Introduction
Before I start describing the unit itself and my experience with it, let’s talk about power, AC power. The vast majority of our audio components use AC power and look for that power coming in at a certain frequency, usually 60Hz. Unfortunately, in a less than perfect world, there is often a lot of "dirt" that comes in with our power, making that 60Hz sine wave less than perfect and also causing variations in voltage. This "dirty" power makes your power supplies in your equipment work harder and can also effect the sound and picture quality of what you hear and see.

Power pollution comes from many places before it gets into your home. Inside your home, many of your appliances generate noise, which travels into your power lines and into your equipment. You could do what I did and install dedicated circuits for your audio system, which helps, but you may need to do more. Most of the components in your system generate a lot of noise that is sent back out into the power lines for the next component to pick up.

Traditional power conditioners filter the noise out of the line coming from the wall, but do nothing to prevent noise coming from components plugged into the filter from entering other components.

The HTS3500 Power Reference Center ($399) addresses this issue with multiple filters. The unit contains four banks of outlets, each with its own filter, so that noise generated by a component on one outlet will not enter another. In addition to the filters, the HTS3500 also helps by increasing the power factor. The capacitance in the filters offsets the inductive load found on the AC line, pulling it towards a resistive load, making more current available to the amplifiers and other components.

As for the unit itself, the HTS3500 is pretty full-featured and should suffice for all but the most intricate systems. This well-designed, rack-mountable unit has several status LEDs, an expanded scale voltage meter reminiscent of the meters on Sunfire amplifiers, meter light controls and controls for turning switched outlets on and off. On the business side of the unit, there are 10 AC outlets, two switched, two switched with a delay and six unswitched. There are also filters for three coaxial RF lines, a phone line, a ground post and provisions to turn the switched outlets on remotely via an AC or DC trigger. If that is not enough, the HTS3500 also provides complete surge protection.

Setup
The AC outlets are divided into four blocks of filtration. The first two blocks have filters designed for audio components. Two high current outlets are provided for amplification. These outlets are switched, on a delay timer to prevent the thumps and bumps that can occur when turning systems on and off. The next two outlets are also switched but are do not have a timer and are designed for low-current audio devices such as tape decks, preamps and turntables. The next block has a filter designed for video components, is unswitched and has two outlets. The last block has a filter designed to work best with digital products, is unswitched and has four outlets. While you can hook up any of your gear to any of the outlets, the filters are designed differently. This means that the video outlets have a filter best designed not only to provide clean power going to those outlets, but to prevent noise typically generated by video components from getting back into the HTS3500. As video, audio and digital components all generate different types of noise, different filters are used for optimal results.