After 6 months with the GFI Synethesia, it's probably the best modulation pedal I've ever tried : r/guitarpedals
GFI System Synesthesia | The Pedal Zone
The ONLY Modulation Pedal You Need? | GFI System Synesthesia Dual Channel Modulation | Pedal Demo - YouTube
Andertons Music Co. - NEWS: GFI System releases the Synesthesia, the ultimate multi-modulation machine! With a flexible dual-channel design letting you use two of the pedal's 22 effects simultaneously, the Synesthesia offers
GFI Systems Synesthesia Dual Engine Modulation Effects Pedal : Amazon.co.uk: Musical Instruments & DJ