Edirol UA-25EX

UA-25EX

Vendor Link: http://www.roland.com/products/en/UA-25EX/

The Edirol UA-25EX is a good quality audio device, with great features:

Variety of Input & Output options
Balanced Input & Output
Two Professional Grade Mic Preamps
Built-in Analog Compresser & Limiter
Zero-Latency, Direct Monitoring
USB Bus-Powered
Phantom microphone power (48 volts)
Full-duplex management
MIDI I/O

The Edirol UA-25EX is similar in every point to the Edirol UA-25 with the addition of an analog compressor. This device has 2 modes:

Standards-compliant: the device is recognised by the snd_usb_audio module and you can play and record at 44.1kHz and 16-bit samples. MIDI is not supported in this mode.
Advanced mode: full support for 24-bit playback, recording at rates up to 96 kHz, and MIDI.

The computer has little control over various settings like Input level, Output level, mixing and even sample rate. This is a hardware issue, and will apply equally to this card on all OS'es. Some users may like this old-fashion way to manage sound cards, other may dislike it. To mitigate this limitation, Alsa offers a variety of features and plugins which emulate at software level the missing features. This is the advantage of Alsa over other sound systems.

1 Understanding the Edirol UA-25EX logic
2 Basic Alsa configuration
3 Advanced Alsa configuration
4 MIDI configuration
5 Resulting .asoundrc file
6 Device information

Understanding the Edirol UA-25EX logic

At first, you should have a look at the back pane. Or look at the photo of the device. Try to locate three important buttons:

Advance button

On the back pane of the UA-25EX, there is a switch button called "ADVANCE", which controls the USB mode of the device. The switch has two values: ON and OFF:

In advance mode (ADVANCE button ON), the UA-25EX can record or play sound in native 24 bits, in either 44.100 Hz, 48.000 Hz or 96.000 Hz sample rates. You can choose sample rates using a button. At 96 Khz, the device is either capture or playback only. MIDI is enabled. Advance mode is recognised since Alsa 1.0.7.
In normal mode (ADVANCE button OFF), the UA-25EX is fully USB sound compliant. It records at the rate of 44.100 Hz, in 16 bits, and is full- duplex. MIDI is disabled.

Sample rates switch

On the back pane of the UA-25EX, there is a switch button called "SAMPLE RATE". The switch has three values: 44.1 Khz, 48 Khz and 96 Khz:

In Advance mode OFF, the device will always record/play natively at the rate of 44.1 Khz using 16 bits.
In Advance mode ON, the device will be able to record using 24 bits. Choose the sample rate using the SAMPLE RATE switch:
- 44.1 Khz: play and record at the same time,
- 48 Khz: play and record at the same time,
- 96 Khz: play OR record. Press the REC/PLAY button to choose.

REC/PLAY button

When in Advance mode ON, at 96 Khz, you can either play OR record. Press the REC/PLAY button to choose.

Cold/Hot reboot

Whenever you switch from ADVANCE ON to ADVANCE OFF, or change sample rates, you will either need to:

cold reboot: Unplug the USB cord, plug it again. The hotplug mechanism will remove all snd modules and will reload them. Be warned: frequent plug/unplug may harm the device physical contacts.
shutdown/reboot your computer: it is the recommended way, as it will not harm your device (or the USB cord). Your computer might not turn off the USB power unless you shut down completely. A good place to switch the Advance button is during the grub menu, if you are using grub, and if that fails, shut the computer off completely to switch the Advance button.

Lost?

To understand advance mode, sample rates and REC/PLAY, it is recommended to use aplay and arecord in verbose (option -v) mode. This is what we will do during the howto. This will clearly show you how the audio devices plays and records sound.

Basic Alsa configuration

alsaconf is not required to use the Edirol UA-25EX. Hotplug is able to recognise the audio device. Just plug and play.

Assigning audio system rights

To play sound, you need audio system rights. To query your systems rights:

$ groups
my_username adm disk dialout fax cdrom floppy tape dip video plugdev powerdev scanner

In this example, I don't have enough rights to play/record sound. To assign rights: Become root (system administrator):

$ su
Password:

Enter the administrator password and then:

# adduser my_username audio

Will add the user my_username (replace with your username) to the audio group. After logging out and back in again, you should be able to play music.

