It's mod'ing time!
This is a great how-to modifying your Boss SD-1 by Teppo Gustafsson of MIA
How-to step by step on installing a Pedaltrain Powertrain 1250 as a second power supply to a Pedaltrain PT-2 pedalboard
Review of the Pedaltrain Powertrain 1250 power supply. A great / clean power supply for your board - and install procedure!