AC Conditioners?

I use a Monster HTS2000 power conditioner with good results. I live in LA and have a very dirty power supply. It may restrict the dynamics somewhat but it is hard to tell because without it the background noise level is much higher, and there is as well a very noticable drop in detail. My system sounds better and more musical with the Monster and it was only $125.00 mail order. I also run my amp through one of the special "amp" outputs (that claim to not restrict power/dynamics) with better results than straight into the wall. I guess that it all boils down to which is the worse of two evils in your particular situation. My gear is not expensive but is also not midfi.

I live in Chicago and have the lesser of the evils syndrome as well. I use a newcastle conditioner and the noise it reduces is nicer to listen to than the garbage on the line. My system is about 25K retail, so I do not think I am at a Mid-FI level. I mainly use the conditioner in case of spikes and browns. In the spring and the fall I do plug directly in the wall between midnight and 4am to realize what my system can do -- and it does some things better on the conditioner and others better on the wall outlet. Trade-offs galore...

There's a Cinepro 20 Line Balancer for sale right now at less than 50% of retail, on Audiogon. I have one, and it's far better than the API Power Wedge I now have in basement storage. If you can afford $850 (a guess from memory), you can't do better. An idiotically lukewarm Stereophile review has kept this conditioner from being as popular as it should be. It splits 120V into 60V+ and 60V-, a brilliantly simple idea, which leads to the lowest noise floor ever.

Braiding Power Cords? I have done so and found some improvement. What IS the brading of the line doing???

I have used the Noisetrapper, Power Wedge I, improved power Wedge 1, the Power Wedge 116, and they all hummed. The newer ones aren't supposed to. They decreased the noise in grundge out of the AC, but they increased audible noise from their transformers. The Chang 6400 was next. Better, quieter, but tended to thin the body of the music. It sounded better in my friends system then in mine. I've settled on a Monster 2500(2000 in a metal chassis) and it does a lot to cleaning a midbass hump I was chasing in the system. The highs were also improved with the bass tighter. Dedicated lines are a must. I use two with 12ga romex underground in conduit with 20 amp breakers. Listen before buying.