4Rear panel features introduction2 channel versionshown with NeutrikSpeakon outputconnectorsDSP controlPortXLR connectors forinputs and loop thru4channel versionshown with NeutrikSpeakon outputconnectorsOutput ConnectorsInput ConnectorsAudio inputs-4-channel modelsAudio link:the signal input into channel 1 can be output fromchannel 1 only, similarly, the signal channel 3 is the same.Mains input200V-240Vor 100V-120VoperationRS-485USBNETSANWAY AUDIO http://www.china-sanway.com