Re: [fluid-dev] Fluidsynth make strange sounds with ALSA

[Carlo Bramini]

Hello,
actually, Allwinner MCUs are known to have a very good audio codec for their 
class of devices (something between 90dB and 100dB) and they are also known to 
be powerful enough for running softwares like Pianoteq 6, so it is a bit 
strange that you are not able to run Fluidsynth.

However, since I have also built a MIDI digital controller, this looks an 
interesting topic, so I'm wondering if:
1) you got noise/corrupted sound also when playing simple MIDI files.
2) you are getting the sound defects only when you are using Fluidsynth with 
your Arduino based MIDI controller.

I'm also wondering if you put AT LEAST a passive cooling unit on top of the CPU 
of your board. I have not an Orange Pi, but with Raspberry Pi 3 the temperature 
can rise a lot and quickly when the required computations increase, even up to 
85+ celsius degrees, and when this happens you get exactly those defects during 
the sound playback.

Sincerely.


> Il 14 dicembre 2017 alle 17.48 Ceresa Jean-Jacques <address@hidden> ha 
> scritto:
> 
> Hi.
> 
> >For example, the Orange Pi boards mostly (or all?) use Allwinner SoCs which 
> >all come with a good quality DAC.
> 
> Very good news, thanks very much for pointed that.
> 
> cheers
> 
> > > Message du 14/12/17 07:41
> > > De : "Marcus Weseloh" <address@hidden>
> > > A : "Ceresa Jean-Jacques" <address@hidden>, "FluidSynth mailing list" 
> > > <address@hidden>
> > > Copie à : 
> > > Objet : Re: [fluid-dev] Fluidsynth make strange sounds with ALSA
> > > 
> > >
> > 
> > >
> > 
> > >
> > Am 14.12.2017 01:05 schrieb "Ceresa Jean-Jacques" <address@hidden>:
> > > > On this type of hardware (Orange Pi pc or RPi 2,...), the audio (on 
> > > > jack 3.5) is a PWM signal (very low quality signal and very noisy) and 
> > > > the audio driver doesn't work very well for low latency.
> > 
> > That is true for the RPi, but not for the general case. For example, the 
> > Orange Pi boards mostly (or all?) use Allwinner SoCs which all come with a 
> > good quality DAC and headphone amp on chip. And the mainline driver for 
> > those chips is very good and definitely capable of low-latency output.
> > 
> > >
> > Cheers,
> > Marcus
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