Where can I Buy one set?You picked a good one to learn on. Q1 & Q3 are leakage-biased. Q1-E and Q3-C should be somewhere between -3V and -6V. The collector voltage on Q2 varies with the ATTACK setting. With ATTACK at zero, Q2-C should be near -9V. With ATTACK at 10, Q2-C should be somewhere in the middle, depending on what sounds good to you. Part number is unimportant, leakage and hFE are what matters. I agree with Mir9, buy a transistor set that was selected for a Tone Bender MK1. Otherwise, you will need to buy a bunch of them and select them yourself. Definitely install sockets.