The size and type of power supply is also vitally important. The power supply links your amplifier to the AC from the wall plug, so it is a limiting factor of how much power your amp can deliver to your speakers. The weight of the receiver says a lot about the quality of the power supply because it is by far the heaviest component; quality components tend to weigh more than their cheaper counterparts.

If you can afford it, buy a toroidal power supply. This type of construction provides higher efficiency, greater power delivery, and cooler operation. It also provides much more juice than a standard rectangular “EI core” supply. You can recognize a toroidal power supply by its doughnut-shaped core. EI core supplies are square.

Check that your prospective purchase has a glass-epoxy main circuit board. You can tell a glass-epoxy board by its green color. Brown boards are made of pressed paper and are very susceptible to solder joint failure due to expansion and contraction as the board heats and cools. Glass-epoxy boards are much more durable and withstand extreme heat without deforming. A receiver with a glass-epoxy board will last longer; this is generally a hallmark of quality construction found on higher-end receivers.

Another indication of a quality rig is a five-way binding post for connecting speaker wires. This is a large knurled knob that allows you to connect spade lugs, banana connectors, and even bare wires. This is the best kind of terminal to have because it is very versatile; it’s often present on high-quality speakers. Spring tab terminals are the worst because they offer a tiny connection surface area and no alternative to the very small pin-connectors only they support. Worse still, it takes very little movement to knock pin connectors out of the terminal because the small springs that hold them in place weaken over time. Avoid receivers with spring tab terminals; they often have poorly conceived overall designs.

One of the lesser-known evils in home theater amplifiers is dynamic compression, i.e., when your equipment electronically limits the maximum output of the amplifier. You’ll often find this in the convenient and inexpensive home-theater-in-a-box (HTIB) systems. Since the manufacturer sells you a receiver and speakers in a single package, they know precisely the limitations of the system, which allows them to cap the volume at a set point. While this prevents your speakers from clipping, preserving their health and longevity, this seriously limits the capability of a system to play at a realistic volume for many rooms. This is the biggest drawback of the HTIB system. Always test a prospective purchase and listen for punchiness in the bass and clarity in the dialogue during a loud scene. Weak amps will show their true colors here, and you will find it hard to understand what is going on in busy, loud sequences.

A powerful amplifier will grab your speakers and tell them what to do. It is always better to have too much power than too little. Speakers often have power ratings and general recommendations for amplifier strength, though they usually focus more on the minimum end of the scale. If your amplifier is much more powerful than the recommended rating on your speaker, don’t worry; it will provide your speakers with a nice clean signal at all times. Obviously, there are limits, but you will wreck 100 speakers with too little power before you break one with too much.

Finally, you may not have to use an A/V receiver for audio and video switching. Modern televisions, especially HDTV models, have abundant audio and video inputs that allow you to switch between multiple sources using the television itself.

You can still send the audio signal to a home A/V receiver via the audio output jacks. Many TVs have two sets of audio out jacks: one fixed-volume and one variable. The fixed-volume jacks work for using an amplifier or receiver and using the volume control on those instead. This is a great way to use an older receiver whose only limitation is a lack of video inputs. The receiver controls the volume of the sources. Look for a menu function that disables the TV’s speakers.

The variable outputs work best when you have an amplifier with no volume control; the TV’s volume control will control the overall volume of the system. You can also use the variable output with an A/V receiver, but having two volume controls is confusing and will likely degrade your signal. Your A/V receiver most likely has a better-quality volume control anyway, so it’s better to use it with the variable output on the TV.

Please bear in mind that using the TV as a switching device can quickly lead to a confusing and difficult-to-operate system. Most televisions don’t have digital audio inputs, so if you want the benefits of digital audio, you have to send video signals to the TV and audio signals to the A/V receiver. Once the two signals go their separate ways, make two input changes when you change sources: one video input selection on the TV and another on the receiver. Using an A/V receiver that switches both at once will be more convenient for you, but, more importantly, for your family and friends.

One hallmark of a great system is when someone besides the owner can operate the system easily. A properly set up A/V receiver will help you achieve that goal.