I've having some major issues with feedback from my DSL 100 half stack, which is weird because I've got a Boss NS-1 and an ISP decimator. My effects loop has the ISP in it at the end and the chain goes: Boss CH-1-->DD-6-->BBE Sonic Maximizer-->Boss Equalizer-->Decimator. Straight into the front end I've got my Keeley OD-2 into a Boss NS-1. I have no idea why the hum is so bad. It could simply be a bad cable, or the THD hotplate I've got. I'll have to investigate.