Audiophile options for a HQ external USB DAC

C

cartesius23

Guys, I'm quite new to the FreeBSD world but amazed so far. Please, out of curiosity, you guys who use USB DACs could you share ideas and/or sysctl.conf how to tweak the audio system for highest possible quality. Things regarding bitperfect and such. Thank you!

This is all I currently got:

Code: 
# Sound
hw.snd.verbose=2
hw.snd.default_unit=6
hw.snd.feeder_rate_quality=3
dev.pcm.6.play.vchanformat=s32le:2.0
 
I have:

hw.snd.feeder_rate_quality=4
##To reduce number of sound generated interrupts
hw.snd.latency=7

See also man.sound (the manpage for sound). Lots of useful information
 
The plain and simple, also ugly truth is that you don't need an USB DAC normally, because the DACs which are put on mainboards are more than capable of doing their job nowadays.

Only reasons where it is desireable to get one is this:

1. if the audio coming from mainboard is pestered with hisses and interferences, which you cannot get rid of.
2. if you have got a high impedance set of headphones, like 600 Ohms, while your audio output only can handle let's say 32, which means that volume becomes a problem. Which is not a DAC issue anyway strictly, but of amplification.

It's way more effective to invest the money, which you would use for a DAC for, into your headphones.
 
hardworkingnewbie said:
It's way more effective to invest the money, which you would use for a DAC for, into your headphones.
Click to expand...
Luckily/unfortunately I got both: HQ higher impedance (>= 250-300 Ohm) headphones, so using the USB DAC with integrated amplifier. Currently Fulla Shiit 3 DAC. But I agree that for cheaper headphones it's a waste of money.
 
Yes.
I just use low latency (0) and bitperfect in sysctl.conf.

It's connected to t-400 poweramp which in turn drives a pair of Infinity EL-40 bass reflex speakers.
The sound on FreeBSD is really good.
 
angry_vincent said:
does it work in bitperfect mode? if this mode of any interest. i considering in some future times motu m2 interface but it happens to be not working in bitperfect.
Click to expand...
I used the Focusrite Scarlett on Freebsd 12 and 13 to feed my Drop 789 headphone amp and it worked perfectly in bit-perfect mode. I recently replaced it with a Topping E30 II (price to performance, you can't beat it) and it works perfectly too. I had a Topping D10s for a couple weeks before exchange it for the E30 II and it worked perfectly as well. I've never had issue with my external USB DAC's on Linux or FreeBSD.
 
i had only Shiit Fulla 2 usb dac and it does not work in bit-perfect mode, only distorted sound. It is claimed that this device has full USB protocol support but still no go. It works fine in usual way. Now i am in research of devices that do work in bit-perfect mode.
 
/etc/sysctl.conf

dev.pcm.0.bitperfect=1
dev.pcm.1.bitperfect=1
kern.timecounter.alloweddeviation=0
hw.snd.maxautovchans=0
hw.snd.latency=0

You have to adjust the first two lines according to the channel your music is played on.
For example, it can also be dev.pcm.3.bitperfect=1 depending on your system.

You don't need an USB DAC for perfect sound with these settings.
All you need is an analog connection that is available on almost every motherboard:

By that I mean that if you have a decent motherboard and my settings you achieve a sound quality on the analog connection that can hardly be better.
Analog has the potential to scale the best of all options at 24-bit 96 kHz.

I recommend cmus as a music player with the following settings:
softvol true
softvol_state 100 100

That's all important and to me gives the best quality possible on FreeBSD.
 
Yes, i tried mentioned tunables before and it still did not work. all i had is distorted sound. removing dev.pcm.%d.bitperfect=1 makes it sound normally. with the rest of tunables kept as in example
 
angry_vincent said:
makes it sound normally
Click to expand...
Do you mean the analog connection or the USB DAC?
My settings are for an analog connection.
You will have perfect quality that can no longer be significantly improved via the green analog jack.
What is your playback device? (/dev/dsp0, /dev/dsp1, /dev/dsp2, /dev/dsp3, /dev/dsp4, ..)
 
i no longer have that usb dac ( Shiit Fulla 2 ), i was referring only to this device in all my posts. i tried almost all possible settings and it did not work. currently i have onboard sound in notebook.
 
angry_vincent said:
i no longer have that usb dac ( Shiit Fulla 2 ), i was referring only to this device in all my posts. i tried almost all possible settings and it did not work. currently i have onboard sound in notebook.
Click to expand...
You can run the following command in a terminal: sysctl dev.pcm

Could you please take a screenshot of the full output of this command?
 
