Digital volume control

[pmcuk]

There's been a fair amount of discussion about volume controls recently, and it would be helpful to hear from those on the forum who can talk with some experience about digital volume controls. Plus anyone who has any views and ideas to share. I freely admit that digital electronics is outside my knowledge base and I'd welcome an educational thread on the subject! I did find this thread interesting as a starter....

https://audiophilestyle.com/forums/topic/17052-32-bit-sound/

One central question to answer is how close to "lossless" or "least lossy" you can get in software and how this relates to 24 and 32 bit float. I've read that iTunes can utilise a 32 bit float, but not sure what this means in practice. In my case all my sources are on my Mac Pro, though YMMV. 

 

[Rayymondo]

Can't comment on the more technical part of your question but from personal experience I didn't enjoy the digital volume in my Linn ds streamers ( Sneaky and Renew)

I much preferred the sound when I installed either a separate pre amp or an integrated amp, I found it warmer, fuller, more "musical" and ultimately more enjoyable.

However I am led to believe that the more recent incarnations of the digital volume ( on Linn and I daresay other manufacturers) has come on leaps and bounds in the last few years. I think it will depend massively on the components in question and when they were made. Older digital gear seems to suffer with some loss with digital volume but maybe not the newer stuff, providing you are buying quality of course.

 

[MartinC]

My first good experience with a source with a digital volume control connected directly to a power amp was what would now be considered a pretty old Wadia unit. Implementation definitely matters but I don't think it's exclusively a new thing to be got right.

I use digital volume control in my system but my switch to doing so was driven by it opening up better subwoofer integration to me. 

 

[Phobic]

I've only had a similar experience to @Rayymondo a Linn streamer directly connected to a power amp, it was very harsh, too harsh in fact, I hated it. a pre-amp really sorted it out.

I'm a bit confused by the question on 32 bit floating point - I thought that was more a mastering question?! can some explain please

 

[Jazid]

I've been using both for ten years now. To my ears digital volume control is neutral with no audible degradation. In my chain I have 64 bit, 32 bit and whatever the ESS9018 DAC has for but depth. I use the 32 bit control because they all sound the same to me and it is most convenient. I use analogue to level match analogue sources and for various bits and bobs. It's OK, but some seem to change the tone a fraction as the levels change.

Honestly don't sweat it, the difference is closer to cable changes than valve rolling...

 

[Gray]

When you initially setup Volumio (which I use) they point out that, if you choose the software volume control option, you're no longer bit-perfect.

If your DAC is compatible with hardware volume control, then you can choose that option (for convenience with no potential audio compromise).

My current (Khadas Toneboard) DAC allows hardware control, but I just do what I've always done - choose Volumio's 'none' option (for default 100% RPi output) -  and do all volume control with my amp.

 

[Nopiano]

I’ve also been interested in this, especially since buying a streamer-preamp with the aim of moving one day to active speakers, thus eliminating my integrated amp.  

I struggled with the Audiophilestyle thread, but I do just about understand this White Paper from Linn, in which I think they’ve tried hard to use plain English (or, perhaps, Scottish!).  At least the graphics bring it to life for me in a way numbers alone cannot. 

https://small.linncdn.com/white-papers/evolution-of-the-pre-amp.pdf

 

[pmcuk]

Thanks for the Linn link. Useful reading. They are talking about implementing a digital volume control between source and DAC, which is what their preamps do. This is one way of doing it and well worth knowing about.

I'm more interested in a digital volume control in the source itself. Right now I'm doing this in whatever I'm using - a website, TV channel or iTunes. And the means of changing the volume is a mouse, rather than a handset or a rotary pot. This is undeniably very convenient, so optimising the software and the hardware in the computer would be very attractive to me as a preference. 

 

[Rayymondo]

They are talking about implementing a digital volume control between source and DAC, which is what their preamps do

I think their preamps might be analogue, but the stand alone streamers have built in digital volume, that's what I didn't get on with. I also have a Wyred 4 Sound headphone amp / pre amp / dac which I believe uses digital volume . I only like that when I am using the headphone section which is class A analogue. Maybe it's just not for me, at least the ones I've heard so far at least. I don't doubt there are good implementations that I might enjoy... most of our experience is limited!

 

[H20gna]

I have an active pre amp where the implementation of the  PGA 2310 chip to control volume is in the digital domain rather than any analogue device.

I realise this perhaps is not exactly what your discussion is about, rather bringing to light the availability and very high SQ of such a device.

Gary.