Payback Looper: Simplify Schematic?

[Jaicen_solo]

I'm looking for some help guys.
I'm currently (still) building Tonegod's Payback looper: http://tech.thetonegod.com/payback/payback.html

Looking at the schematic, each op-amp is biased individually using a pair of 100k resistors.
Is there any reason they could not be replaced by a single set of resistors set up to provide vRef at 4.5v??

That would very much simplify the layout and make it easier to build, which would in turn make it easier for me to find any other errors i've made