It sounds good when used on the top boost amp channel and pushing it even harder, but frankly I think it sounds best when used simply with a good clean tone on the amp

You CAN simply plug into it and use it alone with a clean channel.

The SD-1 is a staple in my effects chain - there are overdrive pedals on the market that have a wider range of sounds if you are able to afford paying $200-$300, but if you're looking for a warm overdrive while using clean channels or just wanting to add a bit more crunch to your already overdriven amp the SD-1 is a great choice.

Nice tubish sound over clean channel even better over distorted channel got it in line with my ts7 and ds1

Adds a little dirt to the clean channel on your amplifier

I actually bought it with the intention of boosting my high gain channel for solos (my tone is like a modernized version of old school heavy metal) and it was not for that at all

You will be disappointed if you think you can run this into a clean channel and pull off Raining Blood

I bought this pedal used and have used it with both a Fender tube amp and a Marshall solid state using clean channels