...pb-p-1043.html
http://www.tubesandmore.com/scripts/...TREE02=2008118

The last one, tubesandmore, I'm reasonably sure they stock it. Sometimes
these can be had on eBay for a decent discount. No harm in getting it
there.


As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Torres is not a name that goes down well around here... that said, if
they can sell you a non-leaky face plate, I'd go for it. That is, if I
understood what 'face-plate leaking' was all about.
__
Steve
.



Didn't TM used to hang in here? I bought a copy of his right before he
moved to Georga or somewhere like that from Cal but have never seen
him post since....not a bad book to get an idea..

[Peter Wieck]

On Nov 30, 2:19 pm, boardjunkie wrote:
On Nov 30, 8:48 am, Peter Wieck wrote:





On Nov 29, 11:52 pm, boardjunkie wrote:

On Nov 29, 5:42 pm, Freddie wrote:

I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

There is a .047 600v capacitor that is tied from the fuseholder to the
chassis. Snip it out. If you have a grounded 3 wire pwr cable, make
sure the green ground wire is soldered firmly to the chassis (or the
lug thats bolted to the chassis) and make sure your outlet is wired
correctly (not ground defeated).- Hide quoted text -

- Show quoted text -

Uh, and that there actually is a working ground at that (and every
outlet) you use for this amp.

Also: DO NOT ASSUME that by cutting the bypass cap (that is there to
'reduce' turn-on thump) that you have automagically solved the
problem. The condition of that cap is indicative of the rest of the
amp, not unique unto itself. Get it serviced properly.

Not every gig can guarantee you a good electric source.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

Turn on thump....with a tube amp? Riiiiiight......might keep that
little slide switch from wearing out so fast tho.- Hide quoted text -

- Show quoted text -

Yo, Junkie... Ya got me there... Too much $%^&* SS stuff across the
bench lately that I have my bypass caps confused a bit. Pull that cap
and watch the woofer cones bottom...

But and all-at-the-same-time, that cap was put there for a reason. And
a properly sized and typed (new) cap should remain there for the same
reason.

Peter Wieck
Wyncote, PA

[Stephen Cowell]

"J.P." wrote
....

Didn't TM used to hang in here? I bought a copy of his right before he
moved to Georga or somewhere like that from Cal but have never seen
him post since....not a bad book to get an idea..

Yes, he is in and out here often enough, at least once a year.
__
Steve
..

[Phil S.]

"Peter Wieck" wrote in message
...
On Nov 30, 2:19 pm, boardjunkie wrote:
On Nov 30, 8:48 am, Peter Wieck wrote:





On Nov 29, 11:52 pm, boardjunkie wrote:

On Nov 29, 5:42 pm, Freddie wrote:

I have an old Silverface Champ(AA764) I purchased a while back.
It's
leaking current from the face plate and it's getting worse. It
just
sits in the garage now. It has 3 prong cord when I brought it, but
I
have no idea if that was done right. I've replaced the power tube
and
rectifier, but not the preamp tube.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage
digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy
of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that
covers
more practical matters like maintenance and safety. I like
pictures
too, especially if they resemble what my Fender will look like
inside.

As a side issue, does anyone have a preference for which vendor to
get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

Thanks,
Freddie

There is a .047 600v capacitor that is tied from the fuseholder to
the
chassis. Snip it out. If you have a grounded 3 wire pwr cable, make
sure the green ground wire is soldered firmly to the chassis (or the
lug thats bolted to the chassis) and make sure your outlet is wired
correctly (not ground defeated).- Hide quoted text -

- Show quoted text -

Uh, and that there actually is a working ground at that (and every
outlet) you use for this amp.

Also: DO NOT ASSUME that by cutting the bypass cap (that is there to
'reduce' turn-on thump) that you have automagically solved the
problem. The condition of that cap is indicative of the rest of the
amp, not unique unto itself. Get it serviced properly.

Not every gig can guarantee you a good electric source.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

Turn on thump....with a tube amp? Riiiiiight......might keep that
little slide switch from wearing out so fast tho.- Hide quoted text -

- Show quoted text -

Yo, Junkie... Ya got me there... Too much $%^&* SS stuff across the
bench lately that I have my bypass caps confused a bit. Pull that cap
and watch the woofer cones bottom...

But and all-at-the-same-time, that cap was put there for a reason. And
a properly sized and typed (new) cap should remain there for the same
reason.

Peter Wieck
Wyncote, PA

I dunno. I got a nice black beauty out of a Gibson that I've been saving
for use as a tone cap sometime. Waste of an expensive cap, not in the tone
path. I know, in 1966 these were ordinary, but that is the effect of time.
It's a Sprague 0.022mf 600v, so it's going to find a home in one of my amps
soon enough. Maybe that TW Express I'm about to build. I also have a .05mf
400v Astron.

[Harrison Ford Prefect]

Freddie wrote:
I have an old Silverface Champ(AA764) I purchased a while back. It's
leaking current from the face plate and it's getting worse. It just
sits in the garage now. It has 3 prong cord when I brought it, but I
have no idea if that was done right. I've replaced the power tube and
rectifier, but not the preamp tube.

You don't have to wait for the book for this one.

http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/Mods/
(look for the link on making it safe)

The general stuff here applies to the proper power cord
setup for any amp, not just the Kalamazoos. Only the
physical layout changes with the amp.

My background in electronics is some EE classes and labs in college
over 10 years ago. Unfortunately, that was mostly low wattage digital
stuff. I'm reading "Inside the Vacuum Tube" now and I have a copy of
the Schematic and Layout for my Amp.

What I'm looking for is a beginner's tube amp repair book that covers
more practical matters like maintenance and safety. I like pictures
too, especially if they resemble what my Fender will look like inside.

OK, if you think you *need* those, the above may not help.
But check it out and see.

As a side issue, does anyone have a preference for which vendor to get
the replacement parts from? I was thinking of either Allen Amps or
Torre Engineering(local).

I buy tubes from Lord Valve and most other parts from
the wholesale arm of Antique Electronics (www.tubesandmore.com).

[Freddie]

You don't have to wait for the book for this one.

http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/Mods/
(look for the link on making it safe)

That's a great link.

Thanks,
Freddie