Agreed, But aren't you curious to look at why there might be a difference ? I wasn't joking when I said that removing the case from the Accuphase made no difference. In the case of my pre amp it is unusable without it's steel case and sounds worse - but with good reason- the case greatly reduces the intrusion of RFI into the circuit.

The DNM comparison is interesting as his pre amp (and I beleiive hs power amps) are pretty bandwidth limited and less likely to suffer RFI problems.

Another phono stage I used a few years ago, from a designer firmly in the non ferrous camp, was so prone to RFI that it was laughable. Ultra wideband, high gain curcuit in a largely metal free case....... you see my point?

There are forces at work here, perfectly easy to measure and explain forces and there are others which require a degree of belief

IMO, the screw issue goes firmly into the belief camp.

I think this is a good discussion and well worth having but preferably not now within this NVA thread given Richard's recent threat. It's also a little off topic by now