Before revision: A Bitstream or 1-bit DAC is a consumer electronics marketing term describing an oversampling digital-to-analog converter (DAC) with an actual 1-bit DAC (that is, a simple "on/off" switch) in a delta-sigma loop operating at multiples of the sampling frequency.
After revision: A (sometimes called Bitstream converter by Philips) 1-bit DAC is a consumer electronics marketing term describing an oversampling digital-to-analog converter (DAC) with an actual 1-bit DAC (that is, a simple "on/off" switch) in a delta-sigma loop operating at multiples of the sampling frequency.