By default, the 2496 does not work well with ubuntu.

Here's a workaround:

- Edit /lib/udev/rules.d/90-pulseaudio.rules and add the line:

SUBSYSTEMS=="pci", ATTRS{vendor}=="0x1412", ATTRS{device}=="0x1712", ATTRS{subsystem_vendor}=="0x1412", ATTRS{subsystem_device}=="0xd634", ENV{PULSE_PROFILE_SET}="m_audio-audiophile-2496.conf"

- Create said file /usr/share/pulseaudio/alsa-mixer/profile-sets/m_audio-audiophile-2496.conf:

# This file is part of PulseAudio.
#
# PulseAudio is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of the
# License, or (at your option) any later version.
#
# PulseAudio is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with PulseAudio; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

; M-Audio Delta Audiophile 2496
;
; This card, based on the Via ICE1712 chipset, has two stereo audio channels
; (1 in and 1 out) and a separate S/PDIF digital stereo channel. Like with
; all ICE1712-based cards, this is exposed by ALSA as a single 10-channel
; device with some of the channels not connected.
;
; See default.conf for an explanation on the directives used here.

[General]
auto-profiles = no

[Mapping analog-stereo-in]
description = Analog Stereo Input
device-strings = hw:%f,0
channel-map = front-left,front-right,aux0,aux1,aux2,aux3,aux4,aux5,aux6,aux7,aux8,aux9
direction = input

[Mapping analog-stereo-out]
description = Analog Stereo Output
device-strings = hw:%f,0
channel-map = front-left,front-right,aux0,aux1,aux2,aux3,aux4,aux5,aux6,aux7
direction = output

[Mapping analog-digital-stereo-out]
description = Analog/Digital Stereo Output
device-strings = hw:%f,0
channel-map = front-left,front-right,aux0,aux1,aux2,aux3,aux4,aux5,front-left,front-right
direction = output

[Mapping digital-stereo-out]
description = Digital Stereo Output
device-strings = hw:%f,0
channel-map = aux0,aux1,aux2,aux3,aux4,aux5,aux6,aux7,front-left,front-right
direction = output

[Mapping digital-stereo-in]
description = Digital Stereo Input
device-strings = hw:%f,0
channel-map = front-left,front-right,front-left,front-right,front-left,front-right,front-left,front-right,front-left,front-right,front-left,front-right
direction = input

[Mapping digital-stereo]
description = Digital Stereo Input/Output
#device-strings = hw:%f,1
device-strings = iec958:%f
channel-map = left,right
direction = any

[Profile output:stereo]
description = Analog Stereo Output
output-mappings = analog-stereo-out
input-mappings =
priority = 80
skip-probe = yes

[Profile output:stereo-da+input:stereo-analog]
description = Analog Stereo Input/Output
output-mappings = analog-stereo-out
input-mappings = analog-stereo-in
priority = 100
skip-probe = yes

[Profile output:stereo-da+input:stereo-analog]
description = Analog Stereo Input/Output, Digital Stereo Output
output-mappings = analog-digital-stereo-out
input-mappings = analog-stereo-in
priority = 90
skip-probe = yes

[Profile output:spdif]
description = Digital Stereo Output (Analog Disabled)
output-mappings = digital-stereo-out
input-mappings = 
priority = 60
skip-probe = yes

[Profile output:spdif+input:spdif]
description = Digital Stereo Input/Output (Analog Disabled)
output-mappings = digital-stereo-out
input-mappings = digital-stereo-in
priority = 70
skip-probe = yes

------------------------------------

And add the following to 
/etc/pulse/default.pa:

# Workaround for MAudio Audiophile
# https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/178442/comments/7
load-module module-alsa-sink sink_name=M2496_out device=hw:M2496
format=s32le channels=10
channel_map=left,right,aux0,aux1,aux2,aux3,aux4,au x5,aux6,aux7
load-module module-alsa-source source_name=M2496_in device=hw:M2496
format=s32le channels=12
channel_map=left,right,aux0,aux1,aux2,aux3,aux4,au x5,aux6,aux7,aux8,aux9