Reference

Dressing
Tonearm leads, digital cables, interconnects, speaker cables, and power cords should be kept as far away from one another as possible. In addition, all cables should be kept as far away from electronics as possible. There will be obvious limitations to these rules, so when cables must cross, they should form an X where they meet---if possible, raise one of them up off the other.

Many audiophiles feel that their systems sound better when all the cables are raised off the floor---especially if the floor is carpeted. While a number of commercial products are available to keep cables off the floor, you can experiment by putting upside-down paper cups or small cardboard boxes under your cables and seeing if you hear a difference. Since the cost of trying this is virtually nil and there's no risk to your equipment, it's an ideal tweak to try. [When I recently visited Audio Power Industries' Les Edelberg, I was intrigued to see him using old power tubes for this purpose. It seemed very appropriate.---Ed.]

Power supplies
Many pieces of audio equipment, such as preamplifiers and digital processors, have separate power supplies. Keep the power supplies as far away as possible from your other equipment. While stacked equipment may look nice or save space, it often has a negative impact on the performance of your audio system. Tall racks with multiple shelves often provide the necessary spacing to keep components separated enough to minimize various forms of interference and interaction.

Grounding
An audio system's hum can often be minimized or eliminated by disconnecting ground connections on some or all electrical equipment. (This is called "floating" the ground.) But remember: electricity is potentially harmful to both you and your equipment. Always begin by plugging everything in with the supplied power cords. (It's useful to know that some equipment is not grounded, even if it has a three-pronged power plug.)

Once everything is plugged in, listen for hum. If you can't hear hum without having to listen for it, leave everything alone. If you do hear hum, try floating one piece of equipment at a time (starting with the source components) by using a cheater plug without connecting the ground wire. Make sure you have the components interconnected with the signal cables while you do this experimenting. While many audiophiles use this tweak, I strongly advise you to use caution. Ideally, everything should be properly grounded. At minimum, one component in your system should be grounded. [Please note that Stereophile accepts no responsibility either for damage done to readers' components or for injury to its readers caused by incorrect grounding or by messing around with the wall AC supply.---Ed.]

Plug polarity
In addition to grounding, many audiophiles report hearing significant improvements by reversing the polarity of the plugs on various power cords. You can try this by connecting the power cord into a cheater plug; then listen with the cheater in right-side up or upside-down (reversed polarity). (You may have to file down the larger leg of the two-pronged cheater plug to be able to do this.) Once you've determined which sounds best, orient the plug accordingly.

A slightly more expensive alternative is the Elfix AC Polarity Tester, available from Audio Advisor, Inc. By once again using the ubiquitous cheater plug, you can objectively determine the plug orientation that gives the lowest AC voltage between the component's metal chassis and the signal ground (with, this time, the signal cables joining the components disconnected). You can also use an AC voltmeter if you have one.

Once you've determined the desired polarity with either method, eliminate the cheater whenever possible. You should continue to use the proper ground connection with this and every tweak.

Source of electricity
The cleaner your power source, the better your system is likely to sound. If possible, plug your entire system into a separate, dedicated electrical circuit. Since few of us can afford to bring separate electrical lines into our homes for our audio equipment, try using a dedicated circuit from your main electrical supply. If you can't use a dedicated circuit for your audio gear, try to select a circuit that has no dimmers or major power draws (refrigerators, furnaces, air conditioners, etc.). Your female outlets can be upgraded to make firmer (and better) contacts with the plugs from your power cords. These "hospital-grade" outlets, from manufacturers such as Hubbell, are readily available. If you have any doubt whatsoever about your ability to install the upgraded outlets, have a qualified electrician do it.