The reason you have the issue is that you own a poorly designed overpriced idiotic piece of foolery. If you use a usual intern connect it apparently blows the output. Such a stupid arrangement is out of my experience. Apparently you need a transformer between the units.
Here is your user manual. Look at page 3.
To achieve an ideal sonic performance, the XLR outputs of the Conductor 3XR are direct coupling. ie. It has no coupling capacitors or transformers in the audio signal path. However, direct coupling outputs are NOT compatible with off-the-shelf XLR to RCA adaptors like the ones showing below. Never use these type of adaptors. Using such adaptors to connect the C3XR to any single-ended amplifier with RCA inputs will damage the internal opamps of the C3XR. Doing so will void the warranty. Therefore, to safely connect the Conductor 3XR to any single-ended amplifiers, please use the RCA output of the Conductor. The only adaptor that is permissible is the transformer type of adapters as shown below. (Neutrik NA2F-D0B-TX XLR to RCA Transformer Balancing Adapter)
The epitome of overpriced junk.