updating database and my pops disapear

dvpaassen

Hello.

First i'd like to compliment you on your good work.
I've been looking at this ever since it was called raspify
and when i got my hands on a raspberry pi I took a shot.

I've got a HiFimeDIY Sabre Tiny USB DAC, Digital to Audio Converter and
when I use it with rune audio it makes noises and when I tried the new usb driver
the noise increases.
But now comes the funny part it plays flawless when i update my database
(files are on a nas (actually another Pi). via Samba.)

notice this is regardless of the bitrate of the files so highres flac makes the
same noise as 320 mp3.

this does also occur with airplay.

my question is does anybody have a clue on how to get it work right?

grtz
Dennis

ACX

Hi dvpaassen, let me understand: the noise completely disappears during the database update process? (with the icon spinning in the RuneUI?)

dvpaassen

Hello ACX,

After aplying the new firmware with new usb driver, the noise is there and it seems to disapear when
I'm updating the Database.
The same thing is happening with volumio.

When I find the time, I will try and reproduce it tonight and see at what point the audio gets destorted and
what makes it go away.

Thank you for your reply.

Dennis

monochrome

Ok I know this is a well thrashed out topic but I solved all my pops and clicks etc by building a new power supply for my Pi - actually technically it's a DC to DC converter.

The argument goes to and fro regarding voltage drop when utilising cheap power supplies and or cables.
I simply wanted to make certain that the Pi was getting the voltage that it should be, regardless of what exactly was at fault, and it wasn't.

From a 5V known brand supply, I was outputting 4.8V and the Pi, when measured across TP1 and TP2 , was seeing 4.3~4.45V.

I don't need to elaborate here as we all know that this is simply not enough voltage for reliable operation.

My Pi is only running a wireless network adapter.
That's it.
Not even a DAC.
For testing, I'm just running analog audio to a set of Logitech 2.1speakers.

I tuned the PSU so that the Pi is now seeing 4.8~4.9V from an input of 5.54V (depending on what it's doing - i.e. whether it's playing audio or not and whether it's high bit-rate or not).
The sound is clean - surprisingly so.
It's certainly no match for a decent DAC, but I have no complaints about the analog quality now.

Incidentally, my Pi is drawing max 480mA at 4.89V.

Apologies for the long winded post - likewise if this in the wrong section but I felt it was pertinent.

If anyone is interested, the figures are:
Output Voltage from plug-pack 8.9V (9V/2A plug-pack)
Output Voltage (from PSU) 5.6V (unloaded), 5.54V (loaded)
Input Voltage (TP1-TP2) 4.8~4.9V
Current Draw 480mA
Dissipation (calculated: Vinput - Voutput*load) = 8.9-5.6*.48 =1.58W or 1.61W under load (so the regulator needs heatsinking).

As the regulator is adjustable I can fine tune the output voltage, and here's where it gets interesting.
Plug headphones in at 4.3~4.4V with nothing playing, and you hear an awful lot of noise consisting of pops, clicks, hum and buzz - particularly during network activity.
Slowly bring the voltage up and the noise disappears at around 4.6 to 4.7V (minimum operating voltage we want to see is 4.75V).
No more noise from the network either.
Clean audio, no pops, clicks or anything - even when the fridge compressor turns on (gasp!)

Ok, again - sorry for the long post but that's my $0.02 worth and it may pay to do your own testing.
Cheers

ACX

monochrome wroteOk I know this is a well thrashed out topic but I solved all my pops and clicks etc by building a new power supply for my Pi - actually technically it's a DC to DC converter.

It would be nice if you could share it with some pics in the DIY and tweaks forum section. I'm also going to share the 5V PSU assembly I did some days ago when I have some time.

dvpaassen

Thanks for the tip on the voltage suply, although I don't think that was the problem here, I do think it might
bring a better performance on the Pi.

About the pops and clicks.
I did a full reinstall. and just did a pacman -Syu to update the kernel and mpd.
I did not do the rpi-update to the next-branch (which i did last time)
and i did the usb hid unbind thing.
Now it plays almost flawless. some hickups while playing FLACs
but not that much.

So thank you for your time, and keep up the good work.

many thanks
Dennis

monochrome

Sure thing ACX, as soon as I get a chance I'll write something up.
many thanks for all your work guys.
Cheers