Based on xotic BB Preamp/  Overdrive
MINI BB Preamp

Review by Talk Bass.com

Product Page

Demo by Fabian Lopes

Demo by ChoptonesOfficial

B-Box

4 Effects Pedal in 1 Unit  :
Overdrive ,LOOP,Chorus, Delay
Overdrive:
Based on the Timmy Overdrive  (two mode overdrive).
Chorus
Based on the Boss Ce2 Chorus,Analog bucket brigade (BBD) technology yields premium vintage modulation effects..
Delay:
Level: Sets the level of delayed signal mixed with straight guitar tone, fully CCW there is only straight (un-effected) guitar signal heard and fully CW gives the loudest delay.
FX LOOP
The SEND and RETURN jacks let you expand your board with other pedals .the FX LOOP point is positioned between the Overdrive And Delay modules.

Review by TDPRI

Demo by DanMusicPartner

Demo by The Rolling Store

Red Fox

Based on DOD250,DOD YJM308 ,MXR DISTORTION- circuit

Review by reddit /guitarpedals

Demo by LAAK MUSIC STORE

Demo by MOMO'S DEMOS

LM741 Preamp

XP Booster

Review by Medium.com

Demo by Dan Leggatt