[Acclaim]

Dearest head-fi members!
 
Having some trouble finding the best way to turn down the volume in my setup: Desktop -USB-> Schiit Bifrost -RCA-> Bottlehead Crack w/ Speedball --> HD650.
 
Ideally, and as I have read, I would like to control volume simply from the amp's volume pot with my computer volume set at 100%. There is no volume setting on the DAC.
 
With my volume set to 100%, I am in a narrow range of volume control between maximum preferred listening level and channel imbalance at low volumes. These correspond to a quarter turn and an eighth turn of the volume pot leaving me little room for control. Even at an eighth of a turn, it's louder than I would like for ambient listening.
 
I have looked into adding resistors to the Crack and have them sitting here... but am trying to avoid the disassembly/reassembly if possible.
 
Thoughts?

 

[Head Injury]

tl;dr Turn your computer volume down, you're fine.
 
Here's how digital volume control (like the one your computer uses) works:
 
Digital resolution is limited by the bit depth. As the volume increases or decreases, the digital signal has to round it to fit one of the values the bit depth can resolve, and this rounding creates noise (called "quantization noise"). The more bits, the smaller the volume steps and the less rounding, so less noise. It turns out that each bit lowers the noise floor by -6 dB. 16-bit signals have a quantization noise floor of -96 dB, and 24-bit signals have -144 dB.
 
The problem is, since this noise floor is determined by the bit depth, it will not go down when you turn the digital volume down, like the noise introduced by an amp will. So if you have a 16-bit file and turn the volume down by -10 dB (1/2 the volume), the peak signal that was 96 dB above the digital noise floor is now only 86 dB above it. The signal-to-noise ratio was reduced by -10 dB as well. This is why people recommend using the analog volume control.
 
This is made moot by the fact you're probably not listening much louder than 80 dB, and your room's ambient volume is likely around 30 to 50 dB, and you're probably not even getting 96 dB of signal-to-noise ratio from your gear anyway.
 
Plus, if you're using your DAC in 24-bit mode, you have 8 extra bits to use for volume control. Meaning you could lower the volume by 48 dB (that's about 1/28 the volume) in the digital realm without reaching the noise floor of the 16-bit file you're playing, or the noise floor of your equipment. Digital volume control will only matter if you're raising the noise floor above the rest of your noise, and you're not realistically going to do that.
 
So turn down your computer volume, you're fine.

 

[germanium]

  tl;dr Turn your computer volume down, you're fine.
 
Here's how digital volume control (like the one your computer uses) works:
 
Digital resolution is limited by the bit depth. As the volume increases or decreases, the digital signal has to round it to fit one of the values the bit depth can resolve, and this rounding creates noise (called "quantization noise"). The more bits, the smaller the volume steps and the less rounding, so less noise. It turns out that each bit lowers the noise floor by -6 dB. 16-bit signals have a quantization noise floor of -96 dB, and 24-bit signals have -144 dB.
 
The problem is, since this noise floor is determined by the bit depth, it will not go down when you turn the digital volume down, like the noise introduced by an amp will. So if you have a 16-bit file and turn the volume down by -10 dB (1/2 the volume), the peak signal that was 96 dB above the digital noise floor is now only 86 dB above it. The signal-to-noise ratio was reduced by -10 dB as well. This is why people recommend using the analog volume control.
 
This is made moot by the fact you're probably not listening much louder than 80 dB, and your room's ambient volume is likely around 30 to 50 dB, and you're probably not even getting 96 dB of signal-to-noise ratio from your gear anyway.
 
Plus, if you're using your DAC in 24-bit mode, you have 8 extra bits to use for volume control. Meaning you could lower the volume by 48 dB (that's about 1/28 the volume) in the digital realm without reaching the noise floor of the 16-bit file you're playing, or the noise floor of your equipment. Digital volume control will only matter if you're raising the noise floor above the rest of your noise, and you're not realistically going to do that.
 
So turn down your computer volume, you're fine.

I Agree.
 
Actually digital volume control handled in 24 bit mode is far superior to any analog volume control & yes I have tried them all. You don't get the volume imbalance nor the increased output impedance (critical if not using any buffer amp after) & or reduces the necessary stages of amplification Nor do you get as severely limited in you volume selections as to do with many of your volume pots that used fixed resistors.
 
Also with an unbuffered volume control you get shifting output impedance with different volume settings & usually the output impedance is highest near the desired listening volume. Cabling for low signal loss in such conditions can be a nightmare. I had to make my own ultra low capacitance cables in order to get the sound I wanted out of them & I also had to keep them shorter than 1 meter. With the digital volume control with my ZXR soundcard out putting 24 bit audio I don't have to worry about that as the output impedance is both low & constant across all volume levels. I could use longer cable runs without noticeable loss.

 

[nottheface]

  tl;dr Turn your computer volume down, you're fine.
 
Here's how digital volume control (like the one your computer uses) works:
 
Digital resolution is limited by the bit depth. As the volume increases or decreases, the digital signal has to round it to fit one of the values the bit depth can resolve, and this rounding creates noise (called "quantization noise"). The more bits, the smaller the volume steps and the less rounding, so less noise. It turns out that each bit lowers the noise floor by -6 dB. 16-bit signals have a quantization noise floor of -96 dB, and 24-bit signals have -144 dB.
 
The problem is, since this noise floor is determined by the bit depth, it will not go down when you turn the digital volume down, like the noise introduced by an amp will. So if you have a 16-bit file and turn the volume down by -10 dB (1/2 the volume), the peak signal that was 96 dB above the digital noise floor is now only 86 dB above it. The signal-to-noise ratio was reduced by -10 dB as well. This is why people recommend using the analog volume control.
 
This is made moot by the fact you're probably not listening much louder than 80 dB, and your room's ambient volume is likely around 30 to 50 dB, and you're probably not even getting 96 dB of signal-to-noise ratio from your gear anyway.
 
Plus, if you're using your DAC in 24-bit mode, you have 8 extra bits to use for volume control. Meaning you could lower the volume by 48 dB (that's about 1/28 the volume) in the digital realm without reaching the noise floor of the 16-bit file you're playing, or the noise floor of your equipment. Digital volume control will only matter if you're raising the noise floor above the rest of your noise, and you're not realistically going to do that.
 
So turn down your computer volume, you're fine.

This was great!  I just got my first amp and have been struggling with the volume.  Pretty much anything higher than "1" was too loud.  Knowing I can dial down the computer volume without adversely affecting the sound quality is a huge relief.  I now have it sitting at 3, and it sounds noticeably better.