Module A-138d can be used in two different ways: 

- as a crossfader module within the A-100 

- as an insert module for external effect units (e.g. guitar stomp boxes) with dry/wet control 

technical details

Width: 8HP 

Connections: 
2x Audio input 1 
2x Audio input 2 
2x Mix output 
FX Send (6,3 mm) 
FX Return (6,3 mm)