Okay, let us quickly discuss the quality and look the the mini Spark. It's well built, don't get fooled by the small box design. The layout is awesome and i must admit, it is one of the most beautiful looking pedals I have in my collection. Soundwise it is a one trick pony, of course. It's your decision if you want to put it in front of your overdrive, which increases the overdrive ratio, or if you want to put it behind your overdrive, which leaves the overdrive ratio untouched, but increases the volume. This little pedal is loud - really loud. To boost solos, it is absolutely sufficient to out the knob on 9h. But beware, The pedal is not too noisy. With a strat you get a nice growl a la SRV and the Les Paul gets tickled enough to deliver some very smooth overdrive. The pedal leaves your signal intouched and it doesn't change your initial guitar sound too much. In fact it highlights the guitar's character very well. Overall, it really is a very good boost pedal.