PSU1 cables

You might like to read from page 8 of this thread.
http://audio-forum.gspaudio.co.uk/solo-diamond-ultra-linear-oh-my-god_topic1653_page8.html

Topic moved here to Power Sources as it did not belong in Graham Slee Headphone Amps

I'd like to thank Richard for dropping off his mains leads for us to try.

Construction is quite solid, and we used the longer cable of the two. The cable is quite stiff, but it could still be formed to (only just) reach between the nearest socket and one of our PSU1 caddy PSU1's.

Termination at the mains socket end is by a 56 series IP66 industrial 13A plug with its locking ring removed. Here's an example of the straight variety: http://www.screwfix.com/p/clipsal-56-series-ip66-13a-plug/10586

The fig8 end is a F*r*t*ch cable mounted socket (female plug) which retails at nearly £40.

The cable in-between is printed with the product's name. On inspection through the clear plastic 56 series plug, without taking it apart, it looks like the wire is silver plated or stranded silver wire. The cable has a screen/shield connected to the earth pin, along with the earth wire, but it isn't used to conduct either because the fig8 end is just live and neutral.

Placed on the cable near either end is a soft-ferrite sleeve, covered with some blue heatshrink.

It has been an idea for us to produce an aftermarket mains lead for the PSU1 that is beefier than the standard cord, but because we have been unable to find a sensibly priced rewirable fig8 cable socket, this hasn't happened yet. We decided to compare Richard's cable with the short lengths of standard lead which comes from the caddy's distribution blocks. These are served by a standard RS Components IEC lead.

We (John C, Leo, and I) noticed the biggest difference by using it on the PSU1 used to power a Majestic DAC. The input to the Majestic DAC was analogue, using my ceramic cartridge preamp, fed by my Sonotone 9TA ceramic cartridge.

We played And You And I plus Siberian Khatru on side two of Close To The Edge by Yes. The turntable was one of our Technics SL12XX which is "bog standard".

Richard's cable had the effect of separating out the instruments and voices (obviously this record is mixed down in the studio as are all of its kind, and the positioning is decided on the mixing desk, not by natural mic placement).

It presented Jon Anderson's voice in Siberian Khatru more centrally between the speakers than we have heard before, and forward of the drum set which has the cymbals being gently tapped, which seemed quite natural, if not veering toward the impressive by giving it some hi-res treatment.

The track And You And I can catch many set-ups out on the lyrics "a man can see the moment's answer to the dream" which is often heard as "a man conceived the moment's answer to the dream", which is how all the lyrics sites would have it... (perhaps they used a different take for the CD?) Richard's cable allowed that to be heard, but it also does it with the standard cable.

Overall, we felt the stereo image had a tad more precision, and tonally it was well distributed, with perhaps a bit of emphasis on the mids, making it very slightly more forward, as well as very slightly wider, and in one place a particular instrument was heard playing hard left.

Not wanting to be outdone, we had a quick experiment using some high voltage copper wire cable (1000V) wired to a normal 13A plug, and spliced to a fig8 end cut from a standard cable.

We first used some heavy duty 2.5mm^2 cross section, but this was found too harsh in the upper registers. It was swapped for some 1mm^2 section cable, which removed the harshness. It did not fully achieve what Richard's cable was doing.

I hunted high and low for a suitable soft ferrite. I would have preferred to have found two to place at similar points to those on Richard's cable, but had to make do with one, and parked it roughly centrally.

This gave a slightly different presentation. It placed Anderson's voice in front of the cymbals, and reproduced the hard left instrument placement. But whereas Richard's cable felt as if Anderson's voice had been yanked into centre stage with great precision, and at highest resolution, our "mock-up" treated it a little softer. Richard's cable made the Sonotone sound more like a decent budget MC, whilst ours made it sound more like a cross between a 1042 and AT95E (both MM's).

I would say the only let down by Richard's cable was a trace of harshness on the busy ending of Siberian Khatru, where we felt the superconducting silver plate or whatever it is, reinforced the mids too much, making the harshness - which incidentally was due to the HF resonance of the Sonotone - more obvious. We felt our hurriedly built cable fared better here.

OK, I guess some will think we're crazy for using a ceramic cartridge for a test like this, but the 9TA is an original and uses an original 70's diamond stylus, and they were the best around in its day. The thing is, it is highly capable of showing up these differences in our system. When using a high quality magnetic these differences may well have been much harder for us in our system to spot.

I would like to thank Richard for the opportunity of trying this aftermarket mains cable. It has given us a challenge to make something that could possibly make a difference ourselves.

Graham