Summing 2 Inputs to a Pedal, DI or Splitter

[familyortiz]

Hey, I have used a simple input stage which combines two input signals, has adjustable gain and is a nice addition to a DI, pedal, or Splitter box. The input connection can be a stereo 1/4" or 2 mono 1/4" jacks and it does not matter if one channel's connection is left open, i.e. no problem inputting a mono plug to the stereo jack. My original design was for a DI box with 2 channel input, for summing 2 acoustics. I realized that this input stage could be applied to summing 2 inputs to a pedal or splitter box to reduce the overall stomp boxes needed for 2 inputs. Using 2 inverting stages I retained the input phase.
The opamp symbols are for generic use so please disregard the pinout numbering. cheers