Great sounding pedal. I used BC407s for the Transistors. It gives a really nice full sound Fuzz that's not too bottom heavy. It has very nice breakup. I'm glad I went with the BC407. Internals are a bit of a mess as the PCB was made for 1590a with small pots and I went with a 1590b with large pots. I put the jacks all on top as I love using this with the 1590b. It saves a ton of space on the board but you need to be really careful with where you place your holes.