In total, up to four inputs are possible. By default, the unit has two digital inputs and one analog input (“reference” only). Optionally, a third digital or a second analog input can be added. The formats can be selected flexibly. All common standards are available: AES/EBU, BNC, Cinch, Toslink. In addition, there is “arfi-optical” for connecting our music server mu-se or the external USB modules.