How to noise test your gear

In this example I am referring to a guitar rig but it will work on a bass rig or larger keyboard rig. This test will help you find the weak link of your setup. Make sure you do this test in a quiet place. Maybe at a rehearsal studio before the rest of the band shows up.

Step one

Connect your amp to a grounded outlet. Plug in your guitar directly to the amp with your favorite guitar cable and play some chords at your normal (loud!) rehearsal volume. Turn down the volume on the guitar to zero and place it in a guitar stand. Now, listen to the sound coming from the speaker. You should hear a low hum and low noise coming from the speaker and, if it's a tube amp, a low acoustical hum generated by the output transformer inside the amp.

This is the lowest noise level of your setup. From now on, every stomp box and cable you add to the signal chain will add to the noise level.

Step two

Put fresh batteries in your pedals and connect them between your guitar and amp in the order you prefer. If some of your pedals need a wall wart transformer, use the right one made for that pedal. Make sure to use short guitar patch cables. Put all pedals in bypass mode.

Listen to the sound coming out of the speaker with the guitar volume still at zero. This is your "second" noise level.

Now, if possible, run all your 9-volt pedals on a power transformer instead of batteries. Even more noise and hum?

If so, you may have a ground-loop problem and you need help with finding the right transformer for your pedals and / or help with the cabling.

Step three

Turn on your favorite pedal at its regular settings and listen to the added noise. Is it acceptable?

Step four

Just hold your guitar without playing (dampen the strings) and turn up the volume to maximum. Now you will definitely hear more noise and hum coming from the guitar pickups.  Move around the room with your guitar and the noise and hum will shift in level. This is natural and is depended on the type of pickups you are using and on the environment (lights, monitors and under floor heating etc). This is your loudest noise level when everything is it sounds when you mute the strings between a chord and a note.

Step five

Play something on your guitar and listen to how the guitar sounds.

Tweak the EQ on the amp to get a sound you are comfortable with. Do you manage to get the sound you want?

Enough bass, middle or treble? Bad cables can make your guitar sound dull so you instinctively raise the treble on your amp and at the same time you will bring up the noise. Which order you patch your pedals in can be very personal. It can make or break your sound.

Here you need to understand what pedals with a "true bypass-switch" do or not do. Also how buffers and cables "colour" your sound.


When keeping the noise level at a minimum, using the right power transformer and cabling strategy, your sound will come out cleaner and stronger.

SOS can help you improve your sound through all five steps.

©  Göran "LEO" Elmquist, Sound Of Silence - 2010