Comparator fundamentals:

A comparator is an electrical switching system that facilitates the audible and visual comparison of multiple pieces of Hi-Fi and A/V equipment instantly. Refer to the block diagram below for a simplified explanation of a Stereo speaker comparator.

 

Why use a comparator?

The biggest advantage in using a comparator system is the ability to instantly compare many different products. Once a comparator is installed there is no requirement for your staff to physically disconnect and reconnect equipment, wasting your customers and their own valuable time. This allows for either a more relaxing and organised consultation with that one important customer, or many organised consultations with the Saturday morning punters. They will not need to wait as long for your staffs attention.

 

Types of comparators.

There are commonly two broad groups comparators can be placed into, Electro Mechanical and Electronically Controlled.

Electro mechanical comparators are un powered devices that use interlocking mechanical switches to select the product they are comparing. These switches most of the time are not designed for use in an audio signal path, and hence degrade the signal being passed through them. They also require all signal cabling to be run to the rear of the control surface. This can degrade the signal qaulity further, be impractical and also un-economical in reference to the amount of cable used.

This type are not often used in a home theatre set-up, and are fortunately now only being produced by the Home Hobbyist Manufacturer.

 

Electronically controlled comparators usually have their own power source, are controlled via Micro-processors and use relays to switch the signal path. This type of comparator is generally considered to be the more user friendly, and better sounding of the two.

The most important advantage of an electronically controlled comparator is the ability to use high quality relays in the signal path. However not all comparator manufacturers do this as it is also the easiest way to reduce the cost of a comparator system. A typical Home Theatre Comparator system would have many hundreds of relays in it.

Another advantage is the ability to control these relays remotely, this means the signal cabling stays nearer the equipment being switched. This improves signal quality and reduces the amount of cabling in a system. However once again not all comparator manufacturers pay enough attention to this.

 

Reliability

Reliability is the single most important factor in using a comparator successfully. Therefore the comparator system you choose should be manufactured to professional standard and have a very low failure rate, our own is almost unmeasureable.

Knowledge of the equipment being switched is also a factor in system reliability, we often receive a call claiming "our comparator doesn't work" yet after further investigation we find that perhaps the DVD player being used is not set to output a Digital signal.

Installation is a key factor in the reliability of a comparator system. The most common cause of comparator inoperability is either a faulty or incorrect connection in either the comparator system bus or the connections between the system and the equipment being switched. These problems are usually caused by the lack of proper use of cable retention systems or a poor termination in the actual connectors.