Hi all!
I’ve always wanted to try Volumio. I found time for this, installed the version ported to the Orange Pi PC (H3, 1GB of RAM), connected a 7-inch touch screen, and installed several plugins (via SSH). Yesterday I updated to version 3.611.
I connect the resulting streamer via a USB interface (tried to use all available USB connectors) to the Rotel RA-1572 integrated amplifier. The amplifier was specially configured for USB audio 2.0 mode. The Volumio settings are as follows:
Output Device - USB Audio 2.0 DSD Playback Mode - DSD Direct DSD Auto Volume Level - Off Volume Normalization - Off Audio Buffer Size - 4 Mb Persistent Queue - OffPlayback Mode - Single
Mixer Type - Software or Hardware or None Default Startup Volume - Disabled
Audio Resampling - Off
After turning on the amplifier (Volumio detects a USB audio 2.0 device), a strong digital noise (white noise with other various components) is heard from the acoustics, which continues until I select a new track/radio or something else.
I can’t start the track that was there earlier - Volumio doesn’t respond to the play button, and sometimes it doesn’t respond to the previous/next track buttons either. It turns out to start streaming only by selecting a new track, for example, in a playlist.
This happens every time the amplifier is turned on, respectively, when it is detected as an available audio interface for Volumio
The Rotel is an integrated amplifier. Volume control should be handled by the Rotel. Are you saying if you set the mixer to none it doesn’t work?
(Keep in mind that noise doesn’t care about SW amplification. For example if your noise level is 1 dB and you set you SW volumue control to 4dB, 25% of the signal to your amplifier is noise. If you set the SW control to 100, it’s only 1%)
No, I play everything that is available to me now - flac files and YouTube music. Volumio, of course, does not control the volume; this is a task for an integrated amplifier.
Yesterday I was able to send an audio stream to the amplifier both in the “Hardware” mode and in the “None” mode mixer type - I just didn’t know how to start the streamer before… When pressing the “play” button there is no response from volume, but when pressing the “next” button track" or selecting another track there is a reaction.
Fine. I found out that the audio stream goes to the amplifier in any “Mixer type” modes. However, this only happens when selecting a new track or pressing the “next” track button (the latter does not always work).
I’ll tell you my user scenario:
The Volumio-based streamer is always on. The amplifier is turned off.
I turn on the amplifier or activate the PC-USB input
Volumio detects USB audio 2.0 device
The amplifier screen displays - “768K DSD”. At this moment, high-volume digital noise is heard from the acoustics (if the amplifier is set to a high volume level, the acoustics can be damaged - this is the main problem! ).
In the Volumio interface I press the “play” button - there is no reaction!
In the Volumio interface, I press the “next” track button - the amplifier display shows “44.1K PCM” and at this moment music sounds from the acoustics.
I tried turning off the amplifier when the music was playing, then turning it on again - in the Volumio interface the “play” button turns into “pause” and the track is played (the track time is counted), however in acoustics - digital noise is still heard until I select a new track or I’ll press the “next” track button.
Yes, by the way, the buttons for switching tracks, stop, pause, play when you press the amplifier remote control via the USB interface also do not work. At the same time, I only hear some sound distortion.
This is also strange… when connected to a PC, it usually works.
I think it has something to do with a state where and when Raspberry drops the syncsignal. As such, the remaining “input” to your Rotel is among others, just a shield noise from the USB cable itself. The RPi has for long been sensitive to rfi.
Let’s try something different:
The USB mode is an option in most of the Rotel model’s settings within the unit. I think setting the USB mode to 1.0 may solve the DSD static issue since DSD isn’t supported (if I recall correctly).
I have some suspicions about how well grounded the Rotel is and that it might be more susceptible to ground noise.
On the other hand, there is another option to employ USB purifiers like one made by iFi for USB audio.
If I select USB audio 1.0 in the amplifier settings, then there is no digital noise at all (at 100% volume there is only quiet noise from the audio path) - I tried turning the amplifier off and on several times.
However, I wanted to take advantage of USB audio 2.0. My version of the amplifier has an AKM4495SEC DAC (32 bit/768 kHz). And the asynchronous USB port is capable of receiving signals in PCM (up to 32 bit/384 kHz) and DSD64/DSD128 formats when connected to a computer.
The grounding in all sockets is good - the grounding loop is located on my territory.
Therefore, I conclude that when a USB device is detected, the driver in Linux does not provide it with a clock signal or something like that - I’m still new to these issues, so I don’t know exactly what’s going on there(
In the Volumio “Playback Options” you can switch “DSD Playback” mode to “DSD over PCM”, DSD streams will be encapsulated in 24 bits PCM.
Have you tested this option?
Just tried it. Exactly the same digital noise is observed as in the case of DSD Direct. The only thing is that for synchronization to appear and streaming to begin, you need to select another track (pressing the “play”, “next” and “previous” buttons does not lead to anything at all).
In my test, USB DACs like S.M.S.L, HiBY FC3/4, DANTE AVIOS USBA, EVO-SABRE, just to mention few, are not producing any noise artefacts. In all cases, I am using linear PSU to eliminate any noise from the power circuitry. Another area to check is the quality of the USB cable itself.
I believe that since in USB audio 1.0 mode there is no digital noise above normal, it means that the Linux driver in USB audio 2.0 mode does not work entirely correctly.
Fine. Do the play and previous/next track buttons on the control panels (or infrared remote control) of the DAC connected via USB work?
I am controlling track functions from Volumio. However you raised interesting question I will run test coming week.
Perhaps other community users have an existing experience - please chip in.
I tested directly attached DACs via USB and one have gave the volumio controls from the DAC’s remote, all other have not. Digging dipper, I did not see any remote requests being generated from other DACs I tested whilst debugging USB communication. Purely digital sound negotiation chat and payload.
Whilst looking into the technical specs, the DAC will need to follow standards with additional “hardware controlled” capabilities, and is purely driven by the DACs USB implementation.
To sum-up this discovery - the DAC’s USB will need to present as a hardware audio device, not just an audio device.
hello everyone: The solution is easier than all that… First of all, my solution only works with DACs not powered by USB power. Tested with Volumio installed on PC. You just have to remove the power pins of the USB connector (right and left ends) with some strips of insulating tape. thus canceling the passage of unnecessary and noisy current. luck . I recommend using 3m electrical tape to avoid problems with poor quality adhesive
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