10. Frequently Asked Questions (FAQ)

Pedals, which the signal passes through before reaching the amp, especially those in bypass mode, can cause some volume and treble clipping. This is why many companies are now equiping their effect pedals with a ''True Bypass'' which means the signal does not pass through the effect when the pedal is inactive. The same effect could also be achieved by always having a booster at the front of the signal chain.

In a loop the negative effects aren't quite as bad because the signal which comes out of the pre-amp is strong enough to compensate. Of course cheap effect pedals can still cause issues here. For those who want to preserve the original sound of their amp, the best solution is a parallel loop path.

A note on cabling: The sequence in which effects are wired together is a result of the previously stated options. It also shouldn't go unmentioned that paying a lot for a guitar cable makes no sense if the individual patch cables, used for connecting effects, are bad quality.

The easiest solution for this problem would be a volume pedal placed before the amp so that the change is done at 0. Even more elegant, because the cables don't need to be removed at all, is the use of an AB box. Both guitars (there are also models for 3) remain wired, you just have to switch over. Various Looper / Line Selectors (such as the BOSS LS 2) also offer this option.

An AB-Box is also needed here. There are special devices that switch one signal between 2 or 3 different outputs. For this you really need professional grade equipment, otherwise it can result in a ground loop/feedback. You can also use the BOSS LS2 for this purpose.

Condensing with a microphone is still the most natural and the most used method in a studio setting. The unique characteristics of the amp and cab come through most clearly this way.

The drawback to this on stage is that you have to reach a certain volume level for the guitar to sound good. Otherwise the microphone will pick up unwanted sounds from the stage and other sources. Because of this the ''Line-In'' method is being used more and more often. The amp is removed from the picture and the guitar signal goes directly from the guitar to the modelling amp (the new models simulate not only amps but different cab / condenser mic combinations) and into the mixer. The advantages here are that the sound levels are always the same, the effects are easier to hear and there is no interference from other signals. In addition the line in sound has gotten so good with current devices (Digitech GNX/Genesis/Line 6 Pod XT) that you can safely do away with the mic entirely. Finally you also won't need to move so much stuff from gig to gig.

This also removes the roar of the amp on stage (Your sound engineer is jumping with joy!) meaning monitoring wins out in this situation because you have to hear yourself play somehow.

Each channel has its own basic sound and are achieved by using different circuits in the amp. You will encounter the following channels most often:

Clean:
Refers, not surprisingly, to a clean, undistorted sound. Too many mids are usually undesirable here, clear highs and clean bass may give an electric guitar somewhat acoustic characteristics. You can get the cleanest sounds with a Strat DI box wired directly into the mixer, but most guitarists prefer a slightly fuller and warmer clean-tone. The best-known amplifiers for good clean sounds are the Fender Twin Reverb (tube) and the Roland Jazz Chorus (transistor).

Crunch:
When the inventors of the Mesa Boogie gave their MK III amp a third channel at the end of the 80's they named it after the sound it produced - ''crunch''. This sound can be described as just having passed from clean to distorted but which hasn't quite reached the ''sustain'' area, rather it..... ''crunches''. This sounds is great for riffs and rock rhythms but also for bluesy solos. The classic version of this sound is created by turning up an amp without a master volume, in modern amps there is usually a specific channel, but you can also produce crunch sound in the lead channel with careful control of the gain.

Recently smaller amps like the Vox AC 30 and the Fender Deluxe have become legendary for their harmonic crunch-sound. But older Marshalls (without master volume) can still deliver it, just much louder.

Lead:
At the beginning of rock music the lead guitarist was the one who could play chords and was from time to time allowed to play melodies (Lennon usually played rhythm guitar and Harrison lead guitar for the Beatles). But with the entrance of Clapton, Hendrix, Beck, Page and others the responsibilities of a lead guitarist changed, now spectacular solos were expected in a new sustain rich and distorted sound. The term ''lead'' now refers to this sound, which is used for riffs and dirty rhythms.

The legendary and classic lead sound can delivered by Marshalls and Boogies. But the choice of incredible amps is unbelievably large these days.

A pre-amp is, after the input (jack), the first stage that the guitar signal passes through. This is technically a bit simplified; actually there are several stages: For amps without a master (volume), where the distortion is only produced in the final stage, two ''gain stages'' are enough, for a classic ''crunch'' three are needed, and modern high gain amps have 5.

Initially the signal should only be amplified to a level at which the power amplifier can produce the desired volume.

But rock guitarists in the late 60's and 70's wanted more and more distortion in their sound and this required extreme volumes. So resourceful minds like Randy Smith, who became very successful with his Mesa Boogie Amps (which had multiple pre-amp stages wired one after the other - the so called ''cascade'' set up) came up with the idea to create distortion in the pre-amp stage, which produced the required sound even at lower volumes. To achieve this an amp will then have a pre-amp - which controls the gain of the pre-amp stages (creating the distortion) and a master control, with which the power amp volume is controlled. Still, many guitarists prefer the final stage distortion of a fully maxed out tube amp without master control to the ''fuzzier'' and more compressed pre-amp distortion. In fact, a moderately distorted pre-amp is often combined with a fully saturated (maxed out) power amp, but the musical style also plays a big role here.

An effects loop can be described as an output (pre-amp out, send) and in input (main in, return) through which an effect, which shouldn't be warped by pre-amp distortion, can be looped in. Chorus and flanger are good examples in addition to ''time'' effects like delay/echo and reverb/hall. It's important that the effects are not overdriven by the amplified signal, so with some better amps it is possible to mitigate the signal for the effect loop (e.g. -10 dB). Another variant is a parallel effects loop: In contrast to a serial loop, where the complete signal passes through the effects chain, only a limited part is sent through and mixed with the original signal of the amp. This is especially interesting for studio / rack effects, where the direct signal can be hidden. So the guitar signal goes through 100% of the effect and is then added to the original signal.

Transistor amplifiers came out at the end of the 60's, but despite many technical advantages (no tube change, higher reliability, being more easily serviceable, lower weight, and much lower price) they have never quite been able to compete against vacuum tube amps. The first reason for this has to do with their acoustic characteristics (which is naturally the most important to musicians). In comparison to typical tube amps the transistor amps sound ''colder'' and too clean (As far as clean sounds are concerned, individual models already have their own reputation's, such as the Roland Jazz Chorus, with its built-in chorus effect, which is largely responsible for the popularity of this effect). Another reason is that the distortion from a standard transistor amp sounds, in comparison to tube amps, rather harsh.

Today this view is no longer so easily maintained because, even before there were modeling amps, transistor amps were built which were acoustically very similar to early tube amps. Also the so-called hybrid amps (tube pre-amplifier and transistor power-amp) are very popular when working in the preliminary stage with tube distortion, because having a transistor final stage keeps the amp pleasantly light.