Boycie

Origin Live

8 posts in this topic

Hi Chaps,

Some help/advice required please.

Can someone advise me whether there is a cheaper alternative to the £200 upgrade transformer from OL?

I have seen on the web that Maplins do 12volt 3amp power supplies/transformers which are suitable but the link I found isn't recognised any more.

I obviously don't want to get the wrong item and risk damaging the standard motor unit I've got.

Any help would be greatly appreciated.

Cheers All.

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The tranny from Maplins you were looking at will do the job every bit as well as the OL model, been there, done that, owned them both, measured them on the scope, checked the speed digitally by ripping a test track- there's no difference other than 180 sheets from the Bank Of England.

http://www.maplin.co.uk/ac-ac-fixed-voltage-high-current-power-supplies-240

write the part number down they do keep moving these around the website for some reason

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Thanks Simon, that's much appreciated.

However, just one clarification needed please; just put a multimeter onto the wall wart I have and it's putting out 9.6volts ac. Therefore, I take it that the 12volt ac version is the one I require?

Cheers

Boycie.

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No, you require the 9v version. Adjustment of the speed should cover any difference in voltage output. 0.6 volts is well within the variation you might expect from UK mains which can be over 250v and still be within spec. However which version of the PSU do you have? The much celebrated "Advanced" PSU is only half wave rectified (mine is anyway) and there may be mileage from using full wave rectification there. A project I keep meaning to do with mine (together with a bigger smoothing cap). I would be doing that before an oversize transformer.

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No, you require the 9v version. Adjustment of the speed should cover any difference in voltage output. 0.6 volts is well within the variation you might expect from UK mains which can be over 250v and still be within spec. However which version of the PSU do you have? The much celebrated "Advanced" PSU is only half wave rectified (mine is anyway) and there may be mileage from using full wave rectification there. A project I keep meaning to do with mine (together with a bigger smoothing cap). I would be doing that before an oversize transformer.

Bugger, just got the 12v unit so I'll have to change it.

In answer to your question re which PSU I have it's the basic one I'm afraid but even that was leaps and bounds better than the AC motor the turntable started life with. It's based on a Rega Planar 3 but the only thing left is the bearing and sub platter and the RB300 (which is fully Incognito wired).

Thanks for the clarification.

Cheers

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The 12 volt might still be fine there is nothing inside that is rated less than 15volts (the opamp) so there's nothing to blow up, though you might well have to adjust the trimmers a fair bit. If you can't dial them back enough then you will need the lower rated 9v unit. I ran mine on the 12v Maplin supply until `i built my own PSU.

The back EMF from commutation noise from the DC motor is far larger than any noise remaining on the DC rail after it has been through the main reservoir capacitor inside the PSU, so full wave half wave makes no difference. Been there scoped that.

If you are running the advanced PSu and if it's the correct version then you can replace the resistor loaded 'constant current source' for a much more accurate ring of two CCS using two transistors, this will give you much more stable voltage with less drift from inside to outside of an album side. You should bear in mind that despite adverts to the contrary, there was no 'feedback loop' in the OL motor control boards (certainly in the v7 versions) so effectively they are nothing more than basically regulated power supply. To get accurate speed out of an origin Live DC motor you need a power supply from someone else that has built in current sensing and compensation.

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Hi Guys,

Well I've tried the 12volt version and it seems to work fine. Surprisingly I didn't have to change the speed hardly at all and only time will tell how much improvement this mod will give. Initial thoughts are more bass and better timing but more listening required I think.

Thanks very much for all the help and guidance.

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Result. Simon at least wore his thinking cap when answering your question.:oops:

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