Can I use the TC Spark Booster with an electro-acoustic guitar ? Will I get a clean volume boost without distortion?
Yes, you can. You will get the advantage to reduce the level differences when you want to go from hard strumming with a pick to a quiet finger picking song. In this case, you need to increase the volume of the guitar on stage, without having to get the attention of the sound engineer running the mixing console to do it.
Be careful to keep the mini toggle switch to the center position on "CLEAN". Be careful with the GAIN knob as well. Do not turn it more than the quarter, so 9 O' clock, 10 O' clock maximum, otherwise you will get some distortion. If it is a sound sought by electric guitarists, it is leaking by acoustic guitarists ! Set well the output level from the preamp of your guitar. You can adjust the output volume with the "LEVEL" knob of the Spark Booster, depending the output level of your guitar and the device you input with the Spark Booster.
You can adjust the tone controls on the Spark Booster, "BASS" & "TREBLE", but do not forget that you already have these controls on your guitar. Often with a middle (or a parametric) control in addition of the bass & treble.
A last thing, the Spark Booster does have some color. Many users say they like the color so much that they leave it on all the time. Keep in mind, those are electric guitarists. Try, explore, be careful with the settings and at last, you will get an original sound with a special way to use the Spark Booster.