Quiet sound, What Amp to use?

Austen posted Mar 15 '20, 22:53:

I have a pi 3B and I was planning on using the the 3.5mm audio and plugging it into a little drok 5w amp, but the audio level from the pi is so quiet that the drok amp barely makes a sound through the speakers (speaker and amp setup works great with a regular audio input from a phone etc..). The pi audio level is at its highest so that my -6b piano samples don't clip. I am hoping to put it all in a box with little speakers for personal playing. Currently I can only use it with my Roland amp. I am a noob with audio... any recommendations for what to do to get a louder signal to my drok 5w speaker amp?

Austen posted Mar 15 '20, 23:16:

Also I have read through Hans' [Controlling Volume]() and want to know if a cheap DAC would be the solution? Also if you're reading this Hans, where can I tip you a beer? Thanks

Austen posted Mar 15 '20, 23:25:

I am going to try the tips in #Crackly distortion when I play multiple notes?

Austen posted Mar 16 '20, 00:13:

So I have set my %gain=0.75 in the definition.txt for the "normalized GrandPiano" (my favorite for playing) and then I have the alsamixer set to 84 and I get the max volume out of the 3.5mm without popping and clipping.

I see I can add an alsamixer line in the config.txt but I am not sure how to format it. Any help their @HansEhv ?

Austen posted Mar 16 '20, 02:01:

This is still not enough output though to use the drok amp speaker setup. I would say the output of the pi is currently about 1/4 the loudness of a phones output at max. Sounds great on my roland amp though!

Austen posted Mar 16 '20, 02:22:

Would the PCM2704 USB DAC allow me to get a louder output for the drok amp?

HansEhv posted Mar 20 '20, 01:28:

Hi Austen,
Always in for a beer :-)
Next info only applies to the homspace (=my) version of samplerbox....
The alsa mixer config parameter is obsoleted or will be (don't know exactly what release you're using).
It isn't that crucial for your purpose as it just indicates whether the dac can have it's volume set via software=samplerbox. So the configuration value can be True or False. I thought my last image already sensed it and ignores that parameter, coming image certainly does sense it (amongst other hard to configure values regarding the DAC, you can configure autodetect).
If the value =False, samplerbox assumes 100% which is in line of alsa behaviour. Actual outputvalue always depends on a possible hardware knob on the dac - no way to control (= see or adapt) such "real things" from software in a consistent way.

A cheap dac (just a few euros/dollars) can save you a lot of theoretical thinking. They may malfunction or break later but I found them useful to understand behaviour of other hardware.
As for your drok, this surprises me as it seems a quality device. Perhaps you can configure a default startup somehow. High quality dacs tend to be able to output more than others. I use a HiFiBerry which can be set to 100% without issue resulting into a volume perfectly in range of a PA/stage mixer.

To get a good comparison, you can set (%)%velmode to "sample" to avoid velocity influence of your keyboard / own way of playing (humans tend to play on half of the velocity range).

Hope this helps, Hans


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