I need advice for power cords


In my system there are 4 components that power cords are interchangeable.  They are PrimaLuna EVO 100 Tube Preamplifier, PrimaLuna EVO 100 Tube DAC, Manley Chinook phonostage and Dayton Audio sa1000 subwoofer amplifier.   Should they all be upgraded, if not all which one to change to give me the most improvements.  I can't go crazy on cost, 1k to spend.   I've followed along with many threads on this subject. Always looking to make improvements to sound quality.   Many of you have much more experience with cables than I do so what do you recommend and I can do the research.  On a side note my McIntosh MC75's are vintage so old thin manufacturer cables and probably shouldn't change them. 

Thanks 
Mike 
zardozmike
I recently picked up a pair of Synthetic Research master coupler power cables from AudiogoN.  I will be using them on my preamplifier and phonostage, my analog setup is the most used.  Will update when I get them and have had a chance to listen with them installed. 
Have to be honest with you I wasn't sure the power cables were going make more than a subtle difference.  I have been listening all day with the new cables and am astounded at the improvement.  It really shows up in quieter jazz albums, I can hear so much more I guess this is what lowering the noise floor sounds like. I've gone the tuning fuse route and that made a huge improvement.  I guess until I've tried it's not snake oil. 
The house wiring has nothing to do with it.  It's all about the cable you use from your power conditioner to your equipment.  Simple as that.