The DSP (Digital Signal Processing) amplifier is a better/more powerful type of amplifier. So in this case (as per OP's photo) they are combined. But I believe there are Carver amps for the e85/e83 series which are not DSP. Not 100% sure but I assume that DSP was only in the cars with sat nav? And non-DSP Carver was just the business stereo where you had the 10 speakers.