"S O'Neill" wrote in message

Arny Krueger wrote:

A DSD data stream is composed of pulses that are basically
integrated to produce an analog signal. Pulses have a value of
either +1 or -1. Alternate pulses with opposite polarities sum out
to zero. If the pulses are predominately +1, then the integrated
signal goes positive. The more predominately the pulses are +1, the
faster the integrated signal goes positive. If the pulses are
predominately -1 then the integrated signal goes minus, and so on.

Didn't that used to be called 1-bit DPCM?

Here are block diagrams of a DPCM coder and decoder

http://ce.sharif.edu/~m_amiri/Projects/MWIPC/dpcm1.htm

On page 7 of

http://www.hit.bme.hu/people/papay/edu/Acrobat/DSD.pdf

there is a block diagram of a DSD decoder.

Don't look the same to me.