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,→Gain Staging
== Gain Staging ==
''Gain staging'' refers to setting the levels of each device in your signal chain to achieve the highest signal-to-noise ratio (SNR) while avoiding unwanted clipping (distortion).
Analog devices (and digital devices that emulate them properly) have a ''noise floor'' - a small amount of noise that is inherent by nature and cannot be reduced. Running your devices to output at maximum strength means that the signal is much higher than this noise floor, maximizing signal-to-noise. (Devices have other forms of inherent noise that will increase with certain settings and output levels, but we are only concerned with the signal level vs. noise floor here.) Depending on the settings of the device, maximum output may be too strong for its internal amplifier and clip it. Then output should be reduced to avoid clipping.
Usually devices are designed with enough headroom so that their internal amplifiers don't clip, even at extreme settings and max output. However, when creating a whole signal chain, several devices that can boost the signal connected together are very likely to clip when they are all set to maximum output. Proper gain staging dictates that each device should have the maximum output to not only avoid clipping its own amplifier, but also the input buffer or other uncontrollable aspects of the next device in the chain.
The way you have to test this all out is by using a completely clean tone. If there's any distortion, you have to turn down one device at a time to locate the source of the clipping. Many times you want a distorted tone, which can mask unwanted clipping and make it difficult to tell where it is in the signal chain. You have to listen with a very careful ear, or substitute distortion for a clean tone of approximately the same volume level.
Let's look at an example signal chain:
Guitar > Compressor > Distortion (as boost) > Pre-Amp > Chorus > Delay > Power Amp > Cabinet
We start with the pre-amp and power amp - those are the only parts of the chain that ''have'' to be on. Everything else is set to bypass or removed from the signal chain for now. We set the pre-amp to a clean channel, minimum drive (if available), and a conservative channel volume. We set the master volume of the amp somewhat low - loud enough to hear but the tone should still be clean, definitely far below the amp's clean headroom. This is our baseline to set up at least the stomp effects (before the amp).
When we first turn on the compressor and distortion, we will likely need to lower the distortion's output level to about 50% or less to prevent it from clipping the pre-amp. Ultimately, we ''want'' it to do exactly that, but for now it will only interfere with being able to hear clipping in other devices, so we keep it low enough to avoid clipping. Once we've set everything else up, we can crank it back up.
The compressor will likely end up boosting the signal. We are using the distortion pedal as a boost only - we don't want it to clip internally. After we set the distortion's drive knob to minimum, we slowly turn up the compressor output from minimum until we start to hear some clipping. The compressor is likely clipping the distortion, but the distortion cannot be set any lower, so we need to turn down the compressor's output. Do so until all clipping is removed, even when playing accented notes and chords (or however you intend to play with those effects turned on).
Next is the chorus and delay. First keep the delay off. We need to make sure the amp's effects loop send isn't clipping the chorus. Many amps have an effects loop send volume control, which we can use to prevent clipping the chorus. If not, we likely have to use the amp's channel volume control. Once we've set the chorus, we can do the same thing with the delay, reducing the chorus's output if the delay exhibits clipping. If the chorus doesn't have an output control, we will have to go back a stage to the effects loop send volume or amp's channel volume - it's unfortunate, but it's the best we can do.
Once everything is dialed in for no clipping, we can switch the pre-amp to a distortion channel and crank up the distortion pedals output level to maximum. Then we set the channel volume on the pre-amp to approximately match the volume we had on the clean channel. If done correctly, there shouldn't be any unwanted clipping in the signal chain.
== Dialing in Distortion Tone ==