If you suspect the noise is coming from Le Preamp, the first thing to do is to remove any other potential noise sources from your system. Just plug your guitar directly into the Input of Le Preamp, and monitor the result directly through its Headphone output. Alternatively, you can use the XLR DI Output or 1/4″ Output jack connected to a headphone amplifier, sound interface, mixing console or any other monitoring system. In which case, make sure this monitoring system is as noise-free as possible. If doing this stops the noise, then it probably means the noise comes from something else in your system.
One important thing to do is to check if the noise comes from your guitar. Turn down the volume of your guitar or unplug the Input jack from Le Preamp: if the noise disappears, it means the noise comes from your guitar. Le Preamp offers gain ranging from modest (Le Clean) to huge (Le Lead), which means it will amplify any noise coming from the guitar, potentially to a point where it becomes distracting. Single-coil pickups are more susceptible to floor noise than humbuckers, which are specifically designed to reject them. On a guitar with several single-coil pickups, it is sometimes possible to connect them to get a noise-cancelling effect similar to a humbucker: don’t hesitate to try several positions with your pickups selector switch. Noise picked-up by the guitar can sometimes come from light dimmers, refrigerators, computers, or other appliances. You could try turning off as much electrical appliances as possible, or moving away from them, maybe change rooms as well… This won’t necessarily be a viable solution, but will give you an idea if your environment is a factor in the noise issue.
Note: in this situation, the noise could also come, partially or totally, from your guitar cable. You should always check with other cables to make sure you’re not using a bad cable. (See point 5 for additional information.
A good quality power supply is important to get a noise-free signal. Nowadays, a lot of pedalboard power supplies are available, and most of them work very well, but we can’t guarantee how Le Preamp will react with each and every one of them. If you are using an after market power supply, try removing it and using the power supply that came with Le Preamp. It was carefully selected to insure good performance of the unit.
If you have checked all this and the noise is still present, then it probably comes from Le Preamp. Like every circuit that generates gain, Le Preamp does produce a small amount of noise. Fortunately, this can usually be dealt with easily. The key is to maximize the signal-to-noise ratio, by following a simple rule : keep the signal as high as possible without clipping. Here is how to do this:
Le Preamp features one or several gain stages (depending on the model), controlled by the Gain potentiometer of each channel. This Gain setting is mostly used to shape your tone : on Channel B this is obvious, in Channel A this is more subtle but still very important. This is of course linked to the noise ratio (the higher the Gain the higher the noise), but the Gain setting is first and foremost a tonal adjustment, so just set Gain to get the tone you want.
However, you then have the Volume control which is dedicated to setting the level of the signal, and nothing else. In standard situations, Volume won’t have much (if any) effect on the tone. This means you can (and should) use it to set the actual level out of the unit. You should set it as high as possible, as long as you don’t overload the output stage of Le Preamp and/or the input of the product connected after it (or in its FX Loop). When you overload the output, you will usually get a very hard type of saturation or clipping: don’t mistake this for tube distortion ! If this happens, first try first lowering the input gain of the unit placed after Le Preamp. If this is not possible, then lower the Volume.
Note: the signal-to-noise considerations are also true before and after Le Preamp. By adjusting levels between each link in your whole signal chain, you can usually reduce noise by fair amount.
In some situations, all the advice above won’t be enough, and you’ll need something else to help. It’s then probably time to use a very useful tool : a noise gate.
If your noise gate only has an input and output, place it:
– before Le Preamp for optimal control. This is probably the way to go if you found out at point 2 that the noise comes from your guitar. Downside of this placement: it could not bring enough noise reduction.
– after Le Preamp for optimal noise reduction. Downside of this placement: it could be harder to control.
The best results are obtained with noise gates that feature a loop. If you have one of these: plug your guitar (or clean signal) in the input, and put all your noisy stuff in the loop. The gate will be controlled by the clean guitar signal (which means optimal control), but the signal will be cut after the noisy stuff (which means optimal noise reduction).
Finally, if you think your Le Preamp is abnormally noisy, it could be a fault of the unit. In which case feel free to contact us for technical support.