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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. 

128x128kalali
10 responses Add your response
hgeifman
2,187 posts
 
I started using a DAC with volume controls going direct to a power amplifier and did not like the sound quality. I was running between -20 to -40db and noticed the bit reduction was impacting (greatly) the sound quality.

However, every DAC and power amplifier combination may offer different results so I suggest you test these combinations yourself.

I switched DAC's and the noticed a slightly improved sound quality but not where it needs to be.  As a result, I am researching a preamp/DAC.  

It seems everyone has a different opinion based on their equipment and environment.  Based on my experience, I have decided a preamp is required between the DAC and power amplifier for maximum sound quality.

I suggrst you you run your DAC direct into your amplifier and then insert a preamp in and see how it sounds. Please keep us posted.  Thanks. 


kalali's avatar
kalali OP
1,977 posts
 
Maybe my question was poorly worded. To be more specific or just use Bluesound Node 2 streamer as an example, I'm asking about the remote volume control on the mobile application.
hgeifman
2,187 posts
 
Sorry, I did not understand your original question. I do not know the answer so I am going to "guess" and let someone else answer.

As I understand it, the mobile app is controlling the volume control on either the DAC or the preamp probably via Bluetooth or something similar.  My assumption is the net result depends on the volume control on the DAC or the preamp.

The volume control on the mobile app is sending a signal to either device and the device (DAC, preamp or Bluetooth Node 2 streamer) controls the volume.

I hope someone else can provide a better answer to this question.
kalali's avatar
kalali OP
1,977 posts
 
Thanks. It appears that the "volume control " on the mobile app is changing the volume in the streamer through the WiFi connection. Definitely not the preamp since the volume control on the preamp is unchanged. I guess the real question is whether or not changing the volume on any device that can be controlled via WiFi, or Bluetooth for that matter, using a mobile device, is done in digital domain. This is of course completely different from controlling the volume via a remote control, e.g., infrared, etc., where the volume control is motorized and actually moves up or down. 
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kalali's avatar
kalali OP
1,977 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.

Post removed 
georgehifi's avatar
georgehifi
10,312 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    
kalali's avatar
kalali OP
1,977 posts
 

Thanks George. I couldn't quite follow the details of what you described but I get the 70% threshold. I was sort of using 50% as a bogie but will now change that to 70%. Between the (analog) volume control on the preamp and the volume control on the mobile app its pretty easy to modulate the desired listening levels.

Ironically, the entire premise of this discussion is based on the laziness to get off our butts and just change the volume. First world challenges...

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