Naming the Edirol UA-25EX device

If the UA-25EX is the only device of your computer, you can address the device using the plughw:0,0, but it is not very convenient. We recommend using the alphanumeric name of the device. To query the name of your device, type:

$ cat /proc/asound/cards
 0 [UA25EX         ]: USB-Audio - EDIROL UA-25EX
                     Roland EDIROL UA-25 at usb-0000:00:0b.0-2, full speed
 1 [Audio          ]: USB-Audio - USB Audio
                     USB Audio at usb-0000:00:0b.1-4.4.3, full speed

Here, you should use plughw:UA25EX rather than plughw:0,0

Testing sound output

Test the card output. This command plays a womans voice on 2 channels ("Front Right", "Front Left"):

speaker-test -c2 -D plughw:UA25EX -twav

Playing sound

In the following example, Advance button is set to ON, and sample rate is 48 Khz. Do not forget to cold/hot reboot whenever you change settings. To play a sound:

$ aplay -D plughw:UA25EX foo.wav

For a better understanding, it is recommended to play in verbose mode:

$ aplay -v -D plughw:UA25EX foo.wav

The following message is displayed:

Playing raw data 'foo.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

Plug PCM: Rate conversion PCM (48000, sformat=U8) Its setup is:

 stream       : PLAYBACK
 access       : RW_INTERLEAVED
 format       : U8
 subformat    : STD
 channels     : 1
 rate         : 8000
 exact rate   : 8000 (8000/1)
 msbits       : 8
 buffer_size  : 4000
 period_size  : 1000
 period_time  : 125000
 tick_time    : 0
 tstamp_mode  : NONE
 period_step  : 1
 sleep_min    : 0
 avail_min    : 1000
 xfer_align   : 1000
 start_threshold  : 4000
 stop_threshold   : 4000
 silence_threshold: 0
 silence_size : 0
 boundary     : 262144000

Slave: Route conversion PCM (sformat=S24_3LE)

Transformation table:
   0 <- 0
   1 <- 0

Its setup is:

 stream       : PLAYBACK
 access       : MMAP_INTERLEAVED
 format       : U8
 subformat    : STD
 channels     : 1
 rate         : 48000
 exact rate   : 48000 (48000/1)
 msbits       : 8
 buffer_size  : 24006
 period_size  : 6000
 period_time  : 125000
 tick_time    : 0
 tstamp_mode  : NONE
 period_step  : 1
 sleep_min    : 0
 avail_min    : 6000
 xfer_align   : 6000
 start_threshold  : 24000
 stop_threshold   : 24006
 silence_threshold: 0
 silence_size : 0
 boundary     : 1573257216

Slave: Hardware PCM card 1 'UA-25EX' device 0 subdevice 0 Its setup is:

 stream       : PLAYBACK
 access       : MMAP_INTERLEAVED
 format       : S24_3LE
 subformat    : STD
 channels     : 2
 rate         : 48000
 exact rate   : 48000 (48000/1)
 msbits       : 24
 buffer_size  : 24006
 period_size  : 6000
 period_time  : 125000
 tick_time    : 0
 tstamp_mode  : NONE
 period_step  : 1
 sleep_min    : 0
 avail_min    : 6000
 xfer_align   : 6000
 start_threshold  : 24000
 stop_threshold   : 24006
 silence_threshold: 0
 silence_size : 0
 boundary     : 1573257216

The sound file is 8.000 Hz sample rate over 8 bits. Alsa converts it to 48.000 Hz over 24 bits... and plays the sound. When playing two sounds at the same time, an error message is displayed:

$ aplay: main:550: audio open error: Device or resource busy

Remember, in advance mode, the UA-25EX is only half-duplex.

Recording sound

In this example, the UA-25EX device is set to Advance ON and 96 Khz recording. REC button is pressed. You can use arecord utility, which is part of Alsa package, to record any sound from the microphone:

$ arecord -r 96000 -f cd -t wav -D plughw:UA25EX foobar.wav

For a better understanding, try the same command in verbose mode:

$ arecord -v -r 96000 -f cd -t wav -D plughw:UA25EX foobar.wav

The resulting message:

Recording WAVE 'foobar.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, \
Stereo Plug PCM: Rate conversion PCM (96000, sformat=S24_3LE)

Its setup is:

stream            : CAPTURE
access            : RW_INTERLEAVED
format            : S16_LE
subformat         : STD
channels          : 2
rate              : 44100
exact rate        : 44100 (44100/1)
msbits            : 16
buffer_size       : 22050
period_size       : 5512
period_time       : 125000
tick_time         : 0
tstamp_mode       : NONE
period_step       : 1
sleep_min         : 0
avail_min         : 5512
xfer_align        : 5512
start_threshold   : 1
stop_threshold    : 22050
silence_threshold : 0
silence_size      : 0
boundary          : 722534400

