Hello there,

My name is Paul, 51 years young and i live in the Netherlands.
Not a Volumio user yet…but one with questions…

I’m a hifinutter and not a person who knows computers.
At this moment my hifiset plays music only digital via streaming from a nas.
The contents of the nas are controlled via Albumplayer with ASIO for bitperfect playback.
This “bitperfect” is very important to me.

I’m almost ready to downsize and simplifying my streaming setup with a RPI or ALLO Sparky but definitely with the ALLO Kali reclocker.
My 1794 DDDAC NOS is fed now with music via usb (wave-io) and that is put into I2S signals which feeds my dac.
With de RPI, or Sparky, complemented with the Kali the usb is out of the equation because this setup gives me I2S directly.
Simpler, better sound quality.

My question is this;

If i’m not mistaken you claim to be bitperfect but i read that you implement digital volume control.
This means that the datastream is tempered with if i’m correct and please correct me if i’m wrong.

Is there a possibility to switch off this digital volume control and then can you guarantee me then that the signal path is bitperfect ?

Thanks in advance!

With regards, Paul

Hi Paul,
first, let’s start by clearing this:

  • It’s not true that enabling volume control ALWAYS tampers with bit perfect.
    There are 2 ways to get Volume control:
  • Software mixer: the audio streaming is manipulated to get the desired volume change. This makes the stream not bitperfect, and degrades sound quality
  • Hardware Mixer: its not supported by every DAC, but if the DAC supports this, it will trigger its array of internal resistors to change the volume. In this mode, you can change the volume while keeping bit perfect and without any audio quality degradation.

Volumio can detect if your DAC supports Hardware mixer, and enable it automatically. If your DAC does not support it, Volumio will allow you to enable software mixer.

Speaking of your desired choice: you will most likely not have hardware volume into your DAC (I don’t know if its compatible with the Kali). But if you want bit perfect sound, you can just leave volume control at “None”, which disables it.

Wow, Michelangelo, you are seriously fast which is great, so thanks for your speedy reply.

You know how ASIO works?
It sidetracks/skips all Windows intervention from the audio datastream, hence it creates a pathway to get the signal as fast as possible in the shortest way out of the computer.

I don’t want or like any volume control, or equalization at this point to be specific, i use volume control after it has left the dac with the pre-amplifier.
The dac itself has a I2S input and gives an analog output to my pre-amp.

The ALLO KALI reclocker is a shield which delivers a thoroughly cleaned I2S datastream and is compatible with this dac, for sure.

So i’m lookin’ for a clean, undisturbed audiostream.
I do not like to tick boxes in the setup but would like to discard the volume control completely, on software level?
ASIO does that in Windows
Is that possible?

Cheers Paul

Dear Paul,
the core feature of Volumio is that it sends the audio stream as untouched as possible to the DAC. We’ve done a lot of optimizations at Operating system level to achieve this. Like running the least possible number of system processes, sending audio directly to the card without any resampling, nor convolutions.
I might say that we’ve done things differently than Asio, but with the same purpose. And I hope with a better result.

Volumio will automatically configure itself for the best sonic result possible.
However I’m not sure the Kali will be compatible with your DAC: your DAC needs to be in slave mode (aka take the clock from the Kali). It will not work if in Master mode.

Hope it’s everything clear, let me know if you’ve more questions

Hi there michelangelo,

Thanks for your clear explanation of how VOLUMIO handles the audio data stream.
Furthermore, I can assure you that this dac is a slave thus in slave mode.
The Kali therefore is a welcome attribute in cleaning the I2S signal from the “dirty” clock signal from the pi and replacing this with a fresh better clock signal.
There is more audio upgrade news, ALLO, there on the brink of releasing a hat that separates the pi or Sparky galvanic (don’t know if I explain and spell this correctly) from the Kali.
This means that the signal path will be exchanged with the Kali like a transformer, with no physical contact between the two. Great news for audionutters like myself.