Rega P3 Grado hum and MU-metal

Archived from groups: rec.audio.high-end (More info?)

I have a Rega P3 and would like to use a Grado Prestige Gold
cartridge, but the often reported hum problem is an issue. MU-metal
alloy shielding appears to be a solution. What is the best way to
apply this to the turn table?

1. As a layer lying on top of the plinth under the platter
2. As a layer between the motor and the plinth, with a hole for the
shaft
3. Completely wrapped around the motor with a hole for the shaft.

Approach 2 will suffer from the loss of permeability due to hole
drilling. Approach 3 will suffer more loss due to bending the foil
around the motor. What have people done that has worked?

Archived from groups: rec.audio.high-end (More info?)

Most people use it under the platter as it is easily placed and
shields the entire area. It can also be removed easily without damage
if you don't use an agressive adhesive. The issue is overated. Try the
cartridge first if you have not already. The only time that it seems
to bother anyone is the last track if there are some silent passages
as in some classical works. After the record is over as the run-out
track has no signal, it is noticable, but faint and you would have to
be pretty silly to be upset about that. There are other cartridges if
you can't live with it.
-Bill
www.uptownaudio.com
Roanoke VA
(540) 343-1250

"David Molvin" <wa3nko@ix.netcom.com> wrote in message
news:ckpmjh0113j@news2.newsguy.com...
> Good luck!! I used so much of it on a Thorens and Grado combo that
did not
> work I gave up on the Grado!
>
> David
>
>
> "Richard Rateick" <Rateick@michiana.org> wrote in message
> news:ckn2r90rdc@news3.newsguy.com...
> >I have a Rega P3 and would like to use a Grado Prestige Gold
> > cartridge, but the often reported hum problem is an issue.
MU-metal
> > alloy shielding appears to be a solution. What is the best way to
> > apply this to the turn table?
> >
> > 1. As a layer lying on top of the plinth under the platter
> > 2. As a layer between the motor and the plinth, with a hole for
the
> > shaft
> > 3. Completely wrapped around the motor with a hole for the shaft.
> >
> > Approach 2 will suffer from the loss of permeability due to hole
> > drilling. Approach 3 will suffer more loss due to bending the
foil
> > around the motor. What have people done that has worked?

Archived from groups: rec.audio.high-end (More info?)

Symmetrical amplification solved the problem with no other tricks. But
the arm has to be rewired.

Geert Meddens

"Norman M. Schwartz" <nmsz@optonline.net> wrote in message news:<cl6sra02m3f@news2.newsguy.com>...
> "Uptown Audio" <uptownaudio@rev.net> wrote in message
> news:cl48em0dld@news1.newsguy.com...
> > Most people use it under the platter as it is easily placed and
> > shields the entire area. It can also be removed easily without damage
> > if you don't use an agressive adhesive. The issue is overated. Try the
> > cartridge first if you have not already. The only time that it seems
> > to bother anyone is the last track if there are some silent passages
> > as in some classical works. After the record is over as the run-out
> > track has no signal, it is noticable, but faint and you would have to
> > be pretty silly to be upset about that. There are other cartridges if
> > you can't live with it.
>
> Knowing something about a distortion that is really there, and can actually
> be heard under any circumstance is real bothersome (to me). Keeping in mind
> that many audiophiles are bothered by things that are not really there and
> cannot be heard under any circumstance, is seemingly a signicant force
> driving the high-end industry, you have my thoughts on this matter.
> Ex Grado/Linn LP-12, Thorens TD125 owner.