Slave: Hardware PCM card 1 'UA-25EX' device 0 subdevice 0

Its setup is:

stream            : CAPTURE
access            : MMAP_INTERLEAVED
format            : S24_3LE
subformat         : STD
channels          : 2
rate              : 96000
exact rate        : 96000 (96000/1)
msbits            : 24
buffer_size       : 48002
period_size       : 12000
period_time       : 125000
tick_time         : 0
tstamp_mode       : NONE
period_step       : 1
sleep_min         : 0
avail_min         : 12000
xfer_align        : 12000
start_threshold   : 2
stop_threshold    : 48002
silence_threshold : 0
silence_size      : 0
boundary          : 1572929536

The Edirol UA-25EX is able to record in 24 bits, at the sample rate of 96 Khz. Now, try to play the recorded sound at 96 Khz:

$ aplay -v -D plughw:UA25EX foobar.wav
$ aplay: main:550: audio open error: No such file or directory

At 96.000 Hz, the audio device can play OR record, but not both. Now, switch the PLAY button. Unplug the USB cord and plug it again. This should initialize Alsa if you are using Udev and hotplug. Re-try to play the sound:

$ aplay -v -D plughw:UA25EX foobar.wav

This results in:

Playing WAVE 'foobar.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
Plug PCM: Rate conversion PCM (96000, sformat=S24\_3LE)

Its setup is:

stream            : PLAYBACK
access            : RW_INTERLEAVED
format            : S16_LE
subformat         : STD
channels          : 2
rate              : 44100
exact rate        : 44100 (44100/1)
msbits            : 16
buffer_size       : 22050
period_size       : 5512
period_time       : 125000
tick_time         : 0
tstamp_mode       : NONE
period_step       : 1
sleep_min         : 0
avail_min         : 5512
xfer_align        : 5512
start_threshold   : 22048
stop_threshold    : 22050
silence_threshold : 0
silence_size      : 0
boundary          : 722534400

And:

Slave: Hardware PCM card 1 'UA-25EX' device 0 subdevice 0

Where its setup is:

stream            : PLAYBACK
access            : MMAP_INTERLEAVED
format            : S24_3LE
subformat         : STD
channels          : 2
rate              : 96000
exact rate        : 96000 (96000/1)
msbits            : 24
buffer_size       : 48002
period_size       : 12000
period_time       : 125000
tick_time         : 0
tstamp_mode       : NONE
period_step       : 1
sleep_min         : 0
avail_min         : 12000
xfer_align        : 12000
start_threshold   : 48000
stop_threshold    : 48002
silence_threshold : 0
silence_size      : 0
boundary          : 1572929536

It works! Remember, at 96.000 Khz, you can either play OR record, but not both.

Advanced Alsa configuration

The recommended settings in this HOWTO are now:

Advance mode : ON
Sample rate : 44,1 Khz

This will record/play sound in 24 bits, at the frequency of 44.100 Hz.

Full-duplex mode

As mentioned above, the Edirol UA-25EX supports full-duplex operation, except at 96 Khz.If you want to play and record in full-duplex though half- duplex plugins, check out the asym plugin, which is able to combine the dmix (i.e. play) and dsnoop (i.e. record) plug-ins.

Custom softvol PCM

Using mixer settings on card 0 will return:

$ alsamixer -c 0
no mixer elems found

Unfortunately these is no software control over the hardware mixers on the device (like in any USB device), nothing will show up in mixer programs. Fortunately, Alsa offers the softvol plugin to create a software volume control. We will also define this control as the default mixer. Here is my first try:

pcm.!default {
    type plug
    slave.pcm "softvol"
}
pcm.softvol {
    type softvol
    slave {
        pcm "pasymed"
    }
    control {
        name "SoftMaster"
        card 0
    }
}

Let us have a look at our software mixer:

$ amixer
Simple mixer control 'SoftMaster',0
Capabilities: volume
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 255
Front Left: 255 [100%]
Front Right: 255 [100%]

