I have a Vox AC4 amplifier which lack of FX loop.
Hence, it is possible to add the effects only in front of the amplifier. The chain would be: Guitar --> looper --> Reverb --> Amp
Because the looper is in front, it is important to match the impedance for the rest pedals:
From the looper I will have 330Ω of the output
HolyGrain which is stomp box has 680.000 Ω on input and 360Ω on the output RV 300 which is modulatory pedal has 250.000Ω on input and 1.000 Ω on output
What is the better option assuming that I would like to send to Ac4 a very undisturbed in terms of frequencies range signal and ii) not lose the amplitude of the signal because AC4 lack of the head-room ?