Finally built one of my PPAS boards and cased it up in an aluminum stomp box, pictures are in the big post pics thread. Here is my configuration for anyone curious:
R1/R1G/R4G - 4.42kΩ
R2 - 1MΩ
R3 - 402Ω
R4R/L - 2.21kΩ
R5 - 4.02kΩ
R6 - 1MΩ
(I believe I managed to find .1% vishay in all these values at mouser)
Gives the following specs-
Outer Loop Gain - 6.47
Inner Loop Gain - 249.76
Total Gain - 6.322
AD8620/10 GBP - 25Mhz
Amp Bandwidth - 100kHz
Full volume offset is around .1mV on the left .6mV on the right. The amp consumes right around 16.5 mA of current with the buffer bandwidth jumper position open.
Build impression - Build is fairly simple for someone with building experience. Not the ideal intro to SMD with 0805 resistors but for someone who has worked with 1206, there shouldn't be much trouble. I don't know if there is a guide to building this, but I found it easier to solder on resistors, diodes, and jfets before the opamps and the smd capacitors. The soic parts are actually some of the taller components on this board and reaching over a 0805 or even 1206 resistor to get to the soic leads seemed less of a pain in my ass than having the ICs in the way of the resistor pads. Of course the through hole crap goes on last.
On a side note, I squeezed the 16V 180uF (6.3x15) Nichi UPWs in the spot for the 10v 100uF caps (5x11) so I could use a 24v steps to run the amp while charging if needed. This means that the 25v 120uF UPW will also fit and give an extra measure of safety should the rail splitter fail and hit those caps with full rail.
Listening Impression - Well its AD86x0 through BB buf634s. If you've ever heard a Pimeta with the same setup, expect much the same. The buffers smooth out the 86x0 pleasantly. I could not tell any difference in sound with the buffers running in high bandwidth so I opened the jumper back up again. I ran it A/B next to my PINT and it would be cake to pick them out blind. The PINT has a fuller, though less precise, bass and a more forward midrange, the overall sound seems slightly blended together. The PPAS has a slightly thinner sound overall with much better instrument seperation, more sparkle on the highs, and a very precise, well defined bass through midrange. I am quite impressed by the last. The smearing/blending on the PINT may be caused by the input caps where the PPAS really doesn't have any caps directly in the signal path. Seeing as how these are portable amps, I would have to say the dealbreaker for the PINT is current consumption as it uses nearly 3x the current of the PPAS.
Impressions are with K701s and my modded av710. Tomorrow I think I am going to pick up a pair of UE IEMs to give a try seeing as I can buy them locally and shouldn't have problems returning them if I hate them. If anyone can point me in the direction of some IEMs sub $300 that have a sound signature close to K701s...