Recording left and right input channels seperately

When recording from two mono inputs (Input 1/L and Input 2/R), the sound is mixed into a stereo stream at hardware level. Again, there is no software control over this audio device. This is a problem when you only record from one mono microphone. The resulting stereo sound includes a muted channel with noise. At software level, you may downmix this sound to mono, but this degrades quality because of the muted channel with noise. A simple solution is to record from left and right input channels seperately, as explained in the dsnoop howto.

pcm.record_left {
    type dsnoop
    ipc_key 234884
    slave {
        pcm "plughw:UA25EX"
        channels 2
    }
    bindings.0 0
}
pcm.record_right {
    type dsnoop
    ipc_key 2241234
    slave {
        pcm "plughw:UA25EX"
        channels 2
    }
    bindings.0 1
}

Digital signals

The same rules apply here. Alsa has very little control over the UA-25EX hardware. Digital control is done using buttons on the front pane.

Digital In

To record from digital source, press the "DIGITAL IN" button on the front pane of the UA-25EX. This is simple as that! You can then record using any Alsa tool, on the pasymed or SoftMaster PCMs.

Digital Out

Here, the Edirol UA-25EX is in Advance mode off. It provides 16 bits, 44.100 Hz digital output.

Let us try Alsa utility speaker-test:

$ speaker-test -c 2 -D softvol0 -twav

An optical cable is connected:

from Edirol UA-25EX Digital out
to a Terratec USB Aureon MK-2 digital in.

In the mixer of the Terratec Aureon, I select Input 2 and check IEC958 In. I can record the digital stream using the following command:

$ arecord -v -f S16_LE -c 2 -D plughw:1,0 foobar.wav

I can record the digital out stream of the Edirol UA-25EX without problem.

MIDI configuration

For MIDI to work, the device has to be in advance mode. If MIDI is working, you should see a "raw midi" device for the UA-25EX in /proc/asound/devices:

$ grep midi /proc/asound/devices
  8: [ 0- 0]: raw midi

Also, /proc/asound/card0/midi0 should exist (assuming the UA-25EX is the 0th audio device):

$ cat /proc/asound/card0/midi0
UA-25EX

Output 0
  Tx bytes     : 0
Input 0
  Rx bytes     : 0

MIDI ports

If the UA-25EX is running in advance mode, aconnect should show one MIDI input and one MIDI output port:

$ aconnect -il                    # list readable MIDI ports
client 16: 'UA-25EX' [type=kernel]
    0 'UA-25EX MIDI 1    '

$ aconnect -ol                    # list writable MIDI ports
client 16: 'UA-25EX' [type=kernel]
    0 'UA-25EX MIDI 1    '

If you prefer a graphical interface, check out aconnectgui. The relevant information can also be found in /proc/asound/seq/clients.

Connecting an external MIDI controller

To connect an external MIDI controller (e.g. keyboard, faderbox, stompbox, etc.), just plug its MIDI output into the "MIDI IN" socket on the back of the UA-25EX, and use aconnect to connect it to whatever software synth you want to interpret the MIDI data. To connect my MIDI foot controller to PureData, aconnect shows me the following (among other things):

$ aconnect -il
client 16: 'UA-25EX' [type=kernel]
    0 'UA-25EX MIDI 1    '

$ aconnect -ol
client 128: 'Pure Data' [type=user]
    0 'Pure Data Midi-In 1'

To get MIDI data flowing from my foot controller into PureData, the incantation I need is:

$ aconnect 16:0 128:0

Connecting an external MIDI synthesizer

I don't have one, but the process ought to be entirely analogous to that described in the preceding section. Feel free to contribute your own experiences.

Resulting .asoundrc file

For clarity, here is the resulting .asoundrc file:

pcm.!default {
  type             plug
  slave.pcm       "softvol"
}
pcm.softvol {
  type            softvol
  slave {
      pcm         "pasymed"
  }
  control {
      name        "SoftMaster"
      card        0
  }
}
#This PCM combining the dmix and dsnoop slaves
pcm.asymed {
     type asym
     playback.pcm "dmix"
     capture.pcm "dsnoop"
}
#This PCM should be able to convert recording rates automatically
pcm.pasymed {
     type plug
     slave.pcm "asymed"
}
pcm.record_left {
  type        dsnoop
  ipc_key 234884
  slave {
      pcm     "plughw:UA25EX"
      channels 2
  }
  bindings.0  0
}
pcm.record_right {
  type        dsnoop
  ipc_key 2241234
  slave {
      pcm     "plughw:UA25EX"
      channels 2
  }
  bindings.0  1
}

