Hi, probably an impossibility, but here goes. I have a Volumio Primo streamer that outputs digital audio on a USB (A) port, the flat one. I want to connect that to a PC to do some DSP before going to a DAC.
But a regular USB cable has the USB B (the squarish one) at the output side of the cable, and a PC doesn't have such an input, as far as I know. Is there a way to do what I want?
Tia for any pointers,
Jan
But a regular USB cable has the USB B (the squarish one) at the output side of the cable, and a PC doesn't have such an input, as far as I know. Is there a way to do what I want?
Tia for any pointers,
Jan
Not sure what you mean by "regular USB cable". You can get USB cables with whatever end connector you need. E.g. A to A, A to B, A to C
OK .... So then the question becomes: does a PC USB connector accept digital USB audio as input?
Jan
Jan
USB cables (or connectors) expect a stream of bits following the USB protocol. The cable or connector don't know anything about audio or video or whatever. On the PC side, its the drivers and/or the application that makes sense of what the stream of bits means. This may well boil down to what the program you intend to use for DSP expects/supports in the way of input - and then there's the output, since you want to go to a DAC.
Based on the manual USB audio output can be used to connect to a USB dac which probably means that Volumio acts as UAC2 host. Basic Windows UAC2 drivers cannot be used in this mode (PC as a UAC2 device). You would need a specific driver for this purpose.
PC can accept USB audio as input when PC is the UAC2 host. This is the same as using e.g. REW for recording ADC output.
In other words most software on PCs is designed to be a source not a receiver. Thr USB port itself goes both ways but the drivers and software on the PC have to be set up to get the stream not give it. That’s why your cable has a USB B on the end because that’s what is used on a receiving device like a DAC or such. You can find software and drivers for what you want to do but it’s not usually done the way you want to.
Jan, are you trying to implement an active crossover or room correction eq? I was just Googling around and there are EQ plugins available for Volumio to implement room correction. I see mention of "brutefir" and "fusiondsp". I don't have any experience with Volumio or the plugins so can't help you with you using them. Hopefully somebody with more experience with Volumio will chime in
Jan, that's impossible because of the USB bus topology. Any USB bus is a strict hierarchy with one, and only one, master (aka USB host) that initiates all data transfers, and one or more slaves (aka USB devices). Data transfers can be from the host to a device, or from a device to the host, but the host always is in control. A PC is a host, and Volumio, being a Linux distribution, is another host. You cannot connect two hosts together - that's the original reason for having USB A and B connectors.
Technically, some devices can switch between the roles of a host and a device - something called USB On-The-Go (OTG) - but these usually are mobile phones that act as a host if you connect e.g. a USB storage to them, and as a device if you connect them to a PC.
A possible workaround might be to have Volumio output digital audio not over USB but over S/PDIF or TOSLINK and to install on the PC a sound card with S/PDIF or TOSLINK inputs.
USB connectors are asymmetric because they carry power.
The PC can do everything that the streamer does. I don't see the point in using a streamer as a source for the PC.
Ed
The PC can do everything that the streamer does. I don't see the point in using a streamer as a source for the PC.
Ed
Ed that's probably the smart thing to do. I plan to get a miniPC to run JRiver and use its DSP functions, then go into a multichannel DAC.
I just like the Volumio a lot (I have two in different places), totally comfortable with the app on my phone and the mini iPad to run it.
Ohh well, I can always sell it when I have the JRiver stuff up and running.
Yes of course! I can connect my Umik digital mike to my PC and have REW listen to it. So that means that the PC accepts a digital audio input on a USB port!
So, all I need is a driver like the UAC2? I need to investigate whether JRiver supports that.
Jan
It won't work out of the box unfortunately. The Volumio is a USB host, denoted by the A connector. Your PC is a USB host. You can't plug two USB hosts together. The only way to make it work would be to switch the Volumio to device mode if it had a USB OTG / dual role capable port and load the appropriate Gadget driver.
http://trac.gateworks.com/wiki/linux/OTG
By standards - yes, but there are a lot of exceptions.
For example - "NVidia Shield Pro" has 2 USB-A connectors, usually acting as hosts. But one of them can be switched in the Shield settings to "device" (to connect to a PC).
P.S. If you in any case have PC with winb+JRiver, for what you need Volumio (on RPi?). Use JRiver also as the player, or install Album Player.
JRiver works fine as a Digital Crossover with multichannel USB DAC.
Using SPDIF output to connect to PC would be easiest provided your PC has spdif input. Volumio Primo does not have Toslink output.
Another possible way to use USB audio output would require 2 USB-I2S boards that have both I2S input & output. These would be connected in I2S loopback so you would have 2 USB ports both acting as UAC2 device. One for playback and one for recording.
Another possible way to use USB audio output would require 2 USB-I2S boards that have both I2S input & output. These would be connected in I2S loopback so you would have 2 USB ports both acting as UAC2 device. One for playback and one for recording.
I'm still intrigued how that UMIK mike works then. It sends USB audio into the PC USB port for REW.
Jan
Jan