Schiit Modi and Magni comparison to Bifrost and Asgard
Dec 29, 2012 at 1:27 AM Post #17 of 312
The volume knob is a problem for me as well. Is there something I can do to change the potentiometer? 

As Defiant00 mentioned in his original post, you could use the computer volume control to do minor adjustments. I usually set my computer volume to around 50 then adjust the amp's volume to a comfortable level. Then you can do minor up/down adjustments from there with the computer's master volume (digital attentuation).
 
Dec 29, 2012 at 1:53 AM Post #18 of 312
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One of the most useful reviews I've seen on this site; A great model to follow. 

 
Thanks! That means a lot to me, especially considering how many excellent reviews there are on here.
 
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I think this is an important issue. It would be nice if the Magni's volume pot ramped up less aggressively. Irregardless, this combo is such a great value they're hard to resist!
You probably already know but just in case you don't, the Schiit return policy is 15 days.
I'd like to see someone do a blind test like this with Magni/Modi and O2/ODAC

 
Yeah, I fully agree; I think how the volume pot ramps up is probably its biggest weakness. Fortunately, the combination of low noise floor and 24 bit DAC means it becomes quite usable if you drop Windows' volume level a bit (just tried it a while ago with Windows set to 25%, which made it about as easy to adjust as the Asgard).
 
As far as returning anything, I'm actually going to be keeping it all at least until the Charlotte meet on the 20th, whatever I sell will go on sale there first. Besides, if it ends up being the Bifrost and Asgard then I'm over a year outside of the trial period already :)
 
Fully agree on the O2/ODAC, if anyone wants to send me them to compare I'd be happy to do so
smily_headphones1.gif

 
Dec 29, 2012 at 2:05 AM Post #19 of 312
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The volume knob is a problem for me as well. Is there something I can do to change the potentiometer? 

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As Defiant00 mentioned in his original post, you could use the computer volume control to do minor adjustments. I usually set my computer volume to around 90 then adjust the amp's volume to a comfortable level. Then you can to minor up/down adjustments from there with the computer's master volume (digital attentuation).

 
Alternately, you can set the computer volume fairly low so you have a large usable range. At around 25% on the computer I found that the Magni's volume control seems nicely accurate.
 
As stated before though, whether this degrades the audio quality is dependent on how you're getting the sound to the amp. For 16 bit music (aka, everything I listen to, CD rips and mp3s) into a 24 bit dac that leaves you with 8 extra bits to digitally attenuate the signal before you lose any data (in theory 25% should be 2 bits, so yeah, digital volume control away)
 
Dec 29, 2012 at 4:32 AM Post #21 of 312
Very nice write-up and that Blind A/B testing was quite convincing/shocking.  So tempted to get the M&M now...
 
And by the way, that's a very nice Go board in the pics. Just out of curiosity, is it for aesthetics or do you play as well?
 
Dec 29, 2012 at 6:08 AM Post #22 of 312
Great review man.

Thank you very much for sharing you're findings. I really enjoyd reading it.

I'm so looking forward to get my Magni.
 
Dec 29, 2012 at 6:53 AM Post #23 of 312
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Alternately, you can set the computer volume fairly low so you have a large usable range. At around 25% on the computer I found that the Magni's volume control seems nicely accurate.
 
As stated before though, whether this degrades the audio quality is dependent on how you're getting the sound to the amp. For 16 bit music (aka, everything I listen to, CD rips and mp3s) into a 24 bit dac that leaves you with 8 extra bits to digitally attenuate the signal before you lose any data (in theory 25% should be 2 bits, so yeah, digital volume control away)

 
 
im sure this belongs to sound science but if i want to line out, the digital volume on transport has to be maxed out to not lose data? is that what you are saying?
 
Dec 29, 2012 at 12:50 PM Post #26 of 312
For 16 bit music (aka, everything I listen to, CD rips and mp3s) into a 24 bit dac that leaves you with 8 extra bits to digitally attenuate the signal before you lose any data (in theory 25% should be 2 bits, so yeah, digital volume control away)

Is that what it is with the windows system volume control, 25% is 2 bits? I wasn't sure. I remember there being long discussions on the Squeezebox forums on the subject and what range would have impact on resolution.
 
Dec 29, 2012 at 1:38 PM Post #27 of 312
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Very nice write-up and that Blind A/B testing was quite convincing/shocking.  So tempted to get the M&M now...
 
And by the way, that's a very nice Go board in the pics. Just out of curiosity, is it for aesthetics or do you play as well?

 
I do play Go, just not recently unfortunately. My main playing partner now lives a couple hours away and I haven't gotten back into the online scene yet.
 
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im sure this belongs to sound science but if i want to line out, the digital volume on transport has to be maxed out to not lose data? is that what you are saying?

 
For 16 bit data into a 16 bit DAC, yes. For 16 bit data into a DAC set to a higher bit mode, no, you can digitally attenuate to a certain point without losing any data.
 
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Is that what it is with the windows system volume control, 25% is 2 bits? I wasn't sure. I remember there being long discussions on the Squeezebox forums on the subject and what range would have impact on resolution.

 
For integer values, yes, 25% (aka, dividing by 4) should result in using 2 of the extra bits. For more details see below.
 
