Cambridge - Azur 851A Integrated (Black) Proprietary Class XD technology Two oversize audiophile-grade toroidal transformers - one for the sensitive preamp section and one for the power stages Two main types of connectivity: RCA/Phono inputs, and two pairs of fully balanced XLR connections CAP5 protection technology for trouble-free operation and to prevent clipping and DC overcurrents Acoustically damped full-metal chassis with a thick, brushed-aluminum front panel