Power conditioner or not?

I am confused! Per Naim's recommendations, no power conditioner needed. I have a Naim system, what do you think?

Bryston manuals say the same. That is the way it should be in a good product. However, with switched mode power supplies common these days and therefore dirty power not uncommon - not all components live up to this promise...perhaps power from the utility is sometimes completely out of tolerance too. Whatever the cause, power conditioning sometimes helps - in a perfect well world it probably shouldn't be necessary at all...try it and see if you can hear a difference - however make sure it can handle the instantaneous current requirements for your power amp (as generally it is not recommended to restrict the supply to your high powered gear - some stuff is designed to work with power amps).

Musicnoise,

The scary fact is that some audio equipment does indeed benefit. I blame it on "switched mode power supplies" in many common household items from battery chargers to computers - these can be noisy. In the past everything used to be powered with large isolation transformers but not today. I have one component that benefits and it is digital - I don't know if it was jitter or what was wrong but a power conditioner helped. I tested two conditioners and both had the same effect on only one component. Naturally I will change this component next as I suspect less than adequate power supply isolation to the electronics somewhere.

I think you are right in principle as the best designs with overbuilt good power supplies should not need power conditioning in most normal situations.