The Paul Hynes SR4 PSU

[TheAttorney]

A comprehensive review of the SR4 just in at audiobacon  here

Including comparisons to rival units, including the SR7 DR.

In short, he loves it (and the SR7)

[TheAttorney]

The SR7 used for comparison was the DR version.

 

Somewhere in the review was a hint from Paul that the SR5/7 production may get resurrected if negotiations go well with getting a 3rd party to build them. Something like that. 

[TheAttorney]

35 minutes ago, str-1 said:

I appear, unintentionally, to have irritated a few people over on the Head-fi Mscaler thread raising my concern about Chord’s prohibition on using power supplies other than the one provided in the warranty text.  It’s probably a subject too sensitive to talk much about now.

 

I didn't notice anyone getting particularly irritated - the Chord sponsor was merely pointing out the strict new warranty rules - because some people do stupid things (rather than there being anything abnormal about the m-scaler load). Apart from that, Rob has previously posted that the m-scaler can be driven by lower voltages than 15v. I can't remember what the exact minumum was, but 12v was definitely within the range.

 

As the m-scaler draws no more than 18w, I don't see any reason why an SR4 couldn't drive it. I'll certainly be trying my SR7 when I get the chance, but that won't be for months because I won't be buying the m-scaler before I can properly demo it.

 

So yes, the warranty aspect is a concern - some will be more concerned than others.

 

 

[TheAttorney]

Of around 10 various audiophile fuses I've owned, one has blown as follows after being in use for a few months...

 

My SR Blue failed in my PH SR7 when driving low power digital-only components (mR, IR and Chord m-scaler). All components had been on for several hours when the fuse blew and, in general, the SR7 is left powered 24/7. The Blue fuse was same rating as stock (3.15A slow blow). So, a fuse that should be able to handle around 700w continuous power failed with a load I estimate to be under 40w.

 

The UK dealer did accept my explanation and gave a free replacement - this time I up-rated to 4A. This worked fine up to the point I upgraded it to SR Orange, which I further up-rated to 5A. I had no qualms in that extra up-rating because...

 

The older bespoke SR7's do not have protection circuitry, because at the time Paul found that all protection circuits degraded SQ. And one of the most likely accidents is to short the output plug when messing about with cables or adjusting/measuring voltage output. When this happens, the SR7 will dutifully try to output infinite current into the zero load and within a tiny fraction of a second the regular will blow - well before the fuse has even realised there's a problem.

 

So in such designs, the slow blow fuse is useless (although possibly of some value in other types of equipment/supply error situations). This probably does not apply to the newer T models with built in protection circuits.

 

BTW, the SR Orange definitely sounds better than the Blue, even though I was already impressed with the Blue.