Hello,
I am using Volumio/Raspi as Streamer for DIGI out (Hifiberry) for my active LS. Is there any possibility to use a DAC for (almost) lossless Volume Control in Volumio? Fiddling around with the plastic Hypex remote and the volumio app is not a decent solution…
Best
Andreas
Please elaborate in more details what you want to do. There is to much info in a few lines.
Do you want the active speakers full open and control volume via Volumio, if that’s the question:
Hi, a HAT…
Maybe thsi link might help you:
Well, I guess the problem is the DIGI out. DAC Volume Control is normal. But for analog outputs. I tried a Hifiberry DAC with Digi In/Out ports. Complete fail. Anyone using Dac, Vol Control and DIGI out?
Best
Andreas
With Digi out is not possible. You need to use software volume, but this comes with sound degradation.
Your best bet is a USB DAC
Sound degredation is no option. I will stick to the crappy Hypex remote (or buy a Bluesound node)…Thank you for the support.
I didn’t believe the difference would be noticeabe (or that my ears would notice) until I replaced my HifiBerry hat with a very affordable Topping D10S, but the improvement was obvious and significant.
You will be back at square one, S/PDIF does not have hardware volume…
But Bluesound Node digital RCA can use Hardware Volume as far as I know…
Where did you read that? Link?
My brother owns one and is using it with RCA digital for connecting hypex active LS that way
Okay. I still don’t.fully understand. The USB Dac would be working as the port has a mixer that can be controlled by Volumio? If that is the case why do I need an additional DAC as I convert in the Hypex Module anyway? Would be an USB Coax/SPDif adapter suitable?
Thank you
Andreas
the S/PDIF is a very old standard protocol, it does not allow to send values and/or commands for volume control to the receiver side.
If the Bluesound Node has volume control capabilities on the S/PDIF interface, it means the output stream is sent already attenuated to the receiver. Thus, it is a SW volume control, not an hardware one. You can obtain the very same result enabling SW volume control on Volumio.
I thought that the DAC is changing the volume information in the digital output. Like an EQ on all frequencies. But I obviously have no clue. 
So a software volume control…
Also think, that in order to control the volume on S/PDIF, the digital (RAW) signal needs to be converted to PCM first.
I’d like to elaborate a bit more on what I claimed before, with a high-level explanation on how HW volume control works
When using a I2S DAC with Hardware volume control
** the audio stream is sent “as-it-is” to the DAC via I2S interface, so bit-perfect / full-scale at 100%
** the volume value is sent by the linux driver via I2C interface to the DAC, and the DAC makes use of this value to adjust the level of the analog output ath the very end of the signal chain
When using a USB DAC with Hardware volume control
** USB is a universal interface, it can be used for different things, also simultaneously
** the audio stream is sent “as-it-is” to the DAC via UAC protocol, so bit-perfect / full-scale at 100%
** the volume value is sent by the linux driver to the DAC via HID or similar protocols, and the DAC makes use of this value to adjust the level of the analog output at the very end of the signal chain
When using a S/PDIF interface
** S/PDIF is a very old standard protocol, with well defined structure for the data.
** The S/PDIF protocol does not have the volume/attenuation information in the data structure
** It’s not possible to send the volume value to the receiver DAC, to be used for HW volume control as done for I2S and USB.
** if it’s possibile to have volume control on the Bluesound Node connected via S/PDIF, it means the audio stream is sent attenuated (so it’s manipulated, not bit-perfect) to the DAC, because it’s not possible to do otherwise.
Hello Dario,
thank you for the summary. What happens when I use a digital RCA or SPDIF out on the USB DAC? Can that be controlled by the Volumio hardware mixer?
Best
Andreas