中身はあまり変わり映えしませんが、あれこれ実験して最もエグい音が出る順に接続してます。

in
providence / stb-1jb
(tuner, buffer, junction box)
from send
↓
panda midi solutions / future impact Ⅰ.
(bass guitar synth processor)
↓
maxon / cp9pro+
(compressor, limitter)
↓
mxr / bass octave deluxe
(octaver)
↓
mu-tron / micro-tron Ⅲ
(envelope filter)
↓
darkglass electronics / vintage micro tubes
(overdrive)
↓
keeley / super mod workstation
(modulation×2)
↓
keeley / delay workstation
(delay, reverb)
↓
to return
providence / stv-1jb
(tuner, buffer, junction box)
out

ちょっとカッコつけて撮影してみました（笑）