+1 for the Astron. Many on the TPA3116 thread have picked up used Astron RS20, RS 12, RS7 or SL 11. SL = slim line and RS are more boxy and not as wide. I read somewhere that model number with 7 and higher have better parts but don't know that for a fact. If you want to keep it small and lighter stay away from anything higher than 12. I got a slightly scratched up SL 15 for about $5 plus shipping from ebay but that took me a long time to find a deal like that (it was miss marked and almost looked like it was broken). You can find a RS7 between $10 to 30 if you look for a while on ebay and craigslist. They are heavy so shipping adds up. Good luck!