in simple words, preamp is a EQ like instrument that is connected to an amp for us to control the type of sound we want in the car...like bass, treble, mid and so on....

it is connected in between HU and amp, hence the name preamp....connection before output goes to amp and not after...

i heard caliber is local cap ayam brand ...i also have one but havent use yet cos no amp ...preamp i think any brand will do the job OK.....

correct me if im wrong sifus...

i agree with wat u said above .....if u wanna SQ, better not tune it using preamp...

i think its better to say beginners...hehehe ....after all, not everyone is born smart and goes to ICE kingdom the hard way .....learn from the bottom lor, try on stuffs if u have money...