Max volume hifiberry amp+

[deef]

I got a rpi2 with a hifiberry amp+ hat I got hardware volume to work. Only problem is if I by accident turn the volume to 100% it's VERY loud and distorted.

Can I somehow set a max volume which are in the tolerate range and won't kill my system heart and ears. So when I crank it to max in the runeaudio UI it's not really max but a fixed value by my choice.

Hope my question is clear enough, thanks!

[PeteB]

You are not the only one to notice this, but I do not think there is a solution yet, at least not when last discussed.

In the meantime, you can set a control in amixer, from the command line, to reduce the output by 6 db. This is a function of the DAC chip, and independent of the RuneAudio software. This will reduce the maximum output of the DAC and prevent distortion at 100%, but not excessively loud output.

You can display all the amixer controls by just typing "amixer" from terminal.

Example to set the output max to -6db:

Code: Select all

[root@runeaudio ~]# amixer sset Analogue 0
Simple mixer control 'Analogue',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 1
  Mono:
  Front Left: Playback 0 [0%] [-6.00dB]
  Front Right: Playback 0 [0%] [-6.00dB]


[dunghnguyen]

alsamixer

[deef]

I'm not totally sure how to do that? Can you be a bit more precise?

[TommyBoy]

how about change two resistors on the amplifier board ?
so 100% is now 5W and not 25watt
this way you also improve signal to noise floor
ask the berry folks about what resistor to modify.

[deef]

I'd rather not physically change the board.

[PeteB]

I'm not totally sure how to do that? Can you be a bit more precise?

Not sure which post you are asking about.

What I meant was, from a terminal window, and from the command line, you can use the following command to scale the DAC chip output down, -6db. The first line above was the command:

Code: Select all

amixer sset Analogue 0

The next few lines were the output.

I think dunghnguyen was giving you another method, using alsamixer. May be easier (?) not sure.

In either case the result is the same, you scale the output down by half.

Beyond that, Frank would have to tell us if the max limit is the same for DAC+ and AMP+, or different.

[dunghnguyen]

Yes @PeteB, if logging in by user 'root' with password of 'rune' then simply typing:

alsamixer

then we cud adjust the original volume.