[JeffB]

I have spent the last couple of days searching for an amplifier that keeps the signal in the digital domain as long as possible.
It should take spdif or some other digital input and use this to convert directly to pwm to drive the amplifier.  I have been unable to locate such an amplifier.

This path seems somewhat problematic though for distribution of the spdif signal.
I could imagine wanting 5.1 with 6 monoblock amplifiers and the corresponding digital cross-overs.

I was looking at the M-audio EX66 studio monitor and this takes an spdif input to drive a digital amplifier.
I don't know whether it converts to analog and then to pwm though.

[dwk]

This is how the TI Equibit technology works - direct translation of PCM to PWM, with an open-loop output stage. It is found in the Tact amplifiers and the Panasonic XR series receivers - lots of information out there if you search.

Using them in a digital xover setup is complicated by the fact that there is no standard for transmitting uncompressed multi-channel audio. Each Panasonic reciever for example can only accept stereo PCM or else DD/DTS multichannel.  You'd need say 3 receivers and a soundcard capable of 3 pairs of spdif outputs to implement a digital xover this way.

[Feisal K]

the XR57 (XR59 in Europe) and XR700 take HDMI inputs

unfortunately there is no EQ i know of that has HDMI I/O