Perhaps I should expand on my brief post. I want a vintage Electric Mistress but I don't want the hassle of an old pedal. The Mooer pedal was $88, the Donner a Mooer clone was $24. I got the pedal fired it up and apart from a very slight volume drop I'm pretty pleased with the results.
How are you powering the RV-3, is it daisy chained to other pedals power or isolated? If it's daisy chained try a battery for power see if the noise goes away.
Xmas came early, a maple top charcoal burst PRS 408.
All I can say is it's a very well built guitar, no flaws, no stop tail lowering, no trem setup required, no sticky nitro.