MC-pre stage minimum distance from poweramp

To avoid hum/noise pick up which is considered a safe distance from the power amp ? The distance of an IC cable of 3 feet would possibly enough ?
Twelve inches is probably enough in most circumstances. Surely a standard interconnect length would be more than enough. Are you having a problem with hum? If so and assuming you have a light to illuminate your turntable, you might want to unplug it to see if that is the source. Is your turntable grounded to the preamp? Is your turntable far enough away from the other components? Beyond the above, you should start lifting the grounds one piece at a time. Certain cartridge and table combinations are subject to hum. What equipment do you have?

I have a PT Export+ Sme 309+ Denon DL 103 + Coph nia MC pre stage (60dB gain) + Goldmund pre and power amp. Cables are unshielded Silver cables from Homegrown audio.

Everything was settled and I only had a minor background hum with volume at 11.00, but it was overlayed by the music.
Then I changed the speakers and needing the new one more gain to play loud, it seems that the hum is more evident.
Or more probably the more transparent speakers let the hum more evident.
Tks for your advises