Pico power supply noise

[trumpetman]

Hi all

Discovered that my Pico Power supply has just started to become a little noisy – not bad big stuff but it is very faintly there. It is not a major problem, but I know it won’t cure itself, and if it needs to be sorted then now is best as I fancy a bit of dac auditioning when things crop up here secondhand

Not knowing much about this at all I thought I would ask for some opinions regarding what to do from you guys.

Googling stuff – seems that it can be a fault with them. I don’t use jplay but a google search took me to the jplay forum and I read a thread on using a linear power supply – what? Eh? Help!..... out of my depth already. :nerves:

So do I get it looked at, get something built – looking forward to some suggestions.

Spec is 12v 12.5a and 160w

Cheers

trumpetman

 

[tonerei]

So do I get it looked at, get something built – looking forward to some suggestions.

Spec is 12v 12.5a and 160w

Cheers

trumpetman

Maplin Linear supply will do instead of the smps you are currently using. If you decide to go down that route make sure you measure the output of the maplin with a multimeter and turn it down to 12.5a. It puts out too much for the pico from stock. To adjsut you just remove the cover and using a flat blade screwdriver turn down the screw so the maplin just shows 12.5/7a on multi. Be careful don't touch any thing inside. http://www.firstlightoptics.com/power/maplins-xm21x-7a-138v-regulated-mains-power-supply.html12

Not sure if your problem is just the smps or a dodgy pico

If you get braver buy a 12v motorcycle battery and wire that inline with the linear. Cheap way to get linear and battery supply.

 

[baltika_no_9]

............... turn it down to 12.5a. ................................

======================================================

Turn it down to 12.5a? The PSU your link refers to, ignoring the extraneous "12" at the end of the .html, is a 13.8V 5A continuous/7A surge supply.

http://www.firstlightoptics.com/power/maplins-xm21x-7a-138v-regulated-mains-power-supply.html

The OP is looking for 12.5A at 12V.

 

[tonerei]

............... turn it down to 12.5a. ................................======================================================

Turn it down to 12.5a? The PSU your link refers to, ignoring the extraneous "12" at the end of the .html, is a 13.8V 5A continuous/7A surge supply.

http://www.firstlightoptics.com/power/maplins-xm21x-7a-138v-regulated-mains-power-supply.html

The OP is looking for 12.5A at 12V.

Sorry you are right I was referring to the volts. It can be turned down to 12.5v by lifting the hood and adjusting downwards. If op requires 12.5a this will not do.

Maybe op would confirm that point.

 

[Mikeb]

Check out the Voltcraft Linear (transformer powereed) power supplies at this link http://www.rapidonline.com/Electrical-Power/Voltcraft-Fixed-Voltage-Linear-Power-Supply-Bench-526121 , scroll down the page for higher powered models. I have just bought one for my Asus embedded atom based 1.8ghz 2 core computer for streaming music to my Touch.I use the Voltcraft power supply directly connected to my 120watt Pico power adapter, this unit is from the wide voltage input model range, so all I did was to open up the Voltcraft and turn the pot to the max output voltage of around 15volts which is ok for my Pico unit . The unit was delivered to my door in less than 24hours from order being placed, cost approx £28 for a 6amp (8amp short term) model.

 

[Mikeb]

I should have mentioned these Voltcraft power supplies are the same ones that Itemaudio list e on their site,but they cost almost double the Rapidonline one

 

[trumpetman]

Thanks for replies so far.

I have done some further investigation and I think it might be the either the powerbrick or the way my usb is implementing itself. I've got a cheapo dual conduit kit coming tomorrow (vacdac jobby) and that should help in the elimination of the power supply to the dac.

If you have any ideas that might help I'll be pleased to hear them! It is a faint hissing noise and a click - only audible when nothing playing!

Mikeb and tonerei - the spec of 12v 12.5a and 160w was the spec I read of the powerbrick. I don't really know what wattage I would need, is there a formula say 2w? (amps?) for an x and 5 for a z? The load is to power the motherboard, 8gb ram, ssd, usb dac at the mo, wireless usb module, sometimes a mouse if I am tinkering. To my mind that is not 160w, but if someone could help me calculate things that will be great.

Mikeb was it difficult to make up a power lead? Is the centre pin positive or negative? So many questions sorry

Thanks everyone

 

[tonerei]

I take it you are using a fanless pc low power requirements. Unless you are pumping out huge watts the maplin if and a big if you want to try a cheap linear supply option. Reality is you need to fix your problem first of all. Do you have another pc that you could use the power supply from? Just to check if the SMPS is the problem

Can you disconnect the usb card and use the usb ports on the pc to try and eliminate that?

With regard to substituting a linear unit you have to make sure it is not putting out too many volts that it will fry the pico.

 

[baltika_no_9]

Thanks for replies so far....................is there a formula say 2w? (amps?) for an x and 5 for a z? ...............

Thanks everyone[/color][/size][/font]

The formula for DC (and for rule of thumb calculation for AC) is Watts=Volts x Amps, so 12V at 12.5A = 150W.

Edit...sorry you're looking for a list of consumption by component, apologies. If it helps - I use a 160W pico PSU in my passive set up, 8GB memory as you have, SSD, CPU with a 45W TDP, optical drive and the most I've measured the consumption at is 78W and that was with tests running stressing the 8 CPU threads and the graphics at 100%.

This is the guide I used as a rough and ready estimate of power consumption. In the Power Supply section you'll find a table of typical consumption by component which may be of use. http://www.streacom.com/system-build-guide/

Regards

Edit the SMPS I use is this one http://www.ebay.co.uk/itm/Mini-ITX-Pico-PSU-160XT-160-XT-12V-Mains-UK-Power-Supply-Adapter-/190859770521?pt=UK_ConsumerElectronics_PowerAdaptors_SM&hash=item2c7020fa99

 

[Chumpy]

Safe suitable solutions for all. W=AV etc.

 

[trumpetman]

Safe suitable solutions for all. W=AV etc.

...and to you as well

baltika_no_9 - thanks for the link and the formula, took me back to my physics classes at school

Mikeb - thanks for your input and the pm'd information much appreciated

Quite a bit of the initial noise appears to be sorted, my cheapy dual conduit has made a difference in my system at this time and also moving the power brick well out of the way, so all is looking betterish.

I did a bit of rack housekeeping as well - separating inputs well away from power cables etc

Quite impressed with the m2tech hiface dac - for such a little thing it really performs - looking to do a bit of dac rolling if things come up here now

Cheers

trumpetman

 

[trumpetman]

Just a quick update

Had a long chat with the tech chaps at quietpc today. It seems that they are aware that some FSP power bricks for pico supply units can generate noise in some systems. They have had to exchange some and have also contacted the manufacturer and at the moment there is not a solution - some happy customers and a small handful with noise.

What they did offer was generous - try a different power supply, pico or nano and corresponding power brick on a trial basis, if it makes no difference then full refund - can't be more helpful than that. :^

So at least I know I wasn't hearing things and have been able to narrow things down to an external component.

cheers

trumpetman