[mrjayviper]

As above.

The 2 DACs I have already has digital volume control which I believe are provided by the AKM/ESS chip.



Thanks

 

[PurpleAngel]

Best to use the device at the end of the audio chain (head amp) to control volume.
And max out, or near max out, the volume control on the other device, before the amp.

 

[mrjayviper]

Best to use the device at the end of the audio chain (head amp) to control volume.
And max out, or near max out, the volume control on the other device, before the amp.

any explanation for this setup? Thank you.

EDIT: what's the difference of doing the volume attenuation at the DAC vs the input of the headamp?

 

[ClieOS]

Typical digital volume control on (especially older) the DAC chip does so by reducing the bitdepth of the music. Every bit taken give -6dB of attenuation. A poorly implemented digital volume control ends up taking too many bitdepth from the music and might turns your 16bits music to 13bits (or less) which in effect reducing it's SQ. However, good DAC chip might have internal resampler to increase your originally 16bits music to 64 bits first before applying digital volume control and those will not likely to hurt the final SQ. However, out of old habit many audiophiles usually just avoid digital volume all together and use an analog volume control at the last possible analog stage as it usually will give you the best possible SNR without any worry of whether there is any deterioration of SQ due to poor digital volume implementation.

 

[mrjayviper]

Typical digital volume control on (especially older) the DAC chip does so by reducing the bitdepth of the music. Every bit taken give -6dB of attenuation. A poorly implemented digital volume control ends up taking too many bitdepth from the music and might turns your 16bits music to 13bits (or less) which in effect reducing it's SQ. However, good DAC chip might have internal resampler to increase your originally 16bits music to 64 bits first before applying digital volume control and those will not likely to hurt the final SQ. However, out of old habit many audiophiles usually just avoid digital volume all together and use an analog volume control at the last possible analog stage as it usually will give you the best possible SNR without any worry of whether there is any deterioration of SQ due to poor digital volume implementation.

Do you have a link with this info?

I looked at the datasheet of the DAC chips (AK4499 and ESS9038pro) used on my devices and can't find such info.

Thanks

 

[PurpleAngel]

any explanation for this setup? Thank you.

EDIT: what's the difference of doing the volume attenuation at the DAC vs the input of the headamp?

The thought process is you want to send a strong signal (audio signal) to the last device (amplifier) in the audio chain.
But controlling volume from the DAC might just be a more personal choice.
I will control volume using my tube headphone amplifier, as a pre-amp, to control volume to my desktop monitors (my choice).

 

[ClieOS]

Do you have a link with this info?

I looked at the datasheet of the DAC chips (AK4499 and ESS9038pro) used on my devices and can't find such info.

Thanks

Here is something ESS put out over a decade: ago - https://diyaudio.pl/downloads/digital-vs-analog-volume-control_by_ess.pdf

I recalled AKM posted something similar a long time ago as well, can't remember where it is anymore.

 

[mrjayviper]

The thought process is you want to send a strong signal (audio signal) to the last device (amplifier) in the audio chain.
But controlling volume from the DAC might just be a more personal choice.
I will control volume using my tube headphone amplifier, as a pre-amp, to control volume to my desktop monitors (my choice).

In a speaker chain (like a floor standing home setup), the volume control is in the preamp and not in the amp. So you're already controlling the volume immediately at the preamp input (much like controlling it on the DAC)

Same situation in a headphone amp. The volume control is in the input.

 

[wirewiggler]

In roon playback. I believe volume control is implemented through DSP while it is not reducing bit count it still is being exposed to one more digital process, it depends on how much faith you put into bit perfect delivery in the end. I run mine at 100% out for normal listening levels ( adjusting the volume control on the headphone amp) and reduce or muting it digitally when needed.

 

[A Jedi]

If you're a purist, control the volume at the amp. No digital compression and a strong signal all the way to amplification (less relative noise will be picked up on the way). If you're not a purist, do what makes you happy.

 

[tomb]

In a speaker chain (like a floor standing home setup), the volume control is in the preamp and not in the amp. So you're already controlling the volume immediately at the preamp input (much like controlling it on the DAC)

Same situation in a headphone amp. The volume control is in the input.

The problem is in the nature of a source vs. other components in an audio string. With a truly weak signal source, such as a microphone, phono input, or tuner antenna connection, the last thing you want to do is attenuate an already very weak signal. That's because you're often at the physical limits of reasonable gain ratios, and noise, hiss, and hum will be the result. The alternative is to attenuate the signal on the output (for a source). That function is already provided in most audio strings by the pre-amp or headphone amplifier inputs.

In the case of a DAC, of course, the signal on the input side is undergoing a conversion from a digital form to an analog form. You don't need to read the datasheets to figure out whether a DAC (or software music player) is affecting the quality of the signal stream if it implements volume control on the input side: it can't be done any other way. Applying an analog attenuation to a digital signal stream is impossible. Thus, the digital stream is manipulated if the volume control is not on the output. You can argue whether that affects the quality, but the very idea is in conflict with trying to preserve the digital stream as "untouched," which is the goal for which every audiophile strives.

If an analog attenuation is placed at the output of a signal source ahead of a pre-amp, or if it's placed in the preamp - it makes no difference. The function is the same in either component, so long as it's not included in both. If included in both, then you get the ubiquitous question that keeps getting asked on Head-Fi - "How do I best control volume, with my DAC or my amplifier?" You also get twice the noise, because you have two attenuation circuits that the analog music signal has to traverse. (If there weren't noise consequences to using analog volume controls, there would be no market for expensive stepped attenuators.) There are RC circuit implications as well (potential bass loss), depending on whether output or input capacitors are present.

P.S. A Jedi said it much more simply.

 

[wirewiggler]

Well I could spend all night thinking about it, in the end I just sat down and enjoyed it.