Owned this for years.  Like the SD-1 you have to use it properly.  We used these in the 80's in front of JCM 800's.  The early JCM's at max gain and club gig volume were very crunchy, no insane gain on their own, and the DS-1 pushed it to high gain.  That's how you use these classic pedals . Same with the SD-1 you used it to push crunchy tube amps.  The SD-1 had a softer clip  and the DS-1 has a very hard edge to it. Don't buy these to play on a clean channel or even worse on a Solid State amp.  These are for pushing tube amps over the edge and they do it well.