My Setup (new member of AoS)

[Simon P]

OK, as requested, some pictures of the Audiomaster MLS5 with the covers off - or 'tweeters out' as my wife just described it.

If anyone knows anything about them, I'd be very interested to learn more.

A couple of notes:

They're not on their original stands.
That Velcro may have been added at a later date by my brother.
Looking at the slightly dodgy black paint job on the baffle it may have been inflicted by a member of my family rather than the manufacturer



State of the '70s art 'hairy' tweeter

[amandela]

Realy nice setup, Simon. I especially love the Technics SL 1200 running into the Graham Slee phonostage.

What cartridge are you using? Any problems with noise/hum from the Graham Slee?

Amandela

[Simon P]

Realy nice setup, Simon. I especially love the Technics SL 1200 running into the Graham Slee phonostage.

What cartridge are you using? Any problems with noise/hum from the Graham Slee?

Amandela

Thank you for your comments Amandela, most appreciated.

I got the Technics from eBay back in February and added the Tecnoarm which I also bought secondhand. I'm using a Goldring G1042 cartridge on there. I was running a Project Debut before, which whilst it was cheap, it was so noisy I could bearly bring myself to use it. It was like night and day going from that to the Technics, I'm very happy with it

The Graham Slee external PSU makes a very high whine though - I can here it as I'm typing this now. There is some noise on the signal path if I turn the volume up to 2 o'clock, but I never reach that level normally as the amp would vaporise my drivers

I'm interested that you ask about the Graham Slee being noisy - have you experienced or heard of noise problems with them? I'm thinking that replacing the PSU with something better would be a good idea. My hearing rolls off reasonably high, and I end up having to unplug the little PSU when I'm not playing vinyl, as the noise tends to bounce off flat surfaces and follow me round the room It sounds like the HT transformer whining on an old telly, but giving it a tap doesn't make any difference.

Simon

[DSJR]

Simon, can you give me a shout regarding the MLS5's as and when you come to sell them, as I know someone who would be extremely grateful for them. Interesting thing with the "phase step" for the tweeter, which was a popular thing to do in the late seventies. The interesting thing about this is that once you get a couple of meters away from the speaker it becomes totally irrelevant - it's another way of "improving" the 1m on axis frequency response (like adding tons of global feedback to 70's amps to improve the basic distortion figures that all the amateur "experts" regarded as important...

Hairy tweeters aren't as much of a problem as you'd think. Don't try to clean them..

[amandela]

Simon:

I have read reviews suggesting that the Graham Slee pre-amps are prone to RFI in some cases. This is not unusual for phonostages, even some very pricey models. Some audiophiles have noted noise problems with the otherwise superb Aesthetix Rhea (2000 pounds sterling), and that baby is built like a tank.

Phono signals are small, delicate things and therefore highly susceptible to noise problems. Some firms like Zanden and Audio Research put their circuits in heavily shielded chassis. I suspect that the small Graham Slee packaging, although elegant and affordable, does not offer the last word in RFI chassis shielding.

The culprit in your system may be related to component placement. Your system pics show the phonostage sitting next to the Chord DAC64, a no-no. Digital sources can emit heavy amounts of RFI interference that can cause havoc to an unshielded phonostage, so I suggest moving the Graham Slee to another location. Ideally, the Graham Slee should sit as far away as possible from any component housing a large transformer (like the Krell) or any digital source like the DAC64.

Alternatively, If you live in or near a big urban center, you may be picking up RFI from surrounding radio stations. If this is the case, you may want to experiment where you place the GS to minimize noise.

Good luck.

Amandela

[DSJR]

Phono signals aren't anything like as small as RF signals processed in the average FM tuner.

Noise and RF pickup are more to do with inadequate design, rather than "delicate" phono cartridge output IMO..

Get the "new" croft phono stage (with SUT if necessary). No difficulties there and a hand made, hard wired circuit with a cosy glow through the grille.. (www.croftelectroacoustics.co.uk)

[Simon P]

I got to the bottom of the noise problem on my phono stage.

I'd overlooked something completely obvious that was hidden in plain site.

At the bottom of the rack is a Media PC that feeds the DAC. I connect the PC's digital out to the DAC using a decent optical lead. I know that it seems to be commonly believed that fibre is slightly inferior to coax, but I've done it this way so that the PC is electrically decoupled from the audio signal path. I think that keeping the PC electrically decoupled from the DAC is more important (I confess this is just my theory - I haven't tested it ).

After giving that part of the setup a certain amount of thought, it's a shame that I then completely neglected to consider that the ethernet over mains device that is plumbed into the adjacent mains socket _might_ just inject noise into the mains. I unplugged this and no more low level noise from the phono circuit

As this ethernet device is only used to back my FLACs up to a network drive, I can simply unplug it when I'm listening to music. Problem solved

The switched-mode PSU for the Graham Slee stills whistles away though. This is high frequency audible switching noise from the wall wart. It's not going into the signal path at an audible frequency, i.e. I don't hear it through the speakers. I'm going to contact Graham Slee about the Gram Amp PSU, as it's still under warranty and it may just be a fault with mine.

The Croft phono stage looks nice - One day!