She's a beaut!

[Edalicious]

I've just gotten it breadboarded up! This is my first ever attempt at a pedal and it's worked a charm, despite not having all the right components. The instructions are all very clear and concise, so thanks Gaussmarkov for that!

My gain is a little bit low though, but I've got a 1.5kΩ resistor at R7 and a 220nF cap at C4, could these be the problem? And if not, what effect will those substitutions have on the pedal?

Also, I wasn't sure which pot to put where so I've got the 100k as gain and the 50k as volume. Is this right and if not what difference is that making?

[blackcorvo]

1.5kΩ is a bit too big for R7. The original is 100Ω!

Try switching the potentiometers. The 50kΩ is for the gain and the 100kΩ is for the volume.
If you think you need more gain, try changing R4 to a lower value (the original is 4.7kΩ. try something like 3.3kΩ, 2.7kΩ...).

About C4, try other values. Just tweak it till you find a sound that is nice to your ears