Source vs Dac vs Amp Volume

[Agile_Interest]

First of all I just want to say I am very new to audio and would appreciate it if you could explain everything in plain english that even a 5 year old could understand .

I have been doing some reading on what the best settings are when it comes to volume on my computer connected to my SMSL D1 DAC via toslink cable then xlr out to my Cayin IHA-6 for highest fidelity. I have always set the volume on my computer and Tidal to 100%. On my D1 I have it set to 25 (max is 38) since, as I understand it, the D1 is changing voltages when you do this and I would like to keep the DAC cool. On my Cayin I keep it at low gain, low quiescent current, if I can get the headphones loud enough (using 4pin-xlr out) without going past 12 o'clock, if not, I put it at high gain, low current.

So, can someone please explain what settings I should use on my computer/player, on my DAC, and what I should use on my amp for best audio quality/lowest noise possible? Also, please can someone explain what the F*** quiescent current is and whether I should be using low or high quiescent current, and whether it matters how much I turn the volume knob on my amp? And is 24 bit/48k usually the best when listening to say Tidal for instance? Thank you for any help, I know it's a lot of questions.

Side note: What filter is best on the D1? So many filters, and I don't really know what they do, but I do hear a very small difference.

 

[twsecrest]

The device (amplifier), at the end of the audio train, should be the device used to control volume.
All other devices (PC ,DAC, etc), in the audio chain, should have the volume settings as high as possible (75%-100%), to send the strongest signal to the device (amplifier) at the end of the chain. If some device in the audio chain, with the volume controls set to 100%, introduces noise into the audio signal, you can turn down that device's volume control, until the noise is removed.
CD-audio is 16-bit/44.1K, so 24-bit/48K setting should cover you for any (99.99%) music audio, I doubt most stream audio music would be higher then 16-bit/44.1K. Blu-ray movies disks or special HD-audio might give you a reason for using a setting above 24-bit/48K

 

[daftcombo]

I agree with twsecrest but:
if your DAC has saturation at max level (it is the case for Topping DX3 Pro for instance, see here the IMD graph: https://www.audiosciencereview.com/...of-topping-dx3pro-dac-and-headphone-amp.4967/ ),
IMO you'd better set the volume of the music player (Foobar2000, JRIver, or any player working at 64bit) to less (like -5dB to stick to the Topping example).
Not that you will hear a difference, but theorically, it would be safer.

 

[differenceclouds]

It really depends on the setup. Especially if you're working with older gear, you often need to balance everything to reduce noise or distortion. Newer gear, especially the stuff recommended here doesn't have these issues.

If your (pre)amp has channel imbalance at low levels for example, or you simply want a more useful range of usability from your main volume knob, attenuating at a previous stage is better. Specifically the stage right before, with all stages before that being at 0dB unless there is some other issue. There used to be more issues with digital volume controls impacting sound quality but these are mostly gone.

I had an audio interface that clipped in the last 10% of the range of the volume control, so in that case I attenuated in the mixer software for the interface. I also had a preamp that had a constant level of hiss irrespective of its volume, so I attenuated *after* in that case to remove the hiss. With my current setup, I don't have any of these issues, so.... I don't worry too much about it (can't you tell?) and set the DAC at a level that gives me good range from my main volume knob.

I guess it's good to *know* there are no noise issues in your setup using simple methodology, but uhhh... you used to be able to *hear* the noise and adjust accordingly. With modern setups you're adjusting for noise you can't even hear lol.