To Float or not to Float...

Jim - My only front end source is a Resolution Audio Opus 21 cd player which uses a three prong power cord which presumably grounds it.  The cd player and preamp are both plugged into a power strip which I was told is recommended for use with Naim equipment and also utilizes a three prong cord and receptacles.  I initially thought the buzzing was caused by the interconnects between the pre and power amp, however swapping them out for different interconnects did not alleviate the problem.  I was have issues with the IEC female connector on the power cord making consistent contact, and, as I reported, changing that has seemingly solved the problem.  As to why the buzzing stopped when I switched to "ground" position, the technical answer is above my pay grade and I will let those of you with greater expertise ponder that...

I have so many things plugged into my system I'm amazed at how utterly quiet it is. There are bespoke DC buzz killing power supplies on the DAC and phono preamp, a PS Audio Humbuster III for the tube and SS amps, no ground pin was provided for the main preamp (Kavent S-33 dual mono masterpiece) weirdly, but doesn't seem to matter, and I did have to lift the ground via a small switch on a REL Q150e due to a small hum issue. Otherwise, although my SEP main power amp is working fairly hard in its Class A massive 12 watts (or something) per side, it is also dead quiet…blacker blacks, redder reds, more opaque opaqueness, you know what I mean.

Never lift grounds on power amplifiers. you don't want that to go live with the currents that can easily kill you. If however your house is correctly earthed the breaker should go before there is any damage done to the equipment or more importantly you. Unless as said above manufacturer has a ground lift capacity on the board " no "always leave grund in place. if you have a ground loop "buzzing" noise lift the earth on the pre amp as interconnects can more than likely handle that current going back to earth. But as said check connections are tight and that balanced connectors are wired the right way in phase etc. Pull the power amplifier as far away from the sensitive circuits in the preamplifier as some are oversensitive and away from central heating circuits , strip lighting. There are many noise sources that cause these issues. Often here is no need to jump to lifting mains earth on audio gear.

jea48 is the go to person when it comes to electrical wiring and safety.  Trust his advice. 

 I also have a pair of DeHavilland mono block amps with the same ground/float switches, and in the manual it states that leaving the switch in the "float" position may result in a "cleaner sound".  At any rate, a fully functioning grounded power cord has done the trick...

If the grounding scheme of the audio equipment is properly designed and executed there will be no need for a ground lift switch. The chassis will simply be properly grounded through the AC power cord's third prong and doing so will in no way affect the sound.

@jea48 has been correct in his assertions.