One Control Minimal Series White Loop

>Use
For recording studio.

>Connection
Input: Guitar to Chain of analog effects.
Green loop: class A Fender Tweed preamp + Modulation effects
Red loop: Diezel VH4 preamp + Modulation effects
Output: Mesa power amp + Palmer 2x12 Closed Back Cabin

>Facts
I have noticed that noise is being induced from Green to/from Red loops. I use an isolated 9 volt DC adaptor, as for each loop's chain of effects; none of the two extra 9V DC / OUT are being used. Still, ground, hum and hiss affect the Output signal.

>Test
Input: Guitar
Green Loop Send: none
Green Loop Return: out from chorus pedal with 9v batt
Red Loop Send-Return: sealed jumper cable
Output: Amp
Procedure: turn on the switch, set loop red (jumper), turn on the chorus pedal, listen to how the Amp captures the signal effect from the chrous pedal even while a different loop is being used. turn off the chorus pedal and unplugged it form the device. listen how the guitar signal is affected by the loop, even while using a jumper cable (buffer?).