Hartke HD75

SIMPLE:
it has everything needed on a combo amp of this category.
The Input perfectly works both with passive and active bass.
The Bass, Mid and Treble knobs (cut or boost) give a great control over the tone, but in case of more specific needs on the frequencies, there's a 7 bands graphic EQ to go a bit deeper into the sound shaping. Both EQ sections (knobs and sliders) are very effective and can provide a lot of cut/boost headroom on each corresponding band or single frequency - no need to cut or boost too much with the sliders of the graphic EQ in order to get a good result. Just I would have preferred to have an ON/OFF button on this EQ section.
To connect all the pedals of my board into the rig there is the SEND/RETURN section. Nice to have it!
Unfortunately there isn’t a Direct Line Output... It would have made this amp really complete.

POWERFUL:
a lot of power, I am quite surprise of this baby!
Warm and well defined sound (thanks to the materials used in the woofer, as claimed by Hartke itself).
Great low end and a lot of headroom to push up the sound, very good versatility with the 2 above mentioned EQ sections. And the output level is always kept under control by the internal limiter: that's really a great feature and it definitely works pretty well !

EFFECTIVE:
Just simple as easy to use, with a general linear sound that respects the character of the bass plugged in (it doesn't add any particular color to the sound of the instrument).
I think it provides great performances in all its features and commands.
Not very portable, quite heavy. And I don’t like the uncomfortable handle on the top. I would have preferred 2 handles on the sides, that better prevent back pain accidents if you need to often move it (fortunately that’s not my case with this amp ; )