USB Audio -> STEREO <- LINE or MIC IN

[rec9140]

The Wolfson is a great little board, definitely adds some quality input to the devices... BUT

1) It sucks up the GPIO
2) Requies the P5 which in the new versionis gone, thus requires either a rework or will be dropped
3) Cirrus purchase of Wolfson, most likely is the death blow to the card as well
4) Drivers not modules, and thus not updating in the Raspbian distro as things are updated

Output is of no concern to me I don't use output from the board. All inputs are fed to an encoder software for other purposes.
So output quality is of no importance.

What I am after is a USB dongle that is similar all those $2 USB CMedia Dongles on various places.

OR

Something like the HifiBerry BUT AS INPUT DEVICE, again output is of no use for me AND GPIO PINS ARE ACCESSIBLE for my programs.

BUT

WITH *** STEREO ***, TRUE Left AND right inputs in prefered LINE LEVEL, but MIC will do as well.

All these $3 ones are MONO..

Prefer it with the CMedia 108 or other similar chipset and not the TP618 which has NO MIXER CONTROLS in ALSA due to the hardware.

Prefer it be LESS than $10/device.

Any one found something compatibale with Raspbian that has TRUE STEREO LINE or MIC INPUT?

Thanks in advance

[PiGraham]

I have this, or something that looks identical, and it works on my Pi with ALSA mixers controls.

http://www.ebay.co.uk/itm/USB-2-0-Exter ... 4d20a4a04c

[redhawk]

I bought a CM106 a few weeks ago they're usually going for 10 quid or less on eBay and yes with UK seller too (usually in a blue metallic box with SPDIF interfaces and many 3.5mm sockets).
To use with Raspbian make sure you have the latest kernel version installed via rpi-update otherwise audio may not work.
For recording stick to 48kHz, this applies to all USB capture devices as explained here - http://www.raspberrypi.org/forums/viewt ... 63&t=79402

For a cheap stereo capture capable device this is pretty good although I do have a slight DC offset on the microphone channel (only a minor inconvenience).

If you want something more up market I believe the Behringer UCA202 audio also works well with the Pi.

Richard S.

[rec9140]

Thanks to the replies...

But what I am after is something like these, in SHAPE and SIZE....

http://brain.pan.e-merchant.com/2/6/038 ... 865362.jpg

BUT WITH *** LINE LEVEL STEREO INPUT ***

I have several from Ebay BUT they are MONO and using it right now in several test cases.. but to use more than one requires a hub... and not compact..

The CM106, the large blue box, nice, but TOO BIG. Thanks. WAY TOOOOOO BIG...

Again, I don't really need output of any sort, SPIF etc.. but a LINE LEVEL STEREO or MIC STEREO INPUT is the important thing.

[redhawk]

Thanks to the replies...
But what I am after is something like these, in SHAPE and SIZE....

They don't exist, these ultra compact audio dongles are only capable of stereo headphones out, mono mic in.
Having a combined stereo line-in and mono jack on the same physical socket would add serious complexity to the circuit not to mention added cost to implement it.

For what it's worth the CM106 is pretty small (close to Pi board dimensions and half the size of a Sound Blaster Live 24bit), yes it has other features like SPDIF but more importantly it does stereo line-in capture.
It also worth nothing the box connects via a Mini USB cable rather than directly into the USB port this means it won't physically block the other USB port as can happen with the other basic audio dongles.

Richard S.

[rec9140]

Having a combined stereo line-in and mono jack on the same physical socket would add serious complexity to the circuit not to mention added cost to implement it.

Thanks, but if it did ONE or the OTHER LINE IN or MIC IN but stereo I would be happier...

For what it's worth the CM106 is pretty small (close to Pi board dimensions and half the size of a Sound Blaster Live 24bit), yes it has other features like SPDIF but more importantly it does stereo line-in capture.

Thanks, but the goal is COMPACT, nothing external, neat and tidy....

The Wolfson fits that to a point, but:

1) HOGS the GPIO port

2) HOGS the GPIO PINS
2a) Requires giving up the serial UART to get GPIO pins, but I need that serial port for something else.

3) Possibly doesn't play well with other devices on I2C bus, if you could find a way to add them

4) For #3 would require a HUGE MANUAL HACK to the board for each device we build ie: desolder that GPIO connector, put in one that would allow stacking. R&D, testing.. sourcing, added cost parts, labor to desolder, install etc..

5) Wolfson in current form is deprecated. How... well I can see the writing on the wall MCM/Newark are pushing heavily the B+ Br3, which the Wolfson is NOT COMPATIBLE with. The Br2 is on back order at most, so I can see where this is headed regardless of statements that the Br2 will continue, the sellers are going to kill it off to simplfy their inventory. Yeah there was mention in passing that there would be Br3 Wolfson... I'll believe it when I see it. And if this was the case, I would think that a company so tied into this board would have been given notice and time to develop the replacement to launch with the Br3.

6) Wolfson v. Raspbian and driver squabble

7) Wolfson & CMedia purchase.. This doesn't really fit in to CMedia's plans in my opinion. If Wolfson is left alone and autonomous, yeah right, maybe...

8) Wolfson costs as much as the board itself just to get LINE IN/MIC IN.. the output is of no use to me, could care less. The filtering on the Wolfson might be of interest if some one would put out some info on how to use them. And by info not some gobbleygook of ALSAese.. That is great if you developed ALSA and the board... How about something for us mere mortals. I develop a lot of things, but ALSA is not one of them.. It is about like me talking about EDACS, P25, LTR etc. to these people they will be in over their depth quickly. Well same here.

It also worth nothing the box connects via a Mini USB cable rather than directly into the USB port this means it won't physically block the other USB port as can happen with the other basic audio dongles.

