When I unpacked the RS520 sample reviewed by RvB, I heard something metallic rattling around inside the amplifier. The nut holding one of the speaker binding posts to the printed circuit board on the back panel had come undone. I found the binding post inside the shipping box, and when I removed the top cover, I found the nut inside the amplifier. I reattached the binding post, but when I removed the top panel, the two ribbon cables that connect it to the main circuit board detached. As hard as I tried, I couldn’t manage to reattach these cables. I requested a new sample of the RS520, which was promptly supplied. I measured serial number EBK302CB000118.
I performed the measurements using my Audio Precision SYS2722 system. As the HiFi Rose is a class-D design and class-D amplifiers emit relatively high levels of ultrasonic noise that would drive the analyzer’s input into slew-rate limiting, all the measurements other than frequency
