I replaced/upgraded the two main filter caps to 5600uf Nichicons in place of the stock 4000uf as well as a few others that were iffy. I fitted some higher quality speaker binding posts, a 16g polarized power cord, and a much needed on/off switch. A couple dings but only if you look really close. Amazingly impressive amplifier, about 201wpc stereo at 8 ohms, 500w bridged mono at 8 ohms. I used it in bridge mode as a subwoofer amp into a 4 ohm load for a couple weeks in my system just to see what it was capable of. At very high volume levels it will dim the lights at bass drops on a 20 amp circuit and it won't even so much as break a sweat. I kid you not. Dead quiet and nothing wrong with it. You will not be disappointed and all mods are documented. Thanks for looking!