Having lived with a Catalinbread HyperPak for a while, I was thinking it could do with having a bit more umph in the lows (to use a technical term) - I love the tone and it's pretty good as stock, but could it be improved? Enter one Silent Fly (www.sfxsound.co.uk), who said he could definitely help. I sent him the pedal and he modded it the day he received it - said he had other things to do but couldn't resist! He sent it back to me the next morning - that's service for you. I've only tried it through headphones - and my small practice combo - so far, but I could here the difference straight away. (Can't wait to try it through my gig rig). Although I use it in a blendable loop, having more low end coming from the pedal - ie overdriven low end - is just the ticket and it sounds great with a pic or fingerstyle - just as I'd expected, having had this email from SF: "Now the low frequency response is much more transparent. I tried it with a 6 string bass and the pedal can manage the B string pretty well. I also checked the pedal with a frequency analyser and the pedal now can go much lower. Modding a pedal so small was a little bit of a challenge and it took me longer than I thought but I'm happy with the result." Oh, and it's also sprouted two rather fetching [sfx] decals... Nice. So an excellent job, a really fast turn around and an all-round great guy to deal with to boot. Highly recommended.