how I use boost pedals September 19, 2007Posted by Phillip in Amps, Effects, Guitar, Live Sound, Music.
There are a couple of uses for boost pedals. One use is to create a pure volume increase without changing your basic sound. Another use is to push the preamp section of your amp to create a more distorted tone without drastically effecting the overall tone of the amp. I want to focus on the second part.
There are two stages in which gain is added to your signal in a guitar amplifier. The first is the preamp stage (12AX7, 12AT7, 12AU7, etc) and the second is the power amp stage (EL84, EL34, 6L6, 6V6, etc). If you have a master volume control, you can crank the gain and turn the master volume down. This causes your preamp tubes to get hot and start clipping, while your power amp tubes stay relatively cool. I don’t have a master volume on my amp, so the details on your setup will be a little different if your amp has one.
I start by turning the amp up to about 1:00 on the gain knob. As I mentioned, I don’t have a master volume control, so my volume increases as the gain increases. This setting allows me to play lightly and get a nice clean tone, but I can also hit the strings harder and get some crunch.
Stepping on a boost ramps up the signal that I’m sending to the preamp. When this beefed-up signal hits the preamp, it causes it to clip (or distort) more than it did before. If I had my amp on a lower gain setting, or if I had an amp with more clean headroom, the boost would simply increase the volume without adding any gain.
Basically, I’m using the boost as a kind of distortion pedal doesn’t color the basic character of my amp too much. Does that make sense?