I am not so much worried about them blocking the ports, but if I use USB dongles then the case has to be developed to enclose all that. Same with the CM106 it would have to hold in all that and only expose the Line In port....

[Pander]

I am looking for an ADC for line in and microphones on GPIO. It needs to be high quality in terms of 24-bit and 96 kHz. All I can find for B+ is the Cirrus Wolfson card or are there any alternatives?

There is a lot of scattered information on the Wolfson card and some worrying information about drivers. If this is the card to use, could it get a wiki page somewhere with:

• hardware specifications
• drivers source code and updates for RPi kernel (such as https://github.com/raspberrypi/linux/pull/625)
• how to configure the card (also for cases where audio over RPi HDMI should not be disabled and this card is used only for audio input)
• example usage (tips and tricks with GNU/Linux command line tools)
• contact information at Wolfson (such as bottom of http://www.element14.com/community/thre ... -pi-kernel)

[DougieLawson]

The Wolfson card WON'T WORK on a Raspberry Pi A+ or B+. The P5 header is removed on the A+/B+.

Take a look at the HiFiBerry or USB sound devices.

[PeterO]

I am looking for an ADC for line in and microphones on GPIO. It needs to be high quality in terms of 24-bit and 96 kHz. All I can find for B+ is the Cirrus Wolfson card or are there any alternatives?

I'm using one of these on a B+

http://skpang.co.uk/catalog/pcm1803a-an ... p-697.html

PeterO

[Pander]

The Wolfson card WON'T WORK on a Raspberry Pi A+ or B+. The P5 header is removed on the A+/B+.

Take a look at the HiFiBerry or USB sound devices.

So it is true that https://nl.farnell.com/webapp/wcs/store ... reId=10168 which should fit on a B+ and not on a B isn't working because of http://www.element14.com/community/mess ... -pi-kernel ? It has different GPIO pins. Thanks for the suggestions. HiFiBerry has no audio in as far as I could see.

[DougieLawson]

Your URLs got mushed.

http://www.element14.com/community/thre ... p5-missing

It uses eight sprung connectors to connect to the P5 header. The P5 header has been removed on the A+ & B+. There's no way to get my Wolfson card running on my A+.

[Pander]

I'm using one of these on a B+

http://skpang.co.uk/catalog/pcm1803a-an ... p-697.html

PeterO

Thanks PeterO. What are good guides to get started with this one? I have found https://www.sparkfun.com/products/9365 http://www.peteronion.org.uk/I2S/ and http://blog.koalo.de/2013/05/i2s-suppor ... ry-pi.html so far. Are these the places to be to get this working on B+?

[Pander]

Your URLs got mushed. ...

URLs:
Board designed for B+ https://nl.farnell.com/webapp/wcs/store ... reId=10168 https://nl.farnell.com/webapp/wcs/store ... reId=10168
Discussion http://www.element14.com/community/mess ... -pi-kernel http://www.element14.com/community/mess ... -pi-kernel

[PeterO]

I'm using one of these on a B+

http://skpang.co.uk/catalog/pcm1803a-an ... p-697.html

PeterO

Thanks PeterO. What are good guides to get started with this one? I have found https://www.sparkfun.com/products/9365 http://www.peteronion.org.uk/I2S/ and http://blog.koalo.de/2013/05/i2s-suppor ... ry-pi.html so far. Are these the places to be to get this working on B+?

The most useful link is the one on my page... http://www.raspberrypi.org/forums/viewt ... 75#p604231

I had some pm with plugh and he said he was working on a new version of his "loader", but I've not seen anything appear yet.

Note that the board (and the codec it carries) are pretty "dumb" in that there are no configurable features like input selection,gain control etc etc. You may need some external analogue signal processing (amplification and low pass filtering) to get the best results.

PeterO

[Pander]

Thanks. You mean a microphone such as https://www.modmypi.com/adafruit-electr ... -amplifier or https://www.modmypi.com/adafruit-MAX981 ... ifier-1713 ?

[Richard-TX]

Here is what you likely want.

http://www.amazon.com/Behringer-302USB- ... B005EHILV4

USB in-out
Line and mic in
Phantom power
stereo
headphone out
big bang for the buck ($50)

I have been running one for almost two years with my Rpi. Performance has been flawless,

[PeterO]

Thanks. You mean a microphone such as https://www.modmypi.com/adafruit-electr ... -amplifier or https://www.modmypi.com/adafruit-MAX981 ... ifier-1713 ?

No. They are microphones and amplifiers on the one board. You will have to compare your available signal level with the input spec of the codec to work out how much amplification (or may be attenuation) you need to provide.

PeterO

[Pander]

I am more tempted to http://www.minidsp.com/products/acousti ... ent/umik-1 now by the lack of a properly working and supported ADC with line in or microphones for B+. Experimental solutions are good but not for my application. And this device is calibrated as well.

[Orbital6]

I am looking for an ADC for line in and microphones on GPIO. It needs to be high quality in terms of 24-bit and 96 kHz. All I can find for B+ is the Cirrus Wolfson card or are there any alternatives?

I'm using one of these on a B+

http://skpang.co.uk/catalog/pcm1803a-an ... p-697.html

PeterO

I take it this provides i2s audio input? If so, are you connecting the 3/4 i2s wires to p5 on the pi? I've got a toshiba chip that isolates HDMI audio and passes it through an i2s bus. I've been wondering if i can pass that to the pi's i2s bus (so i2s input on the rpi) and play with the audio that way (audio out on the minijack/web stream). But i'm stuck on the software side. How did you setup your i2s audio input?

[Pander]

I went for the UMIK-1 and that works like a charm.