Where Does Volume correction Occur

My chain looks like Qobuz->Roon(iMac)->Roon Plugin(rpi4 w/Volumio)->Topping E30->Sugden A21SE->Harbeth Compact 7.
When using the DSP in Roon with Convolution filter and looking at the chain display in Roon, it shows DSP volume after Volumio and before the E30. The DAC is in DAC only mode so no volume control there(although it shows “alsa”, the linux mixer on the rpi4 running Volumio underneath the E30).
Why isn’t it showing the Roon volume control(which is what I’m using) further up the chain in the Roon DSP section where it shows the Convolution filter processing?
Shouldn’t the Roon volume control happen in 64 bits right after that Convolution filter?

DSP volume is done on the endpoint not the core.

1 Like

So then I’m forced to use the low quality alsa mixer on the rpi to do volume if I want to use the roon interface to control it?

DSP volume is done via RAAT on the endpoint if its selected as the Volume control option in Roon. If it’s set as fixed it will output untouched as long as Volumio isn’t altering it. Roon has no other way to change volume of the device.

It’s also a 64bit operation.

1 Like

But it can only be 64 bit if the alsa mixer on the rpi is, right?
So the Topping E30 has 2 modes, preamp and pure dac. I have been running it in pure dac mode. I’m confused about how to use the supposed hardware volume capability of the dac and how that relates to the preamp mode. I have volume control in Volumio set to Hardware but no idea if it’s doing anything or whether the alsa mixer in linux is doing volume control.
Could Roon even instruct the hardware volume control in the dac to deal with volume?

No, with DSP volume in Roon, adjustment is done in the RAAT code before it is sent to ALSA. For hardware control I’m not sure. Depends if your E30 uses a standardized way or exposing it’s volume. It also depends on the OS used. I only have experience with RoPieee on my Pi devices.

1 Like

Thx. Something still seems unclear re DSP volume. When I use that option, the chain diagram still shows the volume change after Volumio( on the rpi4) but before the E30 DAC. If it was happening at the DSP level in the digital signal delivered over raat to the rpi4, why would it show in the chain between the rpi4 and the E30 DAC?

I had the same questions some time ago. Take a look at this thread: Device volume control

Perfect. Thx so much. So now the question is whether the roon plugin for Volumio is a “standard” roon bridge. Were you able to verify that for ropiee?

RoPieee is also just a Roon bridge. Only Roon Ready is tailored to devices. Usually commercial units with direct ethernet connection (wifi will also work). There are quite a few units with only digital out (USB, coax. AES/EBU…) that are Roon Ready, like dCS Network Bridge, Lumin U1/Mini or Sonore’s MicroRendu to name a few. But the free distros like RoPieee, Volumio, Dietpi and others are only allowed by Roon to use Roon bridge. Roon bridge is not even included in the distro image one downloads, but installed during setup or when selected for use.

I’ll check over on the Volumio site as to whether the roon plugin there conforms exactly to the roon bridge standards.

Just to follow up, I decide to switch to Ropieee and leave it at that. Thx

1 Like

There is only one Roon Bridge software, its compiled for different OS there is no standards as its all Roons code. Volumio just uses one for that distro of linux and arm hardware.

1 Like

Good choice.

Anything ever happen in dev re this post from last year?

It uses RAATs DSP on the endpoint to my knowledge which is 64bit. It then sends this on to Alsa for replay to DAC . They have not released a change to how it display yet in Signal path. Maybe in 1.8?