Device information

The following section may help Alsa hackers (please ignore the references to my second soundcard HDA Intel):

cat/proc/bus/usb/devices

$ cat/proc/bus/usb/devices
 T:  Bus=02 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  5 Spd=12  MxCh= 0
 D:  Ver= 1.10 Cls=ff(vend.) Sub=00 Prot=ff MxPS= 8 #Cfgs=  1
 P:  Vendor=0582 ProdID=00e6 Rev= 1.00
 S:  Manufacturer=Roland
 S:  Product=EDIROL UA-25EX
 C:* #Ifs= 3 Cfg#= 1 Atr=80 MxPwr=480mA
 I:* If#= 0 Alt= 0 #EPs= 0 Cls=ff(vend.) Sub=02 Prot=00 Driver=snd-usb-audio
 I:  If#= 0 Alt= 1 #EPs= 1 Cls=ff(vend.) Sub=02 Prot=00 Driver=snd-usb-audio
 E:  Ad=01(O) Atr=09(Isoc) MxPS= 320 Ivl=1ms
 I:* If#= 1 Alt= 0 #EPs= 0 Cls=ff(vend.) Sub=02 Prot=00 Driver=snd-usb-audio
 I:  If#= 1 Alt= 1 #EPs= 1 Cls=ff(vend.) Sub=02 Prot=00 Driver=snd-usb-audio
 E:  Ad=82(I) Atr=05(Isoc) MxPS= 320 Ivl=1ms
 I:  If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=03 Prot=00 Driver=snd-usb-audio
 E:  Ad=03(O) Atr=02(Bulk) MxPS=  32 Ivl=0ms
 E:  Ad=84(I) Atr=02(Bulk) MxPS=  32 Ivl=0ms
 I:* If#= 2 Alt= 1 #EPs= 2 Cls=ff(vend.) Sub=03 Prot=00 Driver=snd-usb-audio
 E:  Ad=03(O) Atr=02(Bulk) MxPS=  32 Ivl=0ms
 E:  Ad=84(I) Atr=03(Int.) MxPS=  32 Ivl=1ms

cat /proc/asound/devices

$ cat /proc/asound/devices
 0: [ 0]   : control
 1:        : sequencer
16: [ 0- 0]: digital audio playback
17: [ 0- 1]: digital audio playback
24: [ 0- 0]: digital audio capture
32: [ 1]   : control
33:        : timer
40: [ 1- 0]: raw midi
48: [ 1- 0]: digital audio playback
56: [ 1- 0]: digital audio capture

cat /proc/asound/cards

$ cat /proc/asound/cards
0 [Intel          ]: HDA-Intel - HDA Intel
                     HDA Intel at 0xd8240000 irq 22
1 [UA25EX         ]: USB-Audio - UA-25EX
                     EDIROL UA-25EX at usb-0000:00:1d.0-2, full speed

aplay -l

$ aplay -l

**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: Conexant Digital [Conexant Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: UA25EX [UA-25EX], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

aplay -L

$ aplay -L

default:CARD=Intel
  HDA Intel, CONEXANT Analog
  Default Audio Device
front:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  Front speakers
surround40:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  4.0 Surround output to Front and Rear speakers
surround41:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Intel,DEV=0
  HDA Intel, CONEXANT Analog
  7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
null
  Discard all samples (playback) or generate zero samples (capture)
default:CARD=UA25EX
  UA-25EX, USB Audio
  Default Audio Device
front:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  Front speakers
surround40:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  4.0 Surround output to Front and Rear speakers
surround41:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=UA25EX,DEV=0
  UA-25EX, USB Audio
  IEC958 (S/PDIF) Digital Audio Output

GITHUB | EDIT

Edirol UA-25EX

Contents

Understanding the Edirol UA-25EX logic

Advance button

Sample rates switch

REC/PLAY button

Cold/Hot reboot

Lost?

Basic Alsa configuration

Assigning audio system rights

Naming the Edirol UA-25EX device

Testing sound output

Playing sound

Recording sound

Advanced Alsa configuration

Full-duplex mode

Custom softvol PCM

Recording left and right input channels seperately

Digital signals

Digital In

Digital Out

MIDI configuration

MIDI ports

Connecting an external MIDI controller

Connecting an external MIDI synthesizer

Resulting .asoundrc file

Device information

cat/proc/bus/usb/devices

cat /proc/asound/devices

cat /proc/asound/cards

aplay -l

aplay -L