Hi.
This preamp add a great distortion when the knobs are turned all the way up, and there is a lot of different sounds playing with the gain and volume controlls. It can go from a clean, sparkley sound to a classic rock-type distortion/overdrive. I guess it sounds a lot like a hiwatt, and when cranked it sound like a tube-amp pushed hard. I really like the sound of this, but I really wish I could get the presence-controll to do something. I don't have a lot of time to work on stompboxes these days, but when I'll get the time I'll try to get the presence to do something.
Running this on 18 volt would give you a lot more headroom, giving you less distortion at higher volumes. Running this on 18v I guess this will be a really good tube-like preamp, giving a great breakup ehen pushed. I'm planning on trying this when my Lm1875 amp is finnished.
I changed the Gain and Volume-controlls on the schem and layout, but they should be 500k as they were on the first schem. The reason I changed them was that I had misswired the pots, so they didn't work propperly.

When wiring things up the right way, 500k turned out to be theperfect value.
Even if the precence controll doesen't work at the moment, I encourage you to build this. As soon as I get the presence controll to work, it will (hopefully) only be a few components that should be changed. I would really like the feedback from someone who knows what a Hiwatt sounds like.
I finnished the box for this earlier today, so I'll post pics and soundclipps when it's finnished.