Or is it built into the in-dash deck?

I bet it has a amp. But, the ohm levels are weird so you cannot switch it out. If thats what you are thinking about doing. Hehe.

I think the standard system has a separate amp, but I would suggest you call MBUSA's 800 number and ask.

The people at the 800 number said the amp was built into the radio.

Maybe someone who has taken out the radio to put an Audio 10 in can answer. I doubt that the radio is the only power amp. The radio will get way to hot if the power amp is inside that small DIN sized package. The speaker impedences are on the low side from what we've heard on the board and that requires a higher current amp.

Just about every stock stereo system (excluding "premium" systems) has the amp built into the radio. They're called "high power" head units, although they usually are less than 50 wpc (they are usually 15 - 25 wpc). I think the low ohm speakers we've been reading about in various posts are referring to the Bose speakers. I know the service bulletin referred to by Vadim in another thread made reference only to a "Bose amp". Not to offend anyone, but I don't get anything out of looking at someone's new stereo that was installed by some pro shop. Show me what YOU have done


Jim

Most of the ratings of car stereo head units are grossly inflated as there is no regulation of how the spec is rated, it is unlikely that the built in amp is capable of driving the volume levels I've heard from the front speakers. The rear speakers sound like they are powered by the head unit's built in amp, not the fronts though. Like I said before, if someone has removed the radio they will know if it has speaker wires, its that easy. As far as the low impedances, any good aftermarket amp will drive a load two ohms and up. The reason for the low impedances is to increase the available wattage at lower power supply voltages (at the expense of higher current, half the impendance=twice the current) that are much easier to make in a car with ~13.8V to work with. Switching supplies can be problematic in a car audio system if required to create higher voltages due to the filtration and rf shielding needed. Anyone know what the fuse rating on the radio is? That will tell us if it is possible for the amp to be built-in.

The fuse on the back of the radio unit is 10Amp. The unit has 3 multi-prong connectors on the back side, along with 2 coax and one optical one.

In my case (Bose), the middle connector is missing (compared to the photo attached) - perhaps the one carrying the power amp outputs? It sure looks so judging by the wire gauge size.

vadim
how did you remove the head unit?
i have heard it is very simple, but i just don't know how to do it, and can it be done without a special mb tool?

Instructions for removing the radio are here... https://mbworld.org/forums/showthrea...=&postid=69570

Clint- Jim beat me to it if you like, I can email you some photos taken during head unit removal/installation by a few people from this board (myself included), that might help as well.