ALLO USBridge ~ DAC Volume control Vs Software Volume control Vs Preamp Volume control

[reachkalyan.kr]

Hi,

Confused - which one is best in this chain to control the Volume for an Power Amplifier.

Any Fm's here carried out some R&D and settled on something ?Chain of components mentioned below.

Source - USBridge- Volumio/ Moode Audio sw Volume control.
DAC - similar to D50s / E30 model which has remote for volume control
Dedicated Power amp - with Balanced / Unbalanced input.


If dedicated pre amp is preferred which one is preferred.
Passive/ Active pre / Atteneuator /with remote volume control.

 

[shyamv]

In your chain, letting DAC do volume control (which is essentially a digital volume control) would be better even though D30/E30 preamp functionality isn't that well-reviewed but it would be better than Volumio/Moode software volume control algorithms.

But you use something like foobar as your audio player, then software volume control would be significantly better than the DACs you mention above.

It is 'generally' believed that transformer-based volume control is better than resistor-based control which is in-turn better than digital volume control. So you can look for a preamp with this functionality. But there is another smaller group believes that that there is no point adding to the digital to analog chain and hence there is no need for analog preamp and volume can be done in digital or software domain. This is the extent of my knowledge on this subject .

If you wish to get understand more, you can take a look at 'objective' groups such as AudioScienceReview for more 'expert' reports from measurement fanatics and you can find a few hundred posts on this very topic.

 

[Kannan]

Preamps are the heart of the audio chain like the baton passed between athletes in a relay race. Their duty is to pass the source information without colouration to the power stage that drives the speakers.
It is easier said than done due to issues like impedance matching, cross talk, channel imbalance and signal distortion with attenuation.

1. As most modern digital sources output a healthy 2 volts or above, the digital attenuation implemented in mpds associated with Volumio and MoOde are absolutely bit perfect and would be a good way to go. Overall bit perfect attenuation are usually immune to bandwidth restriction, channel imbalance and crosstalk.
That said some find the digital attenuation a bit dry.

2. Defeating the mpd volume control is beneficial if the preamp implementation is good on the DAC if ofcourse it has one built in.

4. Coming to analogue pres, if you have multiple sources, often that is the only option left.
Here too depending on the overall source volume one can take the active or passive route.

Well implemented passive preamps are considered the most uncoloured, but will be expensive to achieve. Here too options range from transformer based to stepped attenuation to LDR types or zero gain buffers

Active preams are the most common and are the standard ones with integrated amps and will normally also have tone controls.

It is difficult to hit on any one and will depend on the rest of the components.