Power supply for DAC,

[morglum]

I want to build a media center that will output music from my raspberry pi (using Raspyfi software) to a DAC.

All these parts will be in the same enclosure. All accept 5V.

Raspberry PI (USB)
XMOS (USB to I2S)
DAC (I2S to RCA)

How do you recommend I power them without breaking the bank?
Any suggestion on parts alternative are welcome.

Thanks,
S.

 

[dangus]

Maybe a small open-frame power supply that delivers 5 and 12V; run the Pi and XMOS from the 5V. Use a separate linear regulator to make quieter 5V for the DAC. Maybe even use separate 5V regulators for the analog and digital sections of the DAC. Or, consider whether it's possible to use opamps rum from a higher voltage supply for the output stage.

 

[midyim]

5V Wall wart

The Ioncell wall-wart works well for me. Its tested here...USB Power Supply/Charger Test

 

[morglum]

thanks everyone!

If I get a transformer, should I go for 12VDc or 12VAc (then rectify?)

If I get a 110VAC-12VDC transformer is there any advantage between:
1) Transformer has 1 output, run 1 LM317 to get it down to 5DC, then split in 3 to the 3 devices.
2) Transformer has 1 output, split between 3 LM317 to get it down to 5DC, then connect each LM317 to a device
3) Transformer has 3 output, each goes to a LM317 to get it down to 5DC, then connect each LM317 to a device

The Ioncell wall-wart works well for me. Its tested here...USB Power Supply/Charger Test

Similarly, I already have a 2A 5V wall wart from a smartphone. Can I hack it open an run it parallel to my 3 devices, or is there an advantage to the ioncell's 4 ports?

Finally, I'm considering putting the three devices in the same case an hifimediy's T1 amp and SMPS300R power supply (110VAc-*>39VDC)
Would it be a good/bad idea to take the output from the SMPS300R and split is into 4:
a) 39V into the T1 amp
b) , c) d) into 3 different LM317

Again, is splitting the output into many devices a bad idea? Also 39V-*>5V seems like a lot of a drop.. would I run into heat problems?

 

[morglum]

Maybe a small open-frame power supply that delivers 5 and 12V; run the Pi and XMOS from the 5V. Use a separate linear regulator to make quieter 5V for the DAC. Maybe even use separate 5V regulators for the analog and digital sections of the DAC. Or, consider whether it's possible to use opamps rum from a higher voltage supply for the output stage.

Would this be a good example of what you meant? It's the cheapes 5v/12v I've found on newark canada.

LPT44 - EMERSON NETWORK POWER - PSU, OPEN PCB, 40W, 3 OUTPUT | Newark element14 Canada

Manufacturer: EMERSON NETWORK POWER
Newark Part No.: 96K5433
Manufacturer Part No LPT44

• Technical Data Sheet (171.28KB) EN

Product Information

• Approvals / Standards: (Not Applicable)
• Input Voltage VAC: 85V to 264V
• No. of Outputs: 3
• Output Current Max: 4A, 2A, 500mA
• Output Power Max: 40
• Output Voltage Nom.: 5V, 12V, -12V
• Power Supply Output Type: Adjustable, Fixed
• SVHC: No SVHC (20-Jun-2013)

 

[midyim]

Getting a USB hub would be safer/easier then hacking into the wall-wart. You need to ensure there is sufficient power available for your devices. I have gone through the exercise of .. a] Linear regulators : LM7805/ LT1083-05 from a 12V SLA b] Buck regulators from a 12V SLA c] Boost regulators from paralled LiLons d] Wall-warts My aging ears couldn't hear any difference apart from hum with some wall-warts [probably the danger with mains sources]. Dropping from 39V is going to be a challenge [34W+ @ 1A]

thanks everyone!
Similarly, I already have a 2A 5V wall wart from a smartphone. Can I hack it open an run it parallel to my 3 devices, or is there an advantage to the ioncell's 4 ports?

Finally, I'm considering putting the three devices in the same case an hifimediy's T1 amp and SMPS300R power supply (110VAc-*>39VDC)
Would it be a good/bad idea to take the output from the SMPS300R and split is into 4:
a) 39V into the T1 amp
b) , c) d) into 3 different LM317

Again, is splitting the output into many devices a bad idea? Also 39V-*>5V seems like a lot of a drop.. would I run into heat problems?