I am a happy user of the ADI2 Pro FS R BE for the past few months.

My question is whether SRC Gain should be left at 0dB or -3dB in order for the SRC to handle inter-sample peaks of up to +3 dBFS?

This is for normal payback purposes in AD-DA mode and not for recording via USB.

Regards
Rajesh

From the manual I see the following:

In Section 8.6:
The ADI-2 Pro includes an asynchronous stereo sample rate converter (SRC). A SRC allows a conversion of the sample rate in real-time. The converter used in the ADI-2 Pro operates practically without loss of signal quality, so no audible artefacts or noise is added. It also handles inter-sample peaks (ISP) up to +3 dBFS without added distortion. In fact, the SRC works so well that we could recommend to just leave it on at all times, thus eliminating all clock problems right from the start. Which is the case for the SPDIF input in Auto mode.

In Section 14.1.1:
SRC Gain dig.
Available settings: 0 dB, -3 dB. Default: 0 dB. The SRC uses digital headroom to handle inter-sample peaks up to +3 dBFS without distortion. With the -3 dB setting, an SRC signal with up to +3 dBFS can be recorded via USB without distortion, or passed on at the AES/SPDIF output in Dig Thru mode. A normal SRC input signal with 0 dBFS then has a level of -3 dBFS for these two paths.