System optimizations?

[Mullet]

Besides doing SoX sample rate conversion, which I asked about in another thread, what other software optimizations are recommended for optimal playback?

Thanks,
Mullet

[swizzle]

These are system level modifications, you can break your install, and ymmv on any perceived improvements, etc.

http://archimago.blogspot.com/2017/01/me...b.html?m=1

The mpd settings below may be of interest too, I haven’t tried the other settings but I wouldn’t underclock things that much and don’t know what the various ram settings not included in the archimago post above do.

http://www.diyaudio.com/forums/pc-based/...ost5398891

[Mullet]

Thanks @swizzle for the links. Looking at that Archimago article it looks like he's suggesting that there is no noise introduced by USB output of the Pi. I use a DAC called the Gamma2... https://www.amb.org/audio/gamma2/ via it's USB input. Any incoming signal is up-sampled and re-clocked to 24/96 automatically and I don't hear any discernible noise, etc.

Using top I'm only apparently using 1% with MPD tops. Looks like I can considerably lower the clock speed, etc. to see if it makes for a more euphonic experience.

[Skip Pack]

Thanks @swizzle for the links. Looking at that Archimago article it looks like he's suggesting that there is no noise introduced by USB output of the Pi. I use a DAC called the Gamma2... https://www.amb.org/audio/gamma2/ via it's USB input. Any incoming signal is up-sampled and re-clocked to 24/96 automatically and I don't hear any discernible noise, etc.

Using top I'm only apparently using 1% with MPD tops. Looks like I can considerably lower the clock speed, etc. to see if it makes for a more euphonic experience.

Following the links in swizzle's post, I first did the Archmago CRAAP clock changes via the config.txt edits. That netted a nice improvement for me with my Allo Boss dac. I then did the rest of the changes suggested in the other link (Sinski) without adding the changes he suggests to config.txt. I played a number of songs, but Moode was broken. It would start an album selection on apparently random songs rather than the first song, and would stop at the end of a song but not move to the next. I wasn't surprised that it broke, and I do not expect help here as we are making changes beyond the scope of the most diligent support (which Tim certainly provides).  The single-song-only sound quality was wonderful, so I'll attempt to try these mods very incrementally and zero in on what works and what blows things up.

Skip

[rhizomusicosmos]

Thanks @swizzle for the links. Looking at that Archimago article it looks like he's suggesting that there is no noise introduced by USB output of the Pi. I use a DAC called the Gamma2... https://www.amb.org/audio/gamma2/ via it's USB input. Any incoming signal is up-sampled and re-clocked to 24/96 automatically and I don't hear any discernible noise, etc.

Using top I'm only apparently using 1% with MPD tops. Looks like I can considerably lower the clock speed, etc. to see if it makes for a more euphonic experience.

Following the links in swizzle's post, I first did the Archmago CRAAP clock changes via the config.txt edits. That netted a nice improvement for me with my Allo Boss dac. I then did the rest of the changes suggested in the other link (Sinski) without adding the changes he suggests to config.txt. I played a number of songs, but Moode was broken. It would start an album selection on apparently random songs rather than the first song, and would stop at the end of a song but not move to the next. I wasn't surprised that it broke, and I do not expect help here as we are making changes beyond the scope of the most diligent support (which Tim certainly provides).  The single-song-only sound quality was wonderful, so I'll attempt to try these mods very incrementally and zero in on what works and what blows things up.

Skip

Hi Skip, though I'm not a believer in audio quality benefits from the CRAAP™ settings (and neither is Archimago), I am interested in the power reductions. Do you find any drop in responsiveness when browsing the library while using the underclocking settings?

Thanks,
Richard

[Skip Pack]

Hi Skip, though I'm not a believer in audio quality benefits from the CRAAP™ settings (and neither is Archimago), I am interested in the power reductions. Do you find any drop in responsiveness when browsing the library while using the underclocking settings?

Thanks,
Richard

No drop in responsiveness that I can detect, but I rarely use the library. I'm on the Browse screen or the Playback screen all the time. As far as audio quality, what I pick up is a slight change in tonal balance, reducing the high mids. It's not any sense of reduced distortion, a blacker background or increased clarity. I have 71 year old ears which have steadily become a little more intolerant of "brightness" over the years. So, my definition of sound quality need not align perfectly with other folks.

Similarly, I have tested multiple resolutions and phase settings on upscaling using SoX on files from the command line. You can see the reduction of CPU load while playing versus the same upsampling done on the fly in MPD. I believe I heard a slight "relaxation" comparing the two regimes that tallies with my perceived difference with and without Archmago's settings.

Skip

Skip

[yannig]

tried this optimization.

works well with local USB files.

but Airplay renderer doesn't stand more than severals minutes. 

So, I went back...

[Mullet]

Hi Skip, though I'm not a believer in audio quality benefits from the CRAAP™ settings (and neither is Archimago), I am interested in the power reductions. Do you find any drop in responsiveness when browsing the library while using the underclocking settings?

Thanks,
Richard

I didn't read Archimago's blog post as not being a believer in CRAAP. I think he was being a little hyperbolic in terms of what a typical audiophile believes though. Still it seemed like he was suggesting that there was a difference when he used those settings.

To be clear, I've just applied his settings and I can't confirm I hear much of a difference. It's hard to A/B something like this being that you'd have to restart the Pi after changing settings. Audio memory is so short. That being said, it sounds like his rationale in his settings changes is sound. Are his measurements made pre or post settings changes? I didn't pick up that detail in my reading.

[rhizomusicosmos]

Hi Skip, though I'm not a believer in audio quality benefits from the CRAAP™ settings (and neither is Archimago), I am interested in the power reductions. Do you find any drop in responsiveness when browsing the library while using the underclocking settings?

Thanks,
Richard

I didn't read Archimago's blog post as not being a believer in CRAAP. I think he was being a little hyperbolic in terms of what a typical audiophile believes though. Still it seemed like he was suggesting that there was a difference when he used those settings.

To be clear, I've just applied his settings and I can't confirm I hear much of a difference. It's hard to A/B something like this being that you'd have to restart the Pi after changing settings. Audio memory is so short. That being said, it sounds like his rationale in his settings changes is sound. Are his measurements made pre or post settings changes? I didn't pick up that detail in my reading.

Perhaps you're right. My initial reading was that it was firmly tongue-in-cheek but in re-reading my impression is that he believes it makes sense to reduce the overhead on the RPi as it isn't necessary for audio streaming.

The USB testing seems to have been done pre-CRAAP. In the comments:
Archimago: "The measurements I showed are *stock* Pi 3. None of those are with the CRAAP optimizations. It only gets better with CRAAP... :-)"

I will point out though that he is using PiCorePlayer which may be even less demanding than moOde on resources.

[hifix]

No drop in responsiveness that I can detect, but I rarely use the library. I'm on the Browse screen or the Playback screen all the time. As far as audio quality, what I pick up is a slight change in tonal balance, reducing the high mids. It's not any sense of reduced distortion, a blacker background or increased clarity. I have 71 year old ears which have steadily become a little more intolerant of "brightness" over the years. So, my definition of sound quality need not align perfectly with other folks.

I've found the same with 3.81 - 3.84 with an audiphonics es9023 DAC.