Linear PSU for Raspberry Pi 3, which one? Confused.

[dtaylo3]

Thank you for your replay and information. Much appreciated. I have a Asus Tinkerboard running Volumio. Asus states for power supply:

-- "1 x Micro USB cable and a 5V/2~2.5A USB power adapter with LPS marking"

I have read on a number of web sites to make sure you meet the 2.5A number.

The power supply unit at GlassWare I am looking at states:

H-PS-1
The H-PS-1 is a simple low-voltage regulator. You need only hook up a power transformer and the H-PS-1 will rectify and regulate the AC voltage into smooth, stable DC. This little regulator can put out up to 2.5A and it can deliver an output voltage that ranges from +5V to +25V. This power supply is perfect for the 24V Aikido line/headphone amplifier, tube heaters, and Squeezebox PS upgrades.

So I am thinking 25 or 30 VA based on you input.

 

[ktham]

Choose the Glassware LV Regulator instead of the H-P-S1. Details of the LV Regulator are covered in earlier posts. All my Rpi builds with HAT DACs use the LV Regulator. If you are a tweaker you can increase the specified maximum current of 2 Amps.

 

[dtaylo3]

Wow, thanks for the input. My Tinker Board sounds pretty damn good with the wall wart, but an addicted DIYer can resist to check out the alternative.

 

[linuxfan]

I have read on a number of web sites to make sure you meet the 2.5A number.

Yes, also the Raspberry Pi Foundation specifies a 2.5A power supply, but I think this assumes that 99.9% of users will have a small, and possibly cheap SMPS, and these may be dangerous if run above (or just near) their current limit. I think they simply want their customers to have plenty of headroom. Also the higher rating would be needed to deal with any power-hungry USB peripherals that people might plug into their Tinker Board or Pi.

Well I just looked up the current draw of the Asus Tinker Board - 1 amp maximum, so just a little higher than the rPi. And likely to be much lower when used just for normal audio playback.

So I am thinking 25 or 30 VA based on you input.

Yes, drtebi's Triad VPP16-1900 is a good choice, but if you have the space, it wouldn't hurt to go a size up - around 50VA.
And of course drtebi's transformer requires mounting on a circuit board, it may be more convenient to use a chassis-mount transformer;
tham recommends Hammond transformers - 266L16 (35VA) or 266M16 (48VA)
I like this Triad dual bobbin transformer - VPS16-2700 (43VA)
Item # VPS16-2700, Chassis Mount Quick-Connect World Series™ Power Transformers On Triad Magnetics

 

[dtaylo3]

Thanks. I was looking at the Hammond 266L16 last night. Of course GlassAudio is out of stock right now on the supply board. But I am in no rush.

 

[rruffin]

This is just my experience. I have a very revealing system and top tier. Using a good linear supply has improved both raspi and digi one. Ive tested all switching, bad. The powerbank is 2nd best but the linear is best.
Btw raspi+digi one with li esr aupply is the best transport ive ever heard. Better than my Cec transport, better than any Mac audirvana , better than aerender server that i ABed yes, true. And better than the hifiberry pro+.

You can use Audirvana in network mode to upsample and add audio filters to customize the audio file that will be sent to the streamer (DigiOne), getting the best of both worlds - customization of sound and a small quiet computer sending it to the dac.

 

[edbarx]

My intention of posting here is to break a very weak ground loop between Raspberry Pi 3B+ with an IQAudIO DAC PRO hat.

The Raspberry Pi 3B+ is powered from a Pi switching power supply which does not have an earth electrode. I am attributing the hum/buzz to using a switching power supply. The switching power supply still has to rectify and smooth the incoming mains voltage, so a hum/buzz is present in its DC power source. This means, the DC high voltage chopper sees a hum/buzz. Does some of this hum/buzz end up superposed on the SMPS output?

Help is appreciated.

 

[edbarx]

I confirmed the Pi's switching power supply is not the cause of the hum/buzz issue. Trying another amplifier with full volume and but no signal did not result in any audible hum/buzz. The issue is clearly with the other amplifier.

Please, ignore the previous post.