By now, many of you have probably seen the MP3 FM Modulators coming out of China and Hong Kong. These units plug right into your car's cigarette lighter and broadcast your MP3's on the FM radio band. You just tune your car stereo to the same frequency as the Modulator and now your MP3's play right through your car stereo. Most of these units will accept USB Flash drives and SD Cards. However, the similarities between these various units ends there.

Card Size

The MP3 FM Modulators do not all accept the same size memory accessories (USB Drive, SD Card). All the Modulators will accept Flash drives and/or SD cards up to 2GB (2GB will store approximately 400 songs). Some Modulators will accept Flash drives up to 16GB. Research this feature carefully before making your purchase or you may end up buying more memory than you really wanted to.

Memory Function

Most of the current models of MP3 FM Modulators, have a memory function. The Player will remember your settings, and the current song playing when you unplug it. Many of the older versions DO NOT have a memory function. This may not seem like an important function, but believe me it can be very frustrating to find your spot in a 400 song playlist.

Playlist Functions

Most MP3 FM Modulators have several different playlist functions like play songs in alphabetical order, play songs in time stamp order, play songs only in a certain folder, or play songs in random order. Not all modulators have all these functions, and its usually very difficult to tell from most manufacturers and retailers websites what specific playlist functions are supported. What I tend to look for, is the random play function. This seems to be the playlist function that is most frequently left out and is also most frequently mentioned when the player has it. when I find a player that has the random play function it usually (not always!) has most of the other playlist functions.

Transmitter Power

I've seen MP3 FM Modulators come with either a 12V or 24V transmitter. The 12V transmitter is the most common. These units have a range of about 5-10 feet maximum. If your radio is any further away, all you'll hear is static. This is perfectly OK, if your primary use is in the car. It's pretty rare that your cigarette lighter socket is more than 5 feet from your car stereo. The 24V models are not as common and tend to be a little higher in price. These higher powered units tend to have a range of 50-100 feet. This makes these 24V units great for home use. I plug mine into a cigarette lighter wall socket adapter and I can pick up my music from any radio in the house. Just think, no CD's to move or find and no fiddling with the tuner. You are your own radio station. You have the same music available to every radio in your home all at the same time. Move from room to room without ever missing a beat. Now don't get input power confused with transmitter power. Almost all MP3 FM Modulators will accept 12-24V input power. That is not the same as transmitter power.

In Conclusion

Other than the variety of styles, shapes, and colors these units are available in, this article encompasses the major technical differences in this line of products. Shop well and shop wise. While returning an item to China or Hong Kong is not impossible, it is incredibly inconvenient, and time intensive. There are now many US Sellers importing these players. While their price tends to be higher, shipping is much faster, and returns much easier.