Bought this fuzz box and had a blast trying it on a friend's valve amp - But on my own, much smaller amp, it doesn't sound so great, so I'll be returning this one for no other reason than that it doesn't quite work for my setup.
Using this in conjunction with a volume pedal made it far easier to handle, allowing me to adjust the input volume without needing to fiddle with the volume knob. These pedals could totally benefit from an input gain knob, but that sort of nuance seems out of character for this device. (And if you're feeling up for it, it's probably not a hard mod to do).
This pedal is very, very loud. The master volume only needs to be at 9oclock to reach unity, so everything on top of that is just pure volume boost. I found that turning it up too much caused the amp I was using to struggle to keep up, but it's great to have that gain on tap - and the huge knob makes it easy to adjust while playing.
All in all a great sound which benefits a lot from having the correct amplifier to get the most out of it. A little bit of a one-trick pony, but with smart gain staging and using it in conjunction with other pedals it can be surprisingly versatile.