I ordered and received the 200W with 6dB boost model, strictly for evaluation. Mainly I was looking to see if I can figure out the boost circuit, and identify the components needed for tweaking the subsonic filter for diy needs. Sadly, these amps are not DIY-friendly at all, so imo are not worth the trouble unless they fit your needs 'as-is'. Yung has taken some measures that make board removal tedius, and obviously warrany-voiding. Gluing the board in place, and using surface mount resistors that can only safely be replaced by removing the board, for example. Still, I will do my best to figure out the boost circuit, for those brave souls who spit in the eye of challenges like this. Or if someone out there happens to already have the schematic, even just the pre-amp, that would be awesome to share.
The amp itself seems to be very well made. I'll eventually give it a listen. I was surprised at the small size, even knowing the dimensions before it arrived.
For me, I'll stick to the BASH amps since the info for these is already available, and they are relatively easy to tweak.
EDIT: After studying and working with these a bit more (and having my frustration of disassembly subside a bit), I've changed my mind about these. It is possible to tweak the HPF on these relatively easily if desired, and it is possible to defeat the bass boost circuit if needed. And I do like their smallish size, and good power. You can read through the whole thread to see how the circuits were discovered, or jump to post 85-ish for a wrap up.
Edited by garciab - 12/30/12 at 11:25am