View Full Version : Mobile Authority "Rockbox" m103a

10-06-2004, 12:32 PM
Amplifier by Mobile Authorty, an Anaba company

Rockbox m103a
2 channel 100 watt amplifier
2 x 25w RMS
2 x 50w MAX

Dimensions: 4" x 1.5" x 2.5"
Polished aluminum heatsink
Soft start circuitry
Thermal + Short circuit protection
Gold plated RCA inputs
High + Low level inputs
4 ohm stable
Gain control
150hz hi/low pass filter
Fuse size: 5 amp

Now the actual review..

Looks: 5/5
It's all polished, sleek, very nicely made. I was able to impress 3 people before I even got it home! It's small enough to fit in a moderately sized pocket, so finding a spot to mount it is nothing.

Appeal: 4/5
It's a heavy sucker, I can assume there's a lot of heatsink in it. It uses the same kind of wiring as you'd find on the high input of most amps for power, output, and high input. All in all it seemed pretty rugged, lots of screws and metal. My only complain is the gain knob comes off easy and is hard to turn.

Price: 5/5
I paid $40 for it, you can find them as low as $25 online. You won't find an amp cheaper than that.

Functionality: 1/5 in car - 5/5 in house
The real test is whether it can do what it needs to. So, I tested it.

• I turned off all speakers in my car except the front two. Then, I ran the left channel through my HU, and the right channel through the amp with high input. Both the amp's power and the HU's power were from the same hot/ground wires. I ran volume from 15/50 to 40/50, my tolerances for listening to music. The head unit outperformed the amplifier by a small, but noticable level.

• When put against my Jensen JXP 460 amp, results were similar. From the exact same power source, to the exact same speakers, at 100% gain, this amp will do the same as the JXP 460 at 40%-45% gain. This is NOT as good as you think.

• I also tested this amp against my busted Legacy LA120 240w amp. Th Legacy has been fried, only 1 channel works, it's filled with static, and probably lost a lot of power when I killed it. Similar conditions- I used my computer PSU to power them both. The Rockbox outperformed the Legacy amp by a league!

•This is a GREAT indoor amplifier.
While it's in no way powerful enough to drive car speakers in a car, driving speakers in a room is a different story. I wish I had pics. I hooked it up to computer! A standard 12v 18amp for a HD or CD drive out will do this amp nicely. Hooked up to 2 roadmaster 6.5" and horn tweeters, it sounds great, and it VERY loud on my Sound Blaster Live! 5.1 system. My computer is powering the amp, and providing the music to play with Winamp!

In conclusion:
It's nice looking amp, but it just won't outdo any moderate HU. Avoid unless you know how to rig it up in your room, because it's, ironically, a great home reciever.

(constant editing to add cosmetic appeal)

12-04-2004, 05:51 PM
UPDATE: As value added, this amp is bridgable / 3 way capable as an added bonus.
I'm also giving it more credit for it's durability. I dropped it twice, working on my room's placement, about a 3 foot drop from my hand to the hard oak surface of my desk / dresser. Didn't phase it a bit. It's a hardy little sucker. At the lowest possible gain, it never gets hot enough to keep you from picking it up and holding it. (Lower gains produce more heat, read into it)

It's still worth the money I spent on it.