Another Next Best Tweak

The back of the transformer is the farthest point from the front of the
amplifier, with magnets placed on their side. Since the magnet is shaped
like a tire, the contact point of the magnet is like the side that faces the center of the car at all times.

On my Marsh A400 there are five wires
that go from the top of the transformer to the circuit board.
The three magnets are placed (clock analogy) at ten, twelve
(the center of the group of wires) and two.
This sounded better to me than placing them farther apart,
at eight, twelve, and four, for example.

When I remove the magnets after a while, I can feel
them continuing to vibrate in my hand for a few seconds!

I agree that placement on top thins out the sound. On my unit,
the magnetic attraction is very strong on top, and relatively weak
on the sides!

I me enjoying the WA Quantum transformer chip placed on top
of the transformer. Have you played with these, yet?

Ozzy,
With neodymium magnets just put them on the outside of the chassis on top or on bottom -- wherever there is a transformer.

What if the chassis is not magnetic???

Here is a bonus: clean the magnets with BRASSO
and then treat with a contact enhancer, before returning them
to service! I use Stabilant...

I tried them on my DIY Ground Control cables. They work good there. But I did notice that having the magnets away from the DIY Ground Control connectors at least 1 inch but no more the 2 inches makes a big difference in bang or bust in sound. So you may have to slowly (tweak) move the magnets towards the connector to lock in the best sound.

Ozzy,
I just put 8 neodymium magnets as a single rod about 3" under my power conditioner. They are super strong. Each one is 1" x 1" x 1/2" square. The effect is stunning. I will be doing a lot more experimenting in the coming weeks using these strong magnets.