Disclaimer, I'm a CS major but I'm not specifically familiar with the bit format used for USB audio. With that said, if you have 16 bit music and are sending it to a 16 bit DAC then any digital attenuation will actually lose data. With 16 bit data sent to a 24 bit DAC you have 8 extra bits (data in bold, extra bits red):
So for example:
1110111010101111                                Original 16 bit sample
111011101010111100000000                  24 bit representation (all samples just grow 8 zeroes at the end, same data, more bits)
 
Since each bit is a zero or one, to get half value you would effectively move each bit to the right once. So in the case of 25% you would do this twice. Here's how the same sample would look at 1/4 volume:
0011101110101011                              16 bit, all the numbers moved to the right twice and zeroes replace the leftmost bits
001110111010101111000000                 24 bit, in this case instead of throwing away the last two 1s they just moved into those extra 8 bits, so we don't lose those small details (and you've still got 6 extra bits for further volume adjustment if you need it)
 
This is all assuming USB audio sends the data as an integer, but if it's done as a float then it's a similar principal, just not exactly the same. If it is an integer then these 8 extra bits of padding means you can adjust your volume down to 1/256 and not lose data (256 = 8 bits = 2 ^ 8).
 
 
Anyways, ultimately the exact range you can adjust before losing sound quality is dependent on what your source is and how exactly it does the digital attenuation, but in general unless you go dropping the volume into the single percents you will likely not be causing any SQ loss. And just from listening, even at 5% I wasn't able to hear any difference with the Modi in 24 bit mode.
 
Dec 29, 2012 at 2:17 PM Post #28 of 312
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I do play Go, just not recently unfortunately. My main playing partner now lives a couple hours away and I haven't gotten back into the online scene yet.
 
 
For integer values, yes, 25% (aka, dividing by 4) should result in using 2 of the extra bits. For more details see below.
 
Disclaimer, I'm a CS major but I'm not specifically familiar with the bit format used for USB audio. With that said, if you have 16 bit music and are sending it to a 16 bit DAC then any digital attenuation will actually lose data. With 16 bit data sent to a 24 bit DAC you have 8 extra bits (data in bold, extra bits red):
So for example:
1110111010101111                                Original 16 bit sample
111011101010111100000000                  24 bit representation (all samples just grow 8 zeroes at the end, same data, more bits)
 
Since each bit is a zero or one, to get half value you would effectively move each bit to the right once. So in the case of 25% you would do this twice. Here's how the same sample would look at 1/4 volume:
0011101110101011                              16 bit, all the numbers moved to the right twice and zeroes replace the leftmost bits
001110111010101111000000                 24 bit, in this case instead of throwing away the last two 1s they just moved into those extra 8 bits, so we don't lose those small details (and you've still got 6 extra bits for further volume adjustment if you need it)
 
This is all assuming USB audio sends the data as an integer, but if it's done as a float then it's a similar principal, just not exactly the same. If it is an integer then these 8 extra bits of padding means you can adjust your volume down to 1/256 and not lose data (256 = 8 bits = 2 ^ 8).
 
 
Anyways, ultimately the exact range you can adjust before losing sound quality is dependent on what your source is and how exactly it does the digital attenuation, but in general unless you go dropping the volume into the single percents you will likely not be causing any SQ loss. And just from listening, even at 5% I wasn't able to hear any difference with the Modi in 24 bit mode.

 
 
 
wait but why is that if you are not lining out, you are free to mess with the digital volume without having to worry about losing data? as we all know, there has to be a dac and an amp to give sound for digital audio. so for not lining out, you are using a device's internal dac and amp. for lining out to another amp, you simply skip the internal amp and use an external amp, so how and why is that different from not lining out? or are you saying it doesnt matter if you lineout or not, its a matter of the dac, if its 16 bit audio going into 16 bit dac, you must max out volume to not lose any data, regardless of what amp you are using?
 
Dec 29, 2012 at 2:47 PM Post #29 of 312
That's pretty awesome. If I didn't enjoy the sound of Tubes so much (mmm dirty, dirty harmonics), I would consider getting it and replacing my Valhalla. And if I didn't like my optical out I would maybe even give up my BiFrost. I think Schiit has done a great job here. Those that want multiple interfaces in their DAC will do the BiFrost or the Balanced Gungnir, while the people who just need a great USB interface can do the Modi. Those that was a Tube sound or to drive really heavy orthodynamics can do the Valhalla, Lyr, or Balanced Mjolnir, while those who just need an efficient Amp can do the Magni. Personally, in my listening, I think the Asgard has been made obsolete by the Magni. The Magni is simply "good enough" at a vastly cheaper price point. The Modi however, I feel filled a very important, and missing niche for Schiit in providing a high quality, USB only DAC. To summarize, I feel the Magni replaces the Asgard, while the Modi provides a new high quality entry to complement the rest of the Schiit DAC lineup.
 
Dec 29, 2012 at 2:59 PM Post #30 of 312
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wait but why is that if you are not lining out, you are free to mess with the digital volume without having to worry about losing data? as we all know, there has to be a dac and an amp to give sound for digital audio. so for not lining out, you are using a device's internal dac and amp. for lining out to another amp, you simply skip the internal amp and use an external amp, so how and why is that different from not lining out? or are you saying it doesnt matter if you lineout or not, its a matter of the dac, if its 16 bit audio going into 16 bit dac, you must max out volume to not lose any data, regardless of what amp you are using?

 
Digital volume adjustment is just changing the bits before they even get to the DAC. If you're doing it in 24 bit mode then you're not throwing any data away, if you're doing it in 16 bit with 16 bit audio then you're throwing away actual audio data (whether you can hear it or not is another thing entirely).
 
Basically, your signal path is (Digital data, already volume adjusted by your computer) to (DAC, which converts it to analog and multiplies the signal by a fixed gain) to (amp, which adjusts the signal via a volume control and then amplifies it) to headphones.
 
Digitally adjusting volume means a quieter signal will be sent to and produced by your DAC. If your DAC or amp are at all noisy then this increases the chance that you'll hear the noise, since the signal itself is much quieter. This is typically why you'd want to line out.
 
Hope I explained it well enough, but if you have any more questions perhaps we should either take this to PM or maybe the Computer Audio or Sound Science sections.
 

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