Help with F5 with Gamut style MOSFET's

[Sweetsweetback]

Do I spot a shorted turn between the transformers and the aluminum plate connecting them via the mounting bolts?

[Uunderhill]

Originally Posted by juma

I'm really not a wire aficionado but that's clearly a sub-optimal setup - search for some successful build's pictures and you'll get it, good wiring techniques are explained and shown many times on this forum...

I'm still learning here.

I stole the idea of gluing the electrolytics down with a hot glue gun and using P to P wiring from the Blue Circle BC 1022 amplifier.

P1010474 | Flickr - Photo Sharing!

However, if I were to do it again, probably would have used an FR-4 board with a focused ground area.
But hind site is wonderful.

Also, I would have BOUGHT A PRE MADE CASE !!! instead of making it.

However, mounting the 2 toroids in the back of the amp worked out well - resulting in running short AC lines inside the amp.

I was a bit concerned about in rush current when the amp was switched on
so dual power switches were installed.

The technique of mounting the bridges above the power toroids seems to be pretty common.

The green wires running from the diode bridges are connected to the ground focus point.
The Mundorf film caps focus in on that node too.
.

[Uunderhill]

Originally Posted by Sweetsweetback

Do I spot a shorted turn between the transformers and the aluminum plate connecting them via the mounting bolts?

Lord NO !!!

There is a rubber washer - then the toroid's metal washer - and the aluminum plate sits above that.
So the aluminum plate sits at least an 1/8" above the windings.
.

[Zen Mod]

think more

if screw heads have connection with base plate , then also with Al plate on top - you have shorting turn through both donuts

[tinitus]

ah, now I know why it sounded better once I tried to isolate the mounting screw from chassis
hey, btw, it also sounds better using brass screws, it really does

[Zen Mod]

brass screws are also conducting AC current

so - you screwed something else , if that worked better

[tinitus]

non magnetic

btw, how is it conducting anything if its totally isolated from anything else, with isolators ?

[juma]

Originally Posted by tinitus

non magnetic

btw, how is it conducting anything if its totally isolated from anything else, with isolators ?

That's the first thing Faraday asked himself too when he noticed the current flow through the conductor that was close to the moving magnet

[Uunderhill]

Originally Posted by Zen Mod

if screw heads have connection with base plate , then also with Al plate on top - you have shorting turn through both donuts

I don't understand.

Both the case and the aluminum plate are at the same voltage potential.

The donuts are electrically insulated from the case by the large rubber washer on both the top and bottom, supplied by Antek.

Do you mean the donuts are talking to each other through the stainless steel mounting bolts ?
I thought the idea of the donut was that all the flux lines stayed inside the core ?
Can stainless steel be picked up by a magnet ?

Do they make 5/16" nylon bolts ?

[Uunderhill]

Originally Posted by juma

That's the first thing Faraday asked himself too when he noticed the current flow through the conductor that was close to the moving magnet

OK - I just checked.

A 1" diameter neodymium magnet has a just a hint of a pull on a bolt (machine screw ?) made from 304 stainless steel.

Do you you think the donuts are talking to each other by inducing a current in the stainless bolts ?