It wasnt just sockets – looked like a computer box to me…that was why I was so curious about it at the time……

Ive asked sum1 what its called, will let u know if they get back to me…

that was quick!

OK Ive just been told its called an Uninterruptable Power Supply – and it simply supplies a constant 240 volts to ensure your dex stay at a constant speed.

Hope that helps…definitely I have noticed this effect myself, and also lights dimming etc…The power both in the national grid,and in a domestic house, fluctuates depending on demand….its just not exact enough for critical application.

Having said that though. may also be that the Numark dex arent built that well – “Wow and Flutter” are the specs you want to look at in the manual – I do not fully get this but you can research it on the net

– from what I do understand “wow and flutter” specs show the amount of deviation in the frequency occurring due to speeding up and slowing down of the device. This is a sort of unavoidable occurance in decks – and Im guessing the cheaper decks might be worse for this

PS you mention getting technics except for the limited pitch range –
Technics Mk5 G have a button that will make them 16% – quite a cool idea, since the more pitch range you have on the slider, the more sensitive the pitch is to slider movements…with the button you can keep it at the more forgiving 8% until you need it higher….

this sounds like a very needed piece of kit .. i’ll have to try and get hold of one for myself as well…

TBH, the first thing I’d check if the problem is only intermittent is that you don’t have a random bit of grit in the bearings that is occasionally causing a bit of excess friction (oiling the bearings helps too)…

A UPS is essentially a battery supply (for providing backup), that usually contain supply conditioner circuits (to give the switch mode PSU’s common in PC’s a good steady supply with no large spikes or dropouts).

I don’t really have much experience of Numark direct drives, but you can pretty much guarantee that any EMI from other electricals in close proximity will manifest itself in the audio signal way before it starts affecting a motor of the size required for direct drive. And running things from a single socket shouldn’t cause a problem unless your hi-fi is way powerful – a single 13amp socket is capable of over 4KW of power (and if the lamp isn’t occasionally browning out – ie dipping in intensity then returning, then you likely have power to spare on it)

If you don’t find cleaning the bearings and oiling them helps, you could try cleaning the pitch fader (get a decent contact cleaner spray from maplins or such, and spray the fader track to remove any dirt or whatnot that may have built up there)…

that solved my problems when i used to run off turntables