Power conditioner some say yes and some say no.

I worked for Roger Modjeski for several years. He was always of the opinion that if you designed the power supply of a component properly then additional power conditioning would not be needed. In his system he used an inexpensive power strip, mainly just to have the ability to power on/off all his components simultaneously.

@clio09 I've found this to be true too- you really have to regulate!

If regulation isn't an option then a power conditioner can do some good- but it had better actually be a real power conditioner and not a glorified power strip (which describes most of the 'high end audio power conditioners'). If you don't push them too hard the PSAudio power regeneraters are quite decent.


The best conditioner I've seen was made by Elgar for commercial industrial use. It has the ability to regulate line voltage and put out a clean since wave (with guaranteed distortion less than 0.5%) right up to full current, some of which can support 28 amps continuous! These units are older as Elgar got out of the business decades ago and so have to be refurbished with new filter caps for their power supplies and the like. But they do offer improved sonics!


Its the 5th harmonic of the AC line frequency that is arguably the most pesky. This can occur when the line transformers on the telephone poles are pushed past 50% of their total capacity of for that matter any transformer in the chain between the power plant and the wall outlet. The 5th harmonic is hard to filter out because of its low frequency (300Hz) so the smaller 'conditioners' simply can't do it. It can cause power transformers to run warm and make noise, diodes to radiate more 'diode noise' and synchronous motors to perhaps run the wrong way. You can google this topic; Fluke instruments has a number of articles available.


Most of the 'high end audio power conditioners' I've seen are deleterious to the performance of our amps; I tell our customers to stay away from them or only use them for the front end of the system.


Many audiophiles understand that power cords can have a sonic effect (which is caused by the voltage drop across them- they are subject to Ohm's Law like everything else in electricity); consider that a glorified power strip forces you to use one power cord for a variety of stuff which might include two monoblock amps. If the amps are rated to make full power with 120 Volts available, there's good chance this won't happen if the voltage drop on the 'power conditioner' power cord is significant (2-3 volts is not unheard of). If the power cord or the connectors it uses (including the AC outlet) tend to get warm that's a Bad Sign. I've seen this phenomena rob an amplifier of a good 40 watts of output power- under those circumstances its easy to see how this could also be audible :)

The power in my old house, mostly ungrounded outlets, as well as the line coming in are atrocious.  Start the vacuum cleaner and lights dim for a second.  A used PS Audio regenerator made a huge improvement.

With sryeager being an exception, in general here are steps I find helpful.
1. Breaker box should be updated to move your room away from air conditioners, blowers, and other high draw breakers
2.  Add a whole house surge protector
3.  Put your equipment on an isolation transformer https://www.amazon.com/gp/product/B00008YMZO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
4. Use shielded power cables https://www.mouser.com/Wire-Cable/Cable-Assemblies/AC-Power-Cords/_/N-bkrhnZ1yzvvqx?P=1z0t1rp
5.  Stay away from Blue tooth and unplug wall warts.  Both generate high frequency noise which most linear power supplies are not designed to filter 
6.  If your equipment has rca and earth ground connected each component going to earth ground creates a ground loop

If you buy the isolation transformer and find it hums  too much open it up and install rubber vibration absorbing feet from parts express between the transformer and the case to help keep it quiet.  Setting on an inch thick cork pad from Amazon also helps.

We obviously are dealers, so you can take what I say with a grain of salt…but isolation transformer based power conditioners just plain work!  Take out of the equation, the fact that they might improve the sound of your system and let’s just look at the fact that they will absolutely protect your valuable electronics. Here in New York in the summer, we have many many brown outs. These brown outs are milliseconds in length, but can do significant damage to your system because of the massive current that occurs right after the brown out.  One summer, we blew out four transformers from a pair of mono block tube amplifiers from two different manufacturers.  Since installing an Isolation Transformer six years ago, we have had zero issues.  By the way, it also improves bass response, and gives blacker backgrounds.