After hooking the amplifiers up and turning them on I was welcomed by an audible noise coming from both loudspeakers, which persisted although I tried reducing it by using a double shielded interlink and a different mains cable. Despite the noise I went ahead and started listening to a number of my favorite tracks with which I’m intimately familiar. What was immediately obvious is that the Reference 8 adds an artificial edge to the treble, most notable with percussion and female voices; as if a high-frequency oscillation was added.

I decided to take my pre-amplifier, which is a double-triode tube design, out of the loop and use a passive preamplifier instead. This passive preamplifier features two stepped attenuators and an input selector, no more, no less. The changes were subtle, the noise which was clearly audible with the tube preamplifier had been reduced somewhat and the artificial edge in the treble was mostly gone. This led me to conclude that the Reference 8 amplifiers put out a significant amount of RF and hence influenced the components in my setup directly, more specifically the tubes in my preamplifier.

To test this hypothesis I decided to turn on my A/V receiver and see whether it is still able to find radio channels in the AM and FM band. I wasn’t surprised to find that only the strongest FM channels could be received. Turning on the TV and opting to use it with the antenna rather than the wall mounted cable socket yielded similar results. Therefore it is safe to state that the Reference 8 amplifier puts out an unhealthy amount of RF, which puzzles me as NuForce claims they adhere to FCC regulations.