Does anyone make a digital in/out passive volume control?

[Elitzur–Vaidman]

What's your amplifier?

 

[RayDunzl]

My "digital volume controrl" practical experience:

By the time you attenuate the signal enough to cause audible degradation the remaining signal is too low to hear anything anyway.

That's around -70dB from a moderately loud start. I can hear something at that point, but would be unlikely to even identify a tune.

Call it 72dB, and that's about 12 bits lost - of 24 (or even 32) that is likely to be the bit depth in a competent volume control math, leaving 12 bits (or even 24) bits of near silence.

24 bit file before and after -60dB - the signal voltage is 1/1000th of the original:

 

[RickNRoll]

My MX Master 3 mouse has configurable controls on it for my PC. I have assigned the thumb wheel to be the windows volume control. Very handy.

You can't have a passive device that alters the volume of a digital signal. Just not possible.

 

[dasdoing]

My MX Master 3 mouse has configurable controls on it for my PC. I have assigned the thumb wheel to be the windows volume control

same

 

[Gruesome]

My MX Master 3 mouse has configurable controls on it for my PC. I have assigned the thumb wheel to be the windows volume control. Very handy.

You can't have a passive device that alters the volume of a digital signal. Just not possible.

If you are happy with 6dB steps, then chopping off whole bits from integers could be done passively, in a way. To divide by two, you need to route the signal over a parallel path, terminate the lowest bit trace/wire, route every trace/wire to the next lower bit, and put a pull-down resistor to create the new (zero) highest value bit. It's kind of passive, isn't it? You could do that with a 24 or 32 bit wide rotary switch, with 24 or 32 steps.
Each bit = factor 2 in output voltage = factor 4 in power (6dB in either case).
If the signal is signed integer, it get's a bit more complicated.

Do you guys think there is an audiophile market for this? It would be kind of in the opposite corner from the all-analog tubes-only market segment.
I'm thinking $1500, gold-plated contacts of course. ;-)

 

[SuicideSquid]

I'll throw another vote in behind something like this. There are lots of inexpensive USB knobs and multimedia controllers out there. If you just need something on your desk to give you additional control over Windows audio, that's going to be the simplest solution.

AFAIK you can't make a "passive" digital volume control - with an analog signal you can just attenuate the signal with a passive device, but you can't really do that to a digital signal. You have to unpack those 1s and 0s and turn them back into a waveform before you can do anything passive to it.

 

[Gruesome]

I'll throw another vote in behind something like this. There are lots of inexpensive USB knobs and multimedia controllers out there. If you just need something on your desk to give you additional control over Windows audio, that's going to be the simplest solution.

AFAIK you can't make a "passive" digital volume control - with an analog signal you can just attenuate the signal with a passive device, but you can't really do that to a digital signal. You have to unpack those 1s and 0s and turn them back into a waveform before you can do anything passive to it.

https://www.amazon.com/Griffin-Technology-PowerMate-Multimedia-Controller/dp/B00006BINO is what I have. Always reminded me a bit of the big red button of the internet. And it is a button that you can push, in addition to the rotary function!

And yes, you have to unpack the 0s and 1s, but I assume that happens somewhere inside the PC anyways; Mr. Gates wouldn't let those bits pass through his software without giving them a quick look-over, or what do you think? At that point you could make all the bits swerve right one or more lanes, so to speak. There's no waveform, just bits driving by on a parallel bus, and you're not really manipulating them, just giving them a little kick.

 

[Kal Rubinson]

I use this one: DROK

 

[Gruesome]

Apologies if somebody already posted this: There is a whole thread on attaching buttons/knobs to digital audio https://www.audiosciencereview.com/...r-raspberry-pi-help-needed-with-python.40320/ , with several solutions in there!