Устройство гитарных процессоров

Stompboxes.

Stompboxes, or effects pedals, are effects units designed to sit on the floor or a pedalboard and be turned on and off with the user's feet. They typically house a single effect (though combination pedals, like the Ibanez "Session Man"--which provides chorus and distortion-- are available). The simplest stompbox pedals have a single footswitch; one to three potentiometers for controlling the effect, gain or tone; and a single LEDdisplay to indicate whether the effect is on or not. The most complex stompbox pedals have multiple footswitches, large numbers of knobs, additional switches, and an alphanumeric display screen that indicates the status of the effect with short acronyms (e.g. DIST for "distortion").

An "effects chain" or "signal chain" may be formed by connecting two or more stompboxes. Effect chains are typically created between the guitar and the amp or between the preamplifier ("preamp") and the power amp. When a pedal is off or inactive, the electric audio signal coming into the pedal is diverted onto a "bypass", resulting in a "dry" signal which continues on to other effects down the chain. In this way, the effects within a chain can be combined in a variety of ways without having to reconnect boxes during a performance. A "controller" or "effects management system" allows for multiple effect chains to be created, so that one or several chains can be engaged or disengaged by tapping a single switch. The switches are usually organized in a row or a simple grid.

To preserve the clarity of the tone, it is most common to put compression, wah and overdrive pedals at the start of the chain; modulation (chorus, flanger, phase shifter) in the middle; and time-based units (delay/echo, reverb) at the end. When using many effects, unwanted noise and hum can be introduced into the sound. Some performers use a noise gate pedal at the end of a chain to reduce unwanted noise and hum introduced by overdrive units or vintage gear. Guitar pedalboard.

A guitar pedalboard is a flat board or panel which serves as a container, patch bay and power supply for effects pedals for the electric guitar. Some pedalboards contain their own transformer and power cables, in order to power a number of different pedals. Pedalboards assist the player in managing multiple pedals. The entire pedalboard can be packed up and transported to the next location without the need for disassembly.

Pedalboards often have a cover which protects the effects pedals during transportation. There are many varieties of pedalboard cases, including homemade DIY pedalboard cases, store-bought pedalboard cases, and, for professional musicians, custom-made pedalboard cases. Hard shell pedalboard-cases have foam padding, reinforced corners, and locking latches which protect the pedals during transport; during onstage performance, with the lid removed, the bottom of the case is a pedalboard. Most pedalboards have a flat surface where pedals and their power supplies are attached using Velcro or other techniques, and they often have a removable lid or padding to protect the pedals when they are not being used. Some pedalboards have handles or wheels to facilitate transportation.

Pedal power supply. Most effects pedals are powered by varying levels of DC voltage, depending on the manufacturer. Possible voltages include 9V, 12V, 15V, 18V, 24V, and 40V, though 9V is most common. Some effects pedals accept a range of voltages, producing different effects. Guitar players can experiment with varying voltages to generate different sounds.

DC power can be generated by batteries, an AC/DC power supply, or a rechargeable battery. Each has its own advantages and disadvantages. Using individual batteries is fine for occasional players, because they don't have to worry about the cost of replacement batteries or changes in sound as batteries get tired. Battery life varies depending on the pedal's power draw. Professional players normally replace all batteries with new ones before a show.

Using a DC power supply is a good alternative, even though the initial cost is higher. However, one has to pay attention to ground loopsand power line hum. Noise gates can help to reduce the noise by suppressing the signal below a certain volume threshold, but this only controls unwanted noise without actually removing it from the signal.

The third approach is to use a powerful rechargeable battery to drive all the pedals, and a battery charger to recharge the battery. This eliminates ground loops because the pedals are grounded at a single point: the amplifier. There are batteries on the market that can power over 20 effects pedals for eight hours on a single charge. The effects pedals are connected to the rechargeable battery via isolated DC-DC converters, which produce the required voltages.

Using a rechargeable effects pedal battery or AC/DC power supply in conjunction with a “pedalboard suitcase” reduces setup time prior to a show.

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