Optimizing Windows settings for Bifrost DAC?

[Madman242]

I've been wondering for some time about the optimal settings to use in Windows (7) with my Bifrost Uber USB. After much searching, I've yet to find a really definitive answer.
 
I have the Schiit USB driver installed, and am not sure what to use for the default format for the playback device. Should it be set to the max of 24/96, or should I match it to the source? I typically use Tidal streaming (16/44).
 
I'm also wondering if there is an optimal way to set the various volume controls in the chain. I typically set the player to max, Windows system volume to max, and then my Lyr amp to the max I will want to listen at. Then I use the computer volume to adjust it down for normal listening. Would it be better to keep the computer system volume at max as well, and then just use the amp to adjust?

 

[jcn3]

the big things you want to do in windows is make sure you're bypassing windows audio and going directly to the dac.
 
in control panel > sound -- make sure the bifrost is the default playback device. this will just make sure the bifrost is used even if you're doing something like streaming npr.
select the bifrost, select properties > advanced -- make sure the two check boxes for exclusive mode are selected.
in the tidal app, select settings > streaming -- make sure the quality is set to hi-fi and the sound output is set to the schiit device.
 
that should do it.
 
as far as volume goes, keep the computer volumes maxed and adjust the volume with the amp.

 

[Madman242]

@jcn3 Thank's for your reply. Luckily, I think I have most of those checked off. Do you have any suggestions as to what the default format should be set to? I just moved it back to 16/44 as that is what Tidal outputs. Does that make sense?
 
I'm curious as to the reason why computer system volume should be set to 100%? Is there a loss of quality if that is turned down?

 

[jcn3]

imo, i don't see any need to put that setting above 16/44.  note that's the default format is for shared mode -- since you're allowing the dac to operate in exclusive mode, this setting will be bypassed in most cases.  in addition, tidal is streaming at the highest bit rate of any service on the internet and it's only 16/44.
 
when you're using something like jriver to play ripped/downloaded files, jriver and the like allow you to bypass windows audio by using wasapi so you're bypassing that setting.
 
with the volume settings on computers, the change is done in the digital domain (by trimming bits).  this is not necessarily handled gracefully by computers, so people tend to prefer the volume adjustment being done in the amp by changing the amplitudes of the signals which doesn't trim information.  of course analog volume controls aren't perfect either, just the lesser of the two evils.

 

[Madman242]

@jcn3 That's a great explanation. I'm going to keep my computer volume turned up from now on!

 

[MindsMirror]

There's not reason not to set windows to 24 bit. You don't lose any precision when playing 16 bit audio, and you don't lose any precision if you decrease the volume (to a point) in software. If you set windows to 16 bit and you decrease the volume in software, you will lose some precision.

 

[jcn3]

  There's not reason not to set windows to 24 bit. You don't lose any precision when playing 16 bit audio, and you don't lose any precision if you decrease the volume (to a point) in software. If you set windows to 16 bit and you decrease the volume in software, you will lose some precision.

 
actually, i don't believe that's true.  if you're streaming something at 16/44 then upsample to 24 bits (padding with 0s) then use a digital volume control you'll have the same effect as using a digital volume control on 16/44.  you can't add bits that were never there.
 
of course, the whole thing is moot if you run the dac in exclusive mode since that setting is not used.
 
imo, you don't want windows to do anything it doesn't have to do.  the bifrost and the lyr are much more capable than the computer -- just feed them the bits as they come through and let them do their thing. 
 
of course, it can't hurt to try it and let your ears decide.

 

[MindsMirror]

   
actually, i don't believe that's true.  if you're streaming something at 16/44 then upsample to 24 bits then use a digital volume control you'll have the same effect as using a digital volume control on 16/44.  you can't add bits that were never there.
 
imo, you don't want windows to do anything it doesn't have to do.  the bifrost and the lyr are much more capable than the computer -- just feed them the bits as they come through and let them do their thing. 
 
of course, as you pointed out, it can't hurt to try it and let your ears decide.

Here is an example:
 
You have a 16 bit audio sample which is
1001101101101101
 
Windows and your audio software handle it in floating point precision (24 bit number and an 8 bit exponent which you can ignore in this example) until it is sent to the DAC, so you get this
100110110110110100000000
 
I've bolded the original 16 bits so you can easily see where they go.
 
You reduce the volume by 4x, which you can do in binary by shifting it twice, resulting in this
001001101101101101000000
 
Option a) Windows converts it to 16 bit to be sent to the DAC. It sends the 16 most significant bits which are
0010011011011011
 
Option b) Windows converts it to 24 bit to be sent to the DAC, sending the 24 most significant bits which are
001001101101101101000000
 
In option a), the two least significant bits of the original 16 bit sample were lost. In option b) they were not.

