All Delta cards contain a 36-bit embedded DSP enabling a software-driven patchbay/router for all analog and digital I/O—all with extremely fast throughput for low-latency software monitoring.  It accepts digital audio streams from all hardware inputs and all outgoing software audio devices, mixes them with 36-bit internal precision and then provides the mixed output to one or more locations.  For the purpose of monitoring, the output of the mixer may be routed to the first set of analog outputs (OUT1/OUT2 as a stereo pair) and/or the S/PDIF digital output (if available).  This guide will provide of a brief overview of the new Delta Series control panel for Windows XP Service Pack 3 and Windows Vista (32 bit).

The Delta Control Panel can be accessed from the Windows Control Panel



or by right-clicking the M-Audio icon in the system tray:




The Mixer page

The Mixer page (labeled Monitor Mixer in previous driver versions) controls the digital mixer built into the Delta's PCI controller chip.  The output of this mixer may be assigned to the OUT1/OUT2 analog outputs and/or the S/PDIF Out digital output (this selection is made on the Output page).  At the left side of the Mixer page, you will see the Master Volume fader. This fader controls the overall stereo level of the mixer output.


Note: The Delta Audiophile 192 does not have a Master Volume slider

The dark gray channels accept hardware audio streams directly from the Delta's analog and digital input ports (pictured above), and software audio streams (digital audio generated in software to be output, pictured below).  This combination of streams makes the monitor mixer extremely flexible.  Each mixer input channel has its own level fader and may be panned anywhere in the left/right stereo field.  Each input also has its own peak meter.  The peak meters indicate the incoming "pre-fader" levels of the incoming audio and are therefore not affected by the fader settings.  However, the input faders do affect the levels of the signals exiting the mixer and you will see the affect of the input faders on the output "Master Volume" peak meters.  Because of the large number of mixer inputs, not all inputs are displayed simultaneously.  You may use the scroll bar at the bottom of the Delta Control Panel to scroll the view left or right (see below).




The Input page

On the new Input page are the variable signal level controls for the analog inputs*; these controls were formerly located on the Hardware Settings page of previous driver versions.  The selections are labeled “+4dBu,” “Con” (-4dB), and “-10dBV.”


* Note: Delta 44, 66, & 1010lt only 

This provides versatile control of your input operating line levels.  The default +4dBu setting will give the most headroom for recording, allowing the Delta card to accept a hotter signal level.  Consumer (abbreviated Con) is a good “middle of the road” setting, and will work well in many situations.


The Output page

On the Output page, there is a column for every corresponding hardware output.  The faders on the Output page replace the variable output signal level controls found in previous driver versions*; and they allow you to attenuate the volume for the corresponding hardware outputs.  When "mixer" is the selected output source for "1/2 out", the volume slider here has no effect, instead, use the Master Volume control on the Mixer page. 


* Note: The SPDIF out, and all outputs for the Delta 1010, do not have volume, balance, or solo/mute controls on the Output page.

At the bottom of each column is a drop down that allows you to connect each of the Delta hardware outputs to specific audio sources within the Delta board.  Each output source defaults to the corresponding software return (sw rtn, labeled wave out in previous driver versions); for instance, anything assigned to outputs 1/2 in your software will bypass the monitor mixer and go directly out of hardware outputs 1 and 2, and so on.  As mentioned above, the output of the monitor mixer may be assigned to the OUT1/OUT2 analog outputs and/or the S/PDIF Out digital output.  This is done by selecting "mixer" as the output source:


Note: "Mixer" is not an option for the Delta Audiophile 192 because the output of the monitor mixer is always feeding the "Monitor" outputs.


Direct Monitoring

With "mixer" selected as the output source for outputs 1/2, you can now use the volume sliders on the Mixer page to control the levels of the various hardware inputs and software outputs going to your speakers.  Turning up the levels for the inputs allows you to directly monitor your input source while recording, with virtually no latency.


Note: you may need to disable software monitoring to prevent doubling your monitored signal.

By default, all mixer inputs are setup as stereo pairs.  To be able to monitor the inputs as individual mono channels, click "link" to obtain separate volume control over each channel, and center the pan L and pan R knobs to ensure your signal is monitored through both speakers (pictured above).  You can adjust the pan knobs by clicking and moving left/right with the mouse, or click once to select a knob, and use the spacebar to center it.


The Hardware page

You must select external - spdif if you will be recording or monitoring a S/PDIF stream, or external - word clock (Delta 1010 only) if you wish to synchronize your digital audio with a source device that is Word Clock capable.  Once a master clock source has been selected, its synchronization status is continually monitored and displayed above the master clock radio buttons.  If the internal crystal is selected, the status display will always say "locked." 



On the other hand, if external - spdif or external - word clock is selected as the master clock source, the control panel will display "locked" only when a valid S/PDIF or Word Clock signal is detected.  It will display "unlocked!" when there is no signal at the selected input, or when the signal is corrupt or invalid for any reason.




ASIO/WDM buffer size: This section (pictured above) specifies the amount of system memory dedicated to digital audio buffering.  Setting a buffer size that is too small may result in clicks or pops in the audio stream as some data may be lost.  Larger buffers cause slightly more latency but prevent the pops and clicks that might occur with smaller buffer sizes - the default settings are recommended but you may desire to tweak these default settings to suit your tastes.  This buffer size must be set in the Delta Control Panel before you launch your music software.  When using ASIO with your Delta card, set the buffer size in the control panel, then exit the control panel.  After doing so, launch your music software.