External 5v supply instructions missing in user manual?

Hi,

I am making the assumption that one can power the audio card AND the Pi from the Aux 5V jack, thus avoiding the need for TWO power supplies.

Just tried to use the Wolfson audio card with external 5V supply (5v Aux), so I can try the integrated speaker amplifiers.

It will not work without adding a link or 0 ohm resistor R44, located by the side of the 5v jack socket. without this link, the aux 5v does NOT feed the internal 3.3 and 1.8 v regs.

(see schematic diagrams..... R44 is marked as DNP do not populate, )

The user manual states that one has to add terminations for the speaker cables and also

 It is necessary to supply auxiliary power to the Audio Card in order to drive
external loudspeakers. An external power supply with output voltage of 5V,
current delivery capability of 2,000mA, a centre positive power plug of internal
diameter 2.1mm, and external diameter 5.5mm.

But there is nothing about inserting 0 ohm or link in R44

SHOULD THERE BE?

Also, adding a link to R44 position is not for the inexperienced solderer! It's a 0603 size component.

regards

Patrick

Message was edited by: Patrick Keane

0 superpat over 11 years ago

Hi,

Re-reading my last post I realised I had not fully stated the result of connecting R44 and the 5v Aux

So,,,,, I made a solder bridge on the Audio card at R44 position, couldn't find a 0 ohm SMD in my parts box.

Stuck a 5v jack in the Audio card socket, with NO other PI connected power supply.

It all works well, Pi boots and ausio works great, i.e. running MPD and playing flacs onto line out.

I have not tried the loudspeaker outputs yet, I have to find a pair of small speakers in my junk box. I have a pair of Warfdale bookshelf speakers to hand but they are marked 75W, I don't think a 1.4 W o/p will drive them very well!

cheers

Patrick
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0 richardbeattie over 7 years ago in reply to superpat

Hi,

I am also looking at getting the aux power to power the Raspberry Pi. I am just wondering would you have a schematic diagram of where exactly you put the solder bridge, I am inexperienced at this and so was able to see from your post where the bridge/resistor is meant to go

Thanks,
Richard
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0 clem57 over 6 years ago in reply to richardbeattie

I am going with a USB speaker and avoid the mess. Not digital, but who needs that.
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0 marcelheijkoop over 5 years ago in reply to superpat

Hi,

I have the newer version of the card ( CLAC ) and I use it to drive my speakers daily.
Power is not everything, good effective speakers can work with low power amps.
I assume your card is the same for the amp part, so should use the external 5 volts, and no power connected to the pi.
If I remember correct (years since I read the specs ) the older card had no direct speaker output.
Perhaps that is in line with the DNP remark for your R44.

regards M-H
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