3 ms·

Are you expecting them to add a hi-fi ADC and a mic preamp to a $35 SBC? The existing audio output on the Pi is of terrible quality and I would expect any futur

by opencl 7y ago

Are you expecting them to add a hi-fi ADC and a mic preamp to a $35 SBC? The existing audio output on the Pi is of terrible quality and I would expect any future audio input to be of worse quality than those $10 XLR->USB mic adapters.

squarefoot 7y ago
The Allwinner H2+ and H3 CPUs are used in sub $20 and sub $10 boards such as some Orange and Nano PIs though they seem to be very different beasts sound wise from the Raspberries. From page 61 of the Allwinner H3 CPU data sheet: ------ 2.1.8.1. Audio Codec - Two audio digital-to-analog(DAC) channels - Support analog/ digital volume control - One low-noise analog microphone bias output - Analog low-power loop from line-in /microphone to lineout outputs - Support Dynamic Range Controller adjusting the DAC playback output - Three audio inputs: -Two differential microphone inputs -Stereo Linein input - Two audio analog-to-digital(ADC) channels - 92dB SNR@A-weight - Supports ADC Sample Rates from 8KHz to 48KHz Support Automatic Gain Control(AGC) and Dynamic Range Control(DRC) adjusting the ADC recording input
- makomk 7y ago
  The trouble is, most of the H2/H3 boards seem to be designed as Pi-alikes and don't bother to wire up non-Pi features like line in. I'm not sure they'd even particularly benefit from doing so - not matter how useful the extra features are, all the hobbyist sites frame their discussion of other boards around how well they do the things that the Raspberry Pi can do, so chances are most people will never find out about what those other boards do better.
  - squarefoot 7y ago
    That is true. Although the H2+/3 have a much better line output than the Raspberries and stereo line in plus differential mic in, on most boards the only input available is a mono mic one which is better than nothing, but a real stereo line in could turn out to be really useful. Actually, the mic input shouldn't pose any problems in some aplications, save for possibly higher noise than what could be obtained by pairing a quiet single stage preamp to a line input, however I wish board makers paid more attention to the audio world; with todays faster cores and cheap memory there are some killer apps waiting to happen. As an example, guitarix (http://guitarix.org http://guitarix.org) has been already ported to ARM, so a small board with decent audio i/o would make an ideal candidate for building a very compact guitar fx processor.
mikece 7y ago
I didn't say hi-fi; AC97 would be more than enough. The point is something hardware based that's on the board. I've heard that PIs are frequently used as HTPC machines so terrible audio out, as you put it, is surprising to me.
- kingosticks 7y ago
  Calling it terrible is entirely unfair. It's perfectly usable since the fixes went in a couple of years ago. For most use cases there's no reason to buy an audio HAT any more. Perhaps the poster is using (very) old software? And of course, HTPC users would likely be taking their audio over HDMI anyway.
- somepig 7y ago
  nobody uses analog audio out in an HTPC use case. You send digital audio streams out the HDMI port. Even a low end external ADC is going to greatly outperform anything RPi could ship onboard for a reasonable cost, and even if they did ship something onboard, at this point it would almost certainly just be a USB ADC, but onboard.
  - fulafel 7y ago
    Many people use analog audio because it's good value when you have old amps lying around. Most htpc users aren't audiophiles.

by opencl 7y ago

squarefoot 7y ago

The Allwinner H2+ and H3 CPUs are used in sub $20 and sub $10 boards such as some Orange and Nano PIs though they seem to be very different beasts sound wise from the Raspberries. From page 61 of the Allwinner H3 CPU data sheet: ------ 2.1.8.1. Audio Codec - Two audio digital-to-analog(DAC) channels - Support analog/ digital volume control - One low-noise analog microphone bias output - Analog low-power loop from line-in /microphone to lineout outputs - Support Dynamic Range Controller adjusting the DAC playback output - Three audio inputs: -Two differential microphone inputs -Stereo Linein input - Two audio analog-to-digital(ADC) channels - 92dB SNR@A-weight - Supports ADC Sample Rates from 8KHz to 48KHz Support Automatic Gain Control(AGC) and Dynamic Range Control(DRC) adjusting the ADC recording input

makomk 7y ago
The trouble is, most of the H2/H3 boards seem to be designed as Pi-alikes and don't bother to wire up non-Pi features like line in. I'm not sure they'd even particularly benefit from doing so - not matter how useful the extra features are, all the hobbyist sites frame their discussion of other boards around how well they do the things that the Raspberry Pi can do, so chances are most people will never find out about what those other boards do better.
- squarefoot 7y ago
  That is true. Although the H2+/3 have a much better line output than the Raspberries and stereo line in plus differential mic in, on most boards the only input available is a mono mic one which is better than nothing, but a real stereo line in could turn out to be really useful. Actually, the mic input shouldn't pose any problems in some aplications, save for possibly higher noise than what could be obtained by pairing a quiet single stage preamp to a line input, however I wish board makers paid more attention to the audio world; with todays faster cores and cheap memory there are some killer apps waiting to happen. As an example, guitarix (http://guitarix.org http://guitarix.org) has been already ported to ARM, so a small board with decent audio i/o would make an ideal candidate for building a very compact guitar fx processor.

mikece 7y ago

I didn't say hi-fi; AC97 would be more than enough. The point is something hardware based that's on the board. I've heard that PIs are frequently used as HTPC machines so terrible audio out, as you put it, is surprising to me.

kingosticks 7y ago
Calling it terrible is entirely unfair. It's perfectly usable since the fixes went in a couple of years ago. For most use cases there's no reason to buy an audio HAT any more. Perhaps the poster is using (very) old software? And of course, HTPC users would likely be taking their audio over HDMI anyway.
somepig 7y ago
nobody uses analog audio out in an HTPC use case. You send digital audio streams out the HDMI port. Even a low end external ADC is going to greatly outperform anything RPi could ship onboard for a reasonable cost, and even if they did ship something onboard, at this point it would almost certainly just be a USB ADC, but onboard.
- fulafel 7y ago
  Many people use analog audio because it's good value when you have old amps lying around. Most htpc users aren't audiophiles.