Why would you want to do this, given that most pedals have a level control, and I don't really see why you would want to boost the signal at the PSM-5.
Maybe you need an active guitar instead? Shorter Cables? I dunno.
The signal level at the 'SEND' output is LOWER than the signal level at 'AMP' output when they should be the same, regardless of either a pasive or active guitar being used.