Now listen what part of noise is Sure3116/PSU, shortcircuit inputs, so just Sure poweramplifier connected to PSU and speakers, no preamp, closed inputs. You might have cinch/rca caps you use on preamp open inputs? Like on phono2 input? If not you can put two little wires through direct inputs next to rca.
There is a little powerup crack almost inaudible with inefficient speakers, not just Sure3116 but also audiobah/ac1308, hard to imagine that being a problem but add 20dB ???... also PSU can inject noise ofcourse, higher voltage more noise, bad linear or smps more noise than better ones.