I really love the sound of this mod. However there are problems on playback if left alone.
This applies to ADA8000 units manufactured after late 2009 (units with a date code label reading "0912" or later). In late 2009, the ADA8000 implemented new D/A converters from CIRRUS which offer improved quality compared to the previous D/A converter chipset.
However, the new D/A converter chipset goes into mute after receiving 8192 consecutive samples of digital zero (absolute silence, or "digital black"). The next non-zero sample reactivates the D/A chipset which creates a short waiting period as the D/A chip "wakes up" and the audio output level returns to normal.
Under normal operating conditions this auto-mute never happens. However when used with digital mixing consoles or digital audio workstations (DAWs) with all faders down or in stop mode, this could cause this "mute" or "sleep" behavior.
The offending chip is a CIRRUS LOGIC CS4270-CZZ http://www.cirrus.com/en/pubs/proDat.../CS4270_F1.pdf
There are 4 of these chips on the board. I am not sure what is a suitable replacement. You can, as a workaround send an inaudible signal to keep the unit responding quickly all the time.