Physical separation between BHK preamp and amps

The BHK preamp manual says:
Care should be taken to keep it away from power amplifiers or large potentially hum inducing products.
Presumably, this could include a P10 as well. How far is sufficient?

palerider - this might sound a bit obvious but ‘until there is no hum’ comes to mind. Everyone’s set-up and therefore results will likely be different. Cable type, how good the shielding, location of power cables, cable dressing along with proximity of the power sources of adjacent units will all influence the results. It could be as little as 5cm or as much as 10s of cm - I think cables are most of the problem.

If you use good quality shielded cables, try not to run power cables and signal cables in parallel, better if they can be physically separated by a several centimeters and if they cross, cross at right angles will all help.

I’ve had the pre-amp about 10cm away from the BHK 300 and not noticed any hum but I’m always careful about cable placement and I don’t have to shoe-horn units in to a limited space and therefore don’t have to ‘bundle’ cables behind a cabinet for example.

Thanks. No doubt, and while maybe obvious, it’s the rule. My system is dead quiet. All I needed to worry about I guess.