How to make a source unit for a musical car horn?

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For right now I can use my car stereo head unit as the source; just burn the sound clip to a CD, and it goes through the amplifier and to the horn speakers behind the grille. I would like to have a small dedicated source unit for it though, i.e., something that will simply play a sound clip by pressing a button.

I know there are small devices out there that can do some of what I need, such as this device, but I need more functionality.

I need/want:

1. Preamp outputs (using RCA jacks preferably)
2. Volume control
3. Ability to be powered from car voltage (12.6 to 14.4 VDC)
4. Ability to play 16-bit, 44.1 kHz, 2-channel PCM (.WAV) sound clips loaded directly from a PC to its memory (only needs to be able to play one; I don't need nor want selectability among multiple sound clips).

Does anyone know if there are any off-the-shelf devices out there that can do this or can be hacked to do this, or how I would go about building one?
 
Look up hacking the "that's easy" button. and amplifier and PA speaker.

Or use a raspberry pi as an audio source. and amplifier and PA speaker.

Or a really cheap mp3 player. and amplifier and PA speaker.

🙂
 
Look up hacking the "that's easy" button. and amplifier and PA speaker.

Or use a raspberry pi as an audio source. and amplifier and PA speaker.

Or a really cheap mp3 player. and amplifier and PA speaker.

🙂

I just watched a video about hacking the Staples "Easy" Button, but the end result of that is no different than the device I linked to in my OP, i.e., no preamp outputs, no volume control, runs off 9 VDC rather than car voltage, and no direct file transfer (i.e., you have to "record" the sound clip onto it, rather than simply transferring e.g. "soundclip.wav" to it).

I don't think that any cheap MP3 players have true preamp outputs like you'd use with a car audio amplifier; they have amplified outputs to power the speakers in head phones. Plus, do any of them have "just push a button and it plays the only audio file on there" function? There are usually menus and stuff on those things which prevents such simple door bell / car horn / tape player type single-button-push functioning.

The Raspberry Pi looks interesting, but it is probably beyond my capabilities to make it work. I'm guessing you'd need custom software to get it to do what you want it to do, and I know nothing about computer programming.
 
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I don't think that any cheap MP3 players have true preamp outputs like you'd use with a car audio amplifier; they have amplified outputs to power the speakers in head phones.

They can drive low Z loads; it means that some current flows, being Vout determined maximally by Vs which may be 3V, so rail-to-rail peak minus losses of silicium junctions...let's say about 2 V, the norm for line level.
With the internal volume control of the device you can set Vout for any level needed. The difference between line level output and HP output is that the HP needs an extra stage - amplifier or current buffer !?!-
 
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