behringer GMA 100 miniamp

[nikkram17]

hi guys.. can you tell me if i can mod my behringer GMA 100 mini amp into much louder sound? i want to change its speaker  into a 10" speaker 8 ohms and i want it DC powered.. its a 9V powered miniamp and has a ac adaptor input and head phones i just want it to make it louder and put in a hot cabs cabinet that i scav from my friend.. pls help me figure out how to make this miniamp turn into much bigger amp.. thank you guys..

[rnolan]

Short answer, plug it (headphone out) into your stereo (1/8" T/R/S mini jack to 2 x RCA (line in, aux in, cd in)) forget the 10"...
I like Behringers statement on their website "conceived by Behringer" what crap, it's a copy (conceptually/idea wise) of a Tom Shultz Rockman X100 except it's got a tiny speaker and no effects (probably doesn't sound as good either).  Hey mikkram17, sorry for the rave but Behringer (and I've bought a bit of their gear over time) are the masters of reverse engineering other people designs so I reacted badly to the "conceived by" statement.
It doesn't have enough power to run a large speaker at any usable volume (it's got headphone outs) so your idea of a 10" speaker could be achieved but you'd need a power amp (hifi amp will work BTW) to drive the speaker.  You can take the headphone output and plug it into other inputs (e.g. line in, aux in, CD in) with the appropriate cables (e.g. stereo T/R/S 3.5m to 2 x RCA) and keep the volume down (or you'll distort the inputs).  You can also plug it into 2 guitar amps (cable 3.5m <> 2 x 1/4" jacks) e.g. I used to run my Rockman X100 into 2 Marshalls and I installed a couple of resistors (as a voltage divider) in the jack ends to drop it from line (headphone) level back to guitar level so not to blow out the Marshall inputs (sounded great BTW but very compressed (as I'm sure the GMA is)).  You could also plug it directly into a power amp (inputs) and run some speaker cabs off that.  One thing you'll find progressing down this path (amping up the GMA) is, the sound is very processed and compressed and will struggle to cut above any other instrument (if your jamming) without being too loud. I.e. they have very little dynamics.