How do I ground a system with mono block


I just recently switched to mono amps and now I have a ground loop. With my single chassis amp it was simple . . .it was the only piece of equipment grounded. Now if I lift the ground on one of the monos I break the loop and everything is fine (my pre amps power supply has a ground/float switch and I have it floating)but what I wonder about is with the directionaly shielded cables what happens to all the RF noise that the shielding picks up if the amp is not grounded? Sorry if the question is stupid but I just gotta know :) Gene
geeeno

Showing 1 response by scottfrankland

The basic problem is that the interconnects ground the preamp to the power amp. If the individual chassis are then grounded via their power cords you have a ground loop. Even if you use the same AC outlet for all power cords you may still create a loop. Since the preamp is the low-level signal amplifier, grounding the preamp and floating everything else gives the lowest hum and buzz in most systems. The preamp is also the most rf sensitive component. So, since the preamp is grounded to earth, and the amps are grounded to it via the interconnects, rf tends to move toward the preamp chassis and bleed-off to earth. Besides hum, buzz is created by down-conversion of AC line harmonics via the parasitic capacitance between your power transformer windings. This is something that the new PS Audio power conditioners address. Ditto for the Jensen input transformers.