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Budget Standalone "Toslink > DSP > Toslink" with Camilladsp. Set up instructions for newbies.

mdsimon2

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Ah okay, thought so.
btw found this upsampler, might be a better option then MCHStreamer. what do you think?

That is a hardware ASRC, if you had that between your source and your RPi it could convert all inputs to a common sample rate. You could then run CamillaDSP at a constant sample rate.

Michael
 

m_u

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That is a hardware ASRC, if you had that between your source and your RPi it could convert all inputs to a common sample rate. You could then run CamillaDSP at a constant sample rate.

Michael
yes, and it accepts coaxial which is fine. And I guess I can hook it up via i2s to raspberry (although I have to dump my transport hat as there is only one i2s line and use something like usb to tosslink)
As a cheaper alternative DIR9001 + SRC4192I might work but I'm not a DIY expert.
Or even this thing which looks like it does everything all in one
The latter looks more appealing though
 
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Rafaille

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:eek: this can be a better deal than the 1eur hdmi extractor. Will try to get one, thanks!
48/16 still perfectly fits TV usage
Any (audible) reason why 48/16 would not be enough for music?
 
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MCH

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Any (audible) reason why 48/16 would not be enough for music?
not that i know of, i believe camilladsp will still use a higher bit depth for processing -i might be wrong though-. I said perfect for TV usage because TVs typically send 48kHz/16 bit via toslink
 

Rafaille

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not that i know of, i believe camilladsp will still use a higher bit depth for processing -i might be wrong though-. I said perfect for TV usage because TVs typically send 48kHz/16 bit via toslink
Cdsp appears to process at float64 internally indeed.
Regarding sample rate, I just found this post from Michael about 48 vs 96 kHz, probably inaudible, I mean I just trust the guy :) and the slight extra warping at high freqs means my own ears will be the limiting factor anyway.
 
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mdsimon2

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Biggest issue to me is 16 bit output will have a lot of residual noise unless you have an analog volume control. Assuming you are using a DAC with 2 V output, residual noise at the DAC output will be 30 uV, which will then be multiplied by amplifier gain.

A big advantage of 24 or 32 bit output to the DAC is that at lower levels digital volume control will attenuate the noise from your source and push it below the noise floor of your DAC + amplifier.

For example, take a 16 bit source and 32 bit output to the DAC. If you have a DAC with 112 dB dynamic range at 2 V output, coupled with an amplifier that has 100 dB dynamic range at 5 W in to 4 ohm and 25.6 dB gain, at -20 dB digital volume control position residual noise at the speaker terminals is 121 uV which is pretty good.

If you only have 16 bit output to DAC with the same system residual noise at the speaker terminals will be 591 uV at digital all volume control levels. In this system a lower noise DAC or amplifier would gain you almost nothing.

Michael
 

Rafaille

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Biggest issue to me is 16 bit output will have a lot of residual noise unless you have an analog volume control. Assuming you are using a DAC with 2 V output, residual noise at the DAC output will be 30 uV, which will then be multiplied by amplifier gain.

A big advantage of 24 or 32 bit output to the DAC is that at lower levels digital volume control will attenuate the noise from your source and push it below the noise floor of your DAC + amplifier.

For example, take a 16 bit source and 32 bit output to the DAC. If you have a DAC with 112 dB dynamic range at 2 V output, coupled with an amplifier that has 100 dB dynamic range at 5 W in to 4 ohm and 25.6 dB gain, at -20 dB digital volume control position residual noise at the speaker terminals is 121 uV which is pretty good.

If you only have 16 bit output to DAC with the same system residual noise at the speaker terminals will be 591 uV at digital all volume control levels. In this system a lower noise DAC or amplifier would gain you almost nothing.

Michael
Thank you very much for the detailed explanation Michael, that makes a lot of sense. As I do not have an analog volume control in my current setup, it is very relevant to me.

I have been looking for cheap-ish or second hand sound card that would do spdif output (for speakers through decent dac) + analog output (for subwoofer), in the 24/32 bit realm but I have not found much.

Only contendant so far is Sound Blaster Extigy at £32 used on ebay, lots of I/O and seems to work well in linux. Anyone tried that?
 

Rafaille

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As an alternative I suppose I could use two of these usb -> spdif and a spare cheap dac for the sub.
I am assuming the spdif from both units will be clock synced?
 

melomane13

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Any (audible) reason why 48/16 would not be enough for music?
i use terratec aureon 7.1 usb . 16bit 48khz (Cmedia CM6206) . Spdif in and out, 8 channels , buffer for headphones.
with my setup , digital volume with camillaDSP , JBL studio 590 ( 92 db / W) and aiyama A07 amp i can hear very little noise at 10 cm from horn.
if i use another soundcard i have ( TerraTec Aureon XFire HD 8.0 USB, 24 bit with 105 snr) this is dead silent.
But i dont hear at 10cm...
so using best soundcard change nothing in real use. 16/44.1(48) is all that is needed.
 
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Rafaille

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i use terratec aureon 7.1 usb . 16bit 48khz (Cmedia CM6206) . Spdif in and out, 8 channels , buffer for headphones.
with my setup , digital volume with camillaDSP , JBL studio 590 ( 92 db / W) and aiyama A07 amp i can hear very little noise at 10 cm from horn.
if i use another soundcard i have ( TerraTec Aureon XFire HD 8.0 USB, 24 bit with 105 snr) this is dead silent.
But i dont hear at 10cm...
so using best soundcard change nothing in real use. 16/44.1(48) is all that is needed.
Thanks for the feedback, much appreciated.
I hear you and that was my feeling as well based on other people IRL experience.

However, we are constantly chasing low noise kits across the chain with good dacs and amps so I also feel that it would be a shame to 'waste' it because I was a bit cheap.

It seems that I could get away with it by investing a tiny bit more on either a higher bit depth processing sound card or 2x usb-spdif converters and recycling a spare dac.
 
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