If you are looking to get drive from preamp distortion you most definitely want to use your Screamer as close to the beginning of the signal chain as possible. Preferably, the first pedal in the chain as it will interact with your pickups in a positive way. You may however want to use a tuner or buffer to change the signal impedance from high to low. This eliminates tone degradation over long cable runs or through multiple effects circuits. Circuits that are not true-bypass will generally buffer your signal. The tone will be different than a non-buffered tone though. If you use active pickups then they are already buffering the signal and converting it to a low impedance signal. You might want to try several configurations to find the best tone for you. In my opinion, the best way to go is to have your OD/boost pedal first in the signal chain coming out of your guitar. It will make the signal low impedance, if you are using passive pickups, and allow you responsive shaping properties with the tone knobs similar to using active pickups. Even boutique pedal builder/modder Robert Keeley suggest putting a good OD before a compressor in the effects chain. Check out: http://www.robertkeeley.com/manuals/keeley_compressor.pdf
Scroll down to the "input" part of the instructions and read down. Robert has been instrumental in my guitar tone. He is truly a phenomenal talent in guitar tone technology.
So go: OD/boost>compressor>wah>filter>modulation>input. Put delay/time based effects into the effects loop. If you put a boost in the effects loop it will push the power tubes harder and make what you already have tonewise louder, but it always seems to sound like ***.
Good luck. Peace. :shock: :twisted: :shock:
