Spent the last 90 minutes reading TI's docs, and comparing their reference design to the pictures on Class D Audio's website. Seems TI has done a very good job designing the chip which is the core of this amp. Leaves very little room for mistakes from the implimenter. The only thing TI stresses is the distance from the output pins to the decoupling caps. TI says this should only be limited by the size of the heat sink. Looking at Class D's picture, that's exactly what they've done, the caps are right next to the sink.
That makes me feel much more comfortable in picking one of these up without someone else testing it first.
The only place Class D's design differs from TI's, is TI uses two separate power supply inputs. One (50V) for the output drive, and the other (12V) to run the chip. Class D takes one, and performs "house keeping" on board to step the voltage down to power the chip. TI's design is intended to be used with TI's class G power supply (variable output for different amplifier demands). Class D Audio's power supply is of a more traditional fixed level output.
I also noticed that Class D's kit includes a transformer in that $235 price. So that's amp board, power supply, and transformer. And from the looks of things, it could actually be assembled with no soldering. It's really just running wires between the parts, and tightening screws to hold them in place. Of course if one wanted nicer RCA or XLR inputs jacks would have to be connected to a couple of those wires.
EDIT: I should have noted that the proximity of the caps to the output pins is what is keeping the electromagnetic interference to a minimum. And safety features in TI's design keeps the output MOSFETs from conducting DC during power up/down.
Last edited by ClubNeon; 01/19/10 04:47 PM.