dev.pcm.0.mode: 7
dev.pcm.0.bitperfect: 0
dev.pcm.0.buffersize: 65536
dev.pcm.0.rec.vchans: 0
dev.pcm.0.rec.autosrc: 2
dev.pcm.0.rec.32bit: 24
dev.pcm.0.play.vchanformat: s16le:2.0
dev.pcm.0.play.vchanrate: 48000
dev.pcm.0.play.vchanmode: fixed
dev.pcm.0.play.vchans: 1
dev.pcm.0.play.32bit: 24
dev.pcm.0.%parent: hdaa0
dev.pcm.0.%pnpinfo:
dev.pcm.0.%location: nid=31,25,35,27
dev.pcm.0.%driver: pcm
dev.pcm.0.%desc: Conexant CX20590 (Analog 2.0+HP/2.0)
dev.pcm.%parent:
 
Ok.
I'm not sure if that %d in dev.pcm.%d.bitperfect=1 is the right method.
Just to be sure, add the following settings and remove all your other audio settings from this file:

/etc/sysctl.conf

dev.pcm.0.bitperfect=1
kern.timecounter.alloweddeviation=0
hw.snd.maxautovchans=0
hw.snd.latency=0
 
i guess we lost in conversation, %d is just number holder for devices, in your example ( pot #13 ) they are 0 and 1, is why i i have typed generic %d as example., in real situation i use 0 in my case ( just like your example in #19 ). it does not work ( notice it is just notebook oboard sound )
 
angry_vincent said:
i guess we lost in conversation, %d is just number holder for devices, in your example ( pot #13 ) they are 0 and 1, is why i i have typed generic %d as example., in real situation i use 0 in my case ( just like your example in #19 ). it does not work ( notice it is just notebook oboard sound )
Click to expand...
I think the fact that we can see your output from sysctl dev.pcm will make it easier for people with more expertise to solve your problem.
The last thing I can personally think of is:
1. Apply my settings that I specified in the previous post
2. Then run the following command: mixer

What I sometimes see is that a seriously distorted sound can be produced in some situations when igain or ogain is set to 4 or another value different from 0.

Then I change this via eg mixer igain 0 or via mixer ogain 0 and then this distorted sound is immediately gone.

If that doesn't fix it I can't immediately figure out the reason for your problem, unless maybe because it could be a mic and output on the same jack, but I don't know, that's just a wild guess.
 
there is no igain or ogain for me:
Mixer vol is currently set to 90:90
Mixer pcm is currently set to 100:100
Mixer speaker is currently set to 100:100
Mixer mic is currently set to 50:50
Mixer rec is currently set to 1:1
Mixer monitor is currently set to 42:42
Recording source: mic
mixer igain 0
mixer: unknown device: igain
 
I actually have an old netbook with a newer version of FreeBSD that I use as a music player. The weird thing is that I also see ogain and igain there when I run the mixer command. So that's something I would investigate further, what the reason is.

This netbook only has two settings:
dev.pcm.0.bitperfect=1
hw.snd.maxautovchans=0

I don't see 'Mixer monitor' on my desktop, but I do see 'Mixer monitor' on the netbook, and that is set to 0. In my current setup, the sound is not played on the internal speakers but is sent to the audio output to which my headphones are connected. So set monitor to 0 by typing mixer monitor 0. That was the last thing I can think of, someone else can probably help you better. I'm not going to have time tonight to help you further.
 
Can you also post this:

Repeat for all /dev/mixerN

mixer -f /dev/mixer0
mixer -f /dev/mixer1
mixer -f /dev/mixer2
mixer -f /dev/mixer3
mixer -f /dev/mixer4
mixer -f /dev/mixer5
mixer -f /dev/mixer6
mixer -f /dev/mixer7
...

You can try to dump the mixer nodes that you don't use for playback.

You can try:
mixer -f /dev/mixer4 -s mix 0
mixer -f /dev/mixer5 -s mix 0
etc.

But only for the mixer nodes that you don't use..
It has solved other people's problem in the past.
 
i have only 5 of them:

mixer -f /dev/mixer0
Mixer vol is currently set to 86:86
Mixer pcm is currently set to 100:100

mixer -f /dev/mixer1
Mixer vol is currently set to 75:75
Mixer pcm is currently set to 75:75

mixer -f /dev/mixer2
Mixer vol is currently set to 100:100
Mixer pcm is currently set to 100:100

mixer -f /dev/mixer3

Mixer vol is currently set to 100:100
Mixer pcm is currently set to 100:100

mixer -f /dev/mixer4

Mixer vol is currently set to 86:86
Mixer pcm is currently set to 100:100
Mixer speaker is currently set to 100:100
Mixer mic is currently set to 50:50
Mixer rec is currently set to 1:1
Mixer monitor is currently set to 42:42
Recording source: mic
 
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