I am about halfway through my electronic engineering degree with 8 years of amateur experience in circuit design, build, modification and repair.
Internally, this is a decent quality unit.
It is loaded with 4558’s which is the most popular dual op amp. While NE5532’s are much better, it’s not a major factor due to the overall circuit architecture being so extravagant.
First, the sub crossover.
Lots of boost, fair amount of options and a lot of output. It’s far better than majority of your amp’s onboard crossovers. Variable cutoff point with variable selectable bass boost and variable boost level as well.
Lots of headroom, lots of performance.
Rear channel crossover offers 6-12 dB slope. 400 Hz and below cutoff point which is ideal. Lots of output and it’s designed with the rear speakers typically having more enclosure volume that front speakers.
Again, good headroom, lots of output and more than you find on most amp’s built in high pass crossover.
Front channel takes it a step further.
There is a multiplier so you can cut off at 250 Hz or 2500 Hz. Again, 6-12 dB selectable slope. Good headroom and plenty of output.
Structurally it’s your typical sheet steel. Decent quality, nice silk screening for the control panel. Unplugging power, ground and remote terminal block to make installation or servicing less troubling.
Overall for the price, I doubt you will find equal or better. Even at double the price, many designs will be about the same as this but a better quality PCB and more expensive passives. Actives will always be standard grade fets and your the craptastically popular 4558 or TLC07’s which really need to be cast aside and the 5532 standardized.