Carpenter and wannabe hifi expert here, from the UK. Apologies for any newbie mistakes in my questions, but here goes:
I would like to build a digital system consisting of the following:
1) linear power supply to power both a...
2) ...streamer (probably raspberry pi based) and...
3) ...DAC (medium output power - enough for floorstanding speakers, not too loud)
The functionality of the power supply would be along the lines of the Allo Shanti. I would like to keep this simple and have two power outputs each at +5V and 3A max, say.
Having reviewed forums here I have decided to go for the following power supply components:
a) toroidal transformer
I am looking at something along the lines of this one with the following specs:
Any recommendations for specific transformers?
b) ready made pcb board
I would like the output voltage to be regulated by LDOs down to 5V, from whatever gets to them. This is where my technical naivety shows, so apologies for that. Why do I want this? Well, it was recommended elsewhere on this forum. Any recommendations for this board design? I will buy all the components separately. Alternatively, any ready-made high quality board recommendations would also be apreciated!
Thanks!
I would like to build a digital system consisting of the following:
1) linear power supply to power both a...
2) ...streamer (probably raspberry pi based) and...
3) ...DAC (medium output power - enough for floorstanding speakers, not too loud)
The functionality of the power supply would be along the lines of the Allo Shanti. I would like to keep this simple and have two power outputs each at +5V and 3A max, say.
Having reviewed forums here I have decided to go for the following power supply components:
a) toroidal transformer
I am looking at something along the lines of this one with the following specs:
- 30VA (Is this overkill given I probably would not need more than total of 4A at 5V output? Should I go higher? Is 15VA enough, as this seems to be the standard lower size?)
- 2 x 6V secondary voltages (Should I go for 7V, bearing in mind I want to use 5V LDOs, as per below?). I quite like the idea to have dual secondary windings and have two identical output pcb boards, connecting indepedently to the transformer. Is this a good idea and what may be better alternatives?
Any recommendations for specific transformers?
b) ready made pcb board
I would like the output voltage to be regulated by LDOs down to 5V, from whatever gets to them. This is where my technical naivety shows, so apologies for that. Why do I want this? Well, it was recommended elsewhere on this forum. Any recommendations for this board design? I will buy all the components separately. Alternatively, any ready-made high quality board recommendations would also be apreciated!
Thanks!
Sala’s L adapter works pretty well for raspberry pi boards, they pull quite a bit of current. You should use the same for the dac or one of tea bags other power supplies.
https://www.diyaudio.com/community/threads/gb-for-salas-l-adapter-board.338109/latest
https://www.diyaudio.com/community/threads/gb-for-salas-l-adapter-board.338109/latest
30VA is likely under-specified if you're following your trafo with linear regulators delivering 20W sustained. You might just get away with it though if you used a buck reg after the trafo to improve the efficiency of the linear regs.
You mention in 3) that your DAC has 'medium output power' so does that mean its actually a DAC-amp? If you're integrating all components (streamer, DAC and amp) to be fed from a single supply then I can't see any advantage in making your PSU a linear one, it'd be cheaper and more efficient to use a switcher.
You mention in 3) that your DAC has 'medium output power' so does that mean its actually a DAC-amp? If you're integrating all components (streamer, DAC and amp) to be fed from a single supply then I can't see any advantage in making your PSU a linear one, it'd be cheaper and more efficient to use a switcher.
I also want to point out that specifying and building the supply before you have the rest of the system clearly defined has a very high probablity that you need to modify or replace the supply afterwards.
Carts before horses.
Jan
Carts before horses.
Jan