The next step, as it would be for any customer, was an email exchange with Scott to determine where/how I would get the most benefit from his GC1. After describing my setup and its connections, "my recommendation is that I send you two GC1 and a selection of Ground Control cables. Here are some ideas I suggest you try out. All of these aim at signal ground (the internal reference ground of a device) rather than mains earth. I think you live in a rural place so mains earth ought to be quiet already. It would be good to connect a GC1 to your iMac by removing your DVD drive and freeing up a USB port. Connect the Ground Control cable as close to the audio USB connection as possible. Give that a listen with and without the GC1. When you do comparisons, disconnect the GC cable from the component not Ground Control itself. Do not leave the GC cable dangling off the component.

This video from PursuitPerfectSystem shows the new GC-R Reference Ground Control to the inside of the right speaker. The other components on the top shelf were CAD's own DAC and server. 3 x GC-1 on the bottom shelf.

"Once you have done that, use a second GC cable on the same GC1 to also connect to your Soundaware D300Ref USB bridge. I recommend using a free S/PDIF connector. Give that a listen with and without the Soundaware D300Ref connected to the GC1. Now disconnect the GC1 from your Mac and give it a listen with and without the GC1 attached to just your Soundaware D300Ref. Once you decide on the setup you prefer, stick with that and move on to the second GC1. I recommend the exact same scenario but on your Denafrips Terminator DAC and preamplifier. Use the coax or BNC connector on your Denafrips and an unused RCA/XLR on your preamp. The only other thing to mention is that attaching a Ground Control is not an instant on/off switch. It takes time for the high-frequency noise to migrate through the cable, into the GC and for the high-frequency energy/noise to convert into heat and reduce. The best demonstration I have found is to have the GC1 attached for ~10 minutes and then listen to ~60 seconds of a track twice. Then disconnect the GC1 and immediately listen to the same ~60 seconds without the GC1. Please try to include music that has some real rhythm and pace."

At HighEnd Munich 2019, CAD co-exhibitors Bibacord cables had made these custom XLR interconnects with integral ground leads which obviously must be made to precise lengths to accommodate specific installation requirements.

With this road map, Scott knew how to terminate his ground cables and I how to use them. By then I'd tried and reviewed the Consummate Ground Cable by Canada's Gutwire. This also connected to a free RCA plug both analog or digital (S/PDIF on a DAC, RCA analog i/o on a DAC or preamplifier) but on the other end to the AC mains. Despite our presumably clean safety earth and very much unlike for Glen Wagenknecht who'd successfully taken three different such Gutwire cable models through their paces already, their disparate take on the ground-noise topic hadn't worked for me. I was thus curious and hopeful over what Scott's different approach might net me instead.