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Volume control question

I wasn't sure if I should post my question here or under the Digital section but I figured this section gets a bit more traffic and its probably more relevant. I was reading a couple of articles talking about how digital volume controls could negatively affect sound quality, bit-stripping, etc. My bottom line takeaway was its not a good thing. This made me think about those of us who have streamers which provide a user mobile application which allows volume control among other things like music selection, etc. Is this considered a "digital" volume control? Is it better to set the volume to "fixed" as opposed to "variable" on the device and control the volume from the preamp? I haven't done a blindfold A/B test but I don't think I can tell a difference. Anyone else wondered about this or I'm just thinking too much...

Thanks. 

kalali
stfoth
435 posts
 
Kalali--I don't think you are thinking too much.  I wondered the same thing about using the volume controls on DACs.  There's a ton on it embedded in various Agon discussions.

--99% sure that the volume control of the bluesound through the Bluos app thingy is digital control.

For every DAC I've recently had, I prefer a separate preamp to the internal volume control--whether it's for whatever the preamp adds or whether it's for avoiding real or perceived nasties from the DAC's volume control.

I'm going to spend some time with a Bluesound going direct to an amp over the next couple of weeks...hope it works well.

What's working nicely for me is a Cary DAC200ts at full output through the passive of a Schiit Freya.  It's not a big difference and not night and day, but noticeable.  I haven't used it, yet, but the Cary has an iPhone app that lets you control the inputs, volume, etc. on the Cary through wifi.  That volume control remains digital.  The phone just works like the IR remote control, but through the wifi network to the antenna on the back of the unit rather than through it IR receiver thingy on the front.
stfoth
435 posts
 
This is a little old, but Bluesound being a little cagey about how it works--

https://helpdesk.bluesound.com/discussions/viewtopic.php?f=4&t=1867

kalali's avatar
kalali OP
1,645 posts
 

stfoth, greatly informative exchange in that link. Thanks for sharing. Just to avoid any potential bit-stripping, I always keep the volume control "slider" on the app above 50% and lower the volume from my preamp for lower volume listening. I suppose the best practice would be to set the volume on the Bluesound, or any streamer/DAC, to "fixed" which is basically a unity gain and control the volume in the analog domain using the preamp. It would be quite practical if the preamp has a remote control.


P.S. In hindsight, I should have posted this under Digital. Sorry about that.

stfoth
435 posts
 
Definitely a personal issue, but having a knob to turn is psycho-logically satisfying.
georgehifi's avatar
georgehifi
4,966 posts
 
I see this a lot, and there are two ways it can be fixed. "bit stripping" happens below 70% of full output on a digital domain volume control. 

1:This is why thoughtful/concerned source manufacturers like Wadia, Mark Levinson, Bricasti and a few others have "gain settings links" on some of their upper end models in the analogue output stage, to limit the maximum gain. So then the digital volume control upstream can be used at 70% or higher, for any system.

2:If you don't have these analogue gain settings, the next best is to use a passive volume control after the source, and set the volume on the passive so the digital volume on the source can be used above 70% this way you can still use the source remote volume control between 70 and 100%

Cheers George    
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