edit: check out the new UDP80: http://hifimediy.com/news/fully-digital-amplifiers
We are excited to introduce the UD80 digital amplifier, the UD20's bigger brother! UD80 is powerful with up to 2x80W @ 8 ohm, and while UD20's bass is on the lighter side the UD80 has a deep powerful bass. It still has that ultra clear audiophile sound quality. We are really excited about this amplifier and we think that you guys will love it!
UD80 is built on the same technology as UD20; they are both digital PWM amplifiers with no A/D conversion, no preamp or any analog signal path anywhere before the output stage. This makes a very direct link between the digital source and the outputs going to the speakers, creating a very clear audiophile sound.
It can run on a wide range of voltages from 10V to 36V. Power requirements and output will vary depending on load:
8 ohm loads: 36V 6.3A, 2 x 80W. Minimum distortion is achieved at 36V. The amp can also be powered from lower voltages with good result. Around 2x60W from 30V supply and 2x36W from 24V supply. We have been using it with The 0-32V adjustable power set at 32V.
4 ohm loads: 21V 7A, 2 x 50W. Minimum distortion is achieved at 21V. 7A is required for 2 x 50W @ 4ohm. You can use any power supply from 21V to 36V with same results, but 21V 7A power supply will be cheaper than 36V 7A power supply.
USB is asynchronous and utilises the SA9023 chip from Savitech. It supports 96Khz and 24 bit without drivers on mac, windows, linux. it also works with iPad 3/4 with the USB hub.
It's ready for shipping in a couple of days (however some power supply options are still not ready).