Spring Line Hum

[Harry Bissell]

As I chimed in in my first post... My first choice would be Mu-Metal
shielding...
but check out Advance Magnetics and other suppliers, and you will
discover it
is very pricey. It is the "Silver" (er... well Nickel - Chromium etc)
bullet for magnetic
flux !!!

H^) harry.

John Speth wrote:

>
>
> All this talk of hum can't possibly be that difficult.  (Coming from a
> guy with no experience :) ).  I have an old Yamaha G212 guitar amp
> with a 1 foot long reverb tank.  It's mounted right on the head.  Both
> the head and the tank are made of that yellowish metal.  When the
> volume is turned up to 10 and the reverb is turned up to 10, you hear
> practically no hum.  And you can't hear any difference rotating the
> reverb control full on to full off.
>
> So the hum problem certainly must be preventable.  I haven't got any
> schematics for the amp so I don't know what circuitry drives it.  But
> I'll bet the secret is in just-the-right shielding - a low tech
> solution that Yamaha has shown to work well.  So isn't sheilding the
> tank the solution?  Seems non-elegant over-engineer an
> under-engineered problem.
>
> John Speth
> Molectron Detector, Inc.
> http://www.molectron.com
> mailto:johns at molectron.com