well, after trying to interpret all of the solutions for the FX loop (I'm a novice when it comes to this stuff - just finance my son's music interests!
) I finally figured out the solution; thanks again to Nik's wonderful help and the postings of others on this forum.
I purchased the following Y cable: Hosa YPP-117 - and the results are fantastic!
While the Ceriatone DC-30 accepts pedals well the difference in using the FX loop is significant - my son runs a fairly extensive pedal board with delays, phasers, some fuzz, etc...and the "line noise" is whisper quiet and clear.
This simple solution makes the DC-30 even better than it's been already (which is great!)