KnowledgeBase | K2500R | Audio Output


Working with the K2500 Digital Outs (KDFX Installed)

Question:

I have the KDFX option installed.  How can I enable the K2's digital outputs?

Answer:

For a K2500 with KDFX installed but NO sampling option installed:

The provided Coax & Optical outs are "always-on", fed by the internal A-bus. This is a fixed unalterable routing. Only audio routed to the A outs (Studio Editor/ OUTPUT page) will appear at the digital connectors. The signal is output at a fixed rate of 48kHz and must serve as clock master (ie it cannot slave). The output bit depth is 16 or 20 bits, software selectable via the “DigOut” parameter at the bottom right corner of the EffectsMode/ CTRL page. The eight channel KDS output (for connecting to the DMTi) is also active and provides a copy of the signals routed to the eight separate outputs.

For a K2500 with KDFX and the sampling option installed:

With both KDFX and the sampling option installed there are several options for generating digital ouput.

You will see a new parameter added to the sample mode, Input:Digital page called "Out".

If it is set to "Dir" (Direct), things will behave as described above (K2500 with KDFX installed but NO sampling option installed).

If you switch the Out parameter to "A/D", then the signal at the analog MIX outs is resampled through the sampling option circuitry and passed to the digital outs. This method provides a 16-bit stereo digital output, via both coaxial and optical connectors. As this digital stream is actually the output of the sampler's analog-to-digital converter, it can also be used to convert external analog signals into AES/EBU or SPDIF format. This can be at a selected rate, either 48, 44.1, 32 or 29.6kHz, or can be slaved to an external clock.

Here's a step by step explanation of how to make the sampling option digital output work:

  1. Go to the Sample Mode page. (In Program, Setup, Quick Access, or Master mode, press the Sample soft button.)
  2. Set the value of the Input parameter to Digital.
  3. Set the value of the Format parameter as needed. SPDIF is the most common setting. You may want to use AES/EBU in professional environments.
  4. Set the Out parameter to "A/D".
  5. Set the value of Input to Analog to access the Source and Rate parameters.
  6. Set the Src parameter to Int for the K2's own analog mix output, or if you want to convert an external analog source to digital, set it to Ext.
  7. Set the Rate parameter as needed for cases where the K2 is the master. If you need to slave to an external clock, connect the master signal to the digital input, switch Input to Digital, and set the value of the Cable parameter to coaxial or optical, based on the digital input. The Input parameter controls whether the K2 is the master (Input=Analog) or slave (Input=Digital).

At this point if you generate audio on the K2 you should see its sample mode meters light up active, indicating the digital output is sending.

Assuming your receiving device is setup correctly (meaning as either master or slave, depending on your desired configuration) you now should have audio.

NOTE: when using the Out:A/D digital outs, it is important to realize that the digital signal is derived from whatever you have routed to your analog MIX outs. So if you are currently setup where you have multiple analog outs in use, routing things to different places, this will in turn affect what you hear (or don't hear) from the digital outs as well. So if this applies to you, the simplest thing to do is temporarily disconnect any analog cables you have physically attached to any of your individual (A-D) outs. You can leave any cabling attached to the Mix outs, those will not affect things.


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