 

[jcn3]

i'm not an expert on how digital volumes work, but let me ask you this -- is this how it actually works?  by padding the zeros where you did, you changed the value of the bit stream.  if you pad it this way 000000001001101101101101 then you're not. it doesn't make sense to me that converting from 16 to 24 bits where you don't add any information that the effect would be different.

 

[Madman242]

I spent a little more time researching this when I got home from work tonight and found this interesting article: An audiophile's look at the audio stack in Windows.
 
It seems Windows upconverts all audio sources to 32 bits, so that the volume control has very little affect on sound quality.
 
As far as sample rate goes, it seems there is some benefit to matching your source material to prevent any distortion due to interpolation.

 

[MindsMirror]

You are right, padding an integer with zeros on the right would change the value. However in a sample of audio, you should think about it like this. The number that the 16 bit sample represents is not this
1001101101101101
it is this
0.1001101101101101
 
For simplicity I left that part out when I said you can ignore the floating point exponent in my example. A sample of audio actually represents a value between -1 and 1 (again, for simplicity I neglected to include a sign bit because it's not necessary so show my point, but if you want to be absolutely correct there should be a sign bit in there), so the 16 or 24 bit sample represents a fraction. When you pad with zeros to the right of the radix point, it does not change the value, you simply get this
0.100110110110110100000000
 

  it doesn't make sense to me that converting from 16 to 24 bits where you don't add any information that the effect would be different.

It is not in the conversion from 16 to 24 bits that the information was lost. It was in the final conversion from 32 bit float back to 16 bits. If you did the volume change in 16 bits, those two least significant bits would still be lost. Converting up to 24 bit or 32 bit float to do the volume change does not add information, it just allows you to not lose information.

 

[Blueshound24]

  the big things you want to do in windows is make sure you're bypassing windows audio and going directly to the dac.
 
in control panel > sound -- make sure the bifrost is the default playback device. this will just make sure the bifrost is used even if you're doing something like streaming npr.
select the bifrost, select properties > advanced -- make sure the two check boxes for exclusive mode are selected.
in the tidal app, select settings > streaming -- make sure the quality is set to hi-fi and the sound output is set to the schiit device.
 
that should do it.
 
as far as volume goes, keep the computer volumes maxed and adjust the volume with the amp.

I have tried both ways, set DAC as default playback device as well as JRiver WDM as default device in computer sound panel: (in control panel > sound -- make sure the bifrost is the default playback device).
 
Then, in Tidal > Settings > Streaming, it doesn't matter what I set, (JRMC 21 or Speakers PS Audio Perfectwave), when I stop and restart the Tidal app it reverts automatically to "System Default (Sound output is controlled in O.S. sound preferences".
 
Not sure why Tidal won't save the setting for JRMC or PS Audio DAC?
 
I am using WASAPI setting in JRiver and have WDM enabled as well.

 

[GumbyDammit223]

  the big things you want to do in windows is make sure you're bypassing windows audio and going directly to the dac.
 
in control panel > sound -- make sure the bifrost is the default playback device. this will just make sure the bifrost is used even if you're doing something like streaming npr.
select the bifrost, select properties > advanced -- make sure the two check boxes for exclusive mode are selected.
in the tidal app, select settings > streaming -- make sure the quality is set to hi-fi and the sound output is set to the schiit device.
 
that should do it.
 
as far as volume goes, keep the computer volumes maxed and adjust the volume with the amp.

I just learned of Tidal from this thread and got it installed last night.  When I set my Bifrost to exclusive mode in windoze, then go into Tidal and select exclusive mode there, playback is completely broken up and full of noise.  If I uncheck exclusive mode in Tidal, things sound normal.  Has anybody else experienced this?  BTW, I'm using Schiit's v1.0 USB drivers.  Their newer version won't install on my year-old Win7 machine.

 

[CFGamescape]

 
I just learned of Tidal from this thread and got it installed last night.  When I set my Bifrost to exclusive mode in windoze, then go into Tidal and select exclusive mode there, playback is completely broken up and full of noise.  If I uncheck exclusive mode in Tidal, things sound normal.  Has anybody else experienced this?  BTW, I'm using Schiit's v1.0 USB drivers.  Their newer version won't install on my year-old Win7 machine.

Try moving the playback cursor to a random spot in the track. That or restarting Tidal has fixed it for me.

 

[GumbyDammit223]

 
Try moving the playback cursor to a random spot in the track. That or restarting Tidal has fixed it for me.

Will give that a shot tonight, thanks.