Hi,

I would very much appreciate a minute of your time.



The sum of my knowledge of electrical safety basically amounts to knowing a
three-prong adapter on a two-prong plug doesn't ground an appliance, but
having caught the "vintage virus" recently, I went shopping on eBay for a
low-wattage guitar amp.



A hand-wired, point-to-point, class A vintage tube amp for that "mojo'
tone - that's the ticket! My ignorance was bliss.



I think I have begun a journey to actually learning a thing or two about a
crucial subject, but for now I am overwhelmed to the point that I've
concluded it is not safe for me to buy a vintage amp for home use. I value
the lives of my loved ones, myself included.



What troubles me is the idea of less-suspecting musicians buying into a
potentially lethal decision. Approaching a group of "tube-heads" for simple
safety advice is inviting derision, but conscientiously I must. Call it my
civic-duty or anal-retentiveness, but I will feel irresponsible if I don't.



Will you guys and gals please share your educated, or hard-learned, or
innate electrical common sense and offer your suggestions for essential
rules of safety for musicians buying vintage amplifiers?



This is a serious inquiry. I recently initiated and then negotiated out of
the purchase of a Silvertone 1451. I liked the way it looked, the price was
right, and the seller said he had performed a complete cap job. Only because
this model was so rare did I have to search endlessly for nights on end to
come to the conclusion that I better not get it.



Realizing it may be difficult to put yourself in an idiot's shoes (not that
you'd care to), below is my personal example to which I'm not asking
specific answers except as in regards to a bigger picture of more general
safety rules:



This is what little I know and the conclusions, right or wrong, that I came
to:

The tube lineup was 50C5, 35W4, and 12AU6 which I think puts it in the
"Radio tube" amp class. Now I believe it has a power transformer, so I think
that means it does not have a "death cap".

It probably does not have an isolation transformer, a schematic is on the
way.

Soooo. the two prong plug must be correctly plugged into the outlet first of
all. Even so, I believe there are extenuating circumstances that could still
make the chassis "hot" and possibly the simultaneous touching of the guitar
and chassis, or guitar and mic, or other loop could be dangerous.

I think that one solution would be to properly install a three-prong plug
using the following example:

"With the unit unplugged and the filter caps discharged, cut or de-solder
the old, two-wire, line cord from the fuse and switch. While you're at it,
get rid of the cap from the switch to chassis ground (leave that ground lug,
though!)" http://www.rru.com/~meo/Guitar/Amps/...Mods/safe.html





and run the ground to the ground lug, the black to the fuse (install a fuse
if not present) and white to the transformer. I am still unclear if adding
an isolation transformer is necessary once this has been accomplished.



So you can see the mess I got myself in. A lot of these amps are being
listed on eBay because people are paying stupid money for anything with a
tube in it. A lot of three-prong plugs have been added and hopefully
correctly, but that too should be assessed with caution.



I'm hoping for a check-list kind of guide or rules set or possible scenarios
that could serve as a warning to others. A list of known problem amps and
designs or a link to such would be helpful.



If that proves impractical or ill-advised in its own right, then at least I've
tried to address this issue. I'm not trying to minimize the precautions and
warnings already advocated by you guys and every other safety advocate. I'm
just hoping for something new that will reach the people like me - uniformed
ebayers potentially buying more than they bargained for.



If you've read this far then I thank you very much for your consideration.

Sincerely, Dan



Silvertone, Harmony, Sears, Wards, Valco, Supra, Heath, Bogen,

Gibson, Fender,