A-MP016 MP3 Player

This page is about the first dirt-cheap MP3 player, the A-MP016.

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Overview

In June 2006, a particularly cheap MP3 player was spotted at some surplus outlets.

[photo] 


 

Sources

vendor part number description price
Marlin P. Jones #16520 MI MP3 PLAYER $4.95 [9/2006]
B. G. Micro #AUD1081 MP3 player $5.95 [9/2006] 

 

Battery Life

Halloween-L member Nitefin bought one of these players early and reported to the list on the battery life. Nitefin reported that when the battery ran out, "it did not drag or slow down it just shut off." 

 

Alternate Power

The battery can be replaced by a line-operated power supply.

If you go this way, you have to be very careful in regulating the voltage that it gets. Go for a nice, solid 1.5V. If you go higher, the player goes into USB mode.

The player looks at the voltage that it gets to determine what mode to operate in.

There are fixed positive voltage regulators out there:

Or you could use an adjustable regulator like the venerable old LM317: 

 

Software Drivers

In order to load MP3 tracks into the player, it is inserted into your computer's USB port. The player acts like a little disk drive. You can copy files to the player and back using standard operating system features.

The instructions for the player state that no special software or drivers are needed for Windows 2000, Windows ME, or Windows XP. I have used the A-MP016 MP3 player with Windows XP, and it works fine.

The unit does require special driver software for other operating systems.

Wolfstone reader David Harris kindly dropped me a note saying that he had found a Windows 98 driver that works with the A-MP016 MP3 player. He found it at http://www.phison.com/english/manager/uploads/technology/v125r000.exe Thanks, David!

Reader Rodolfo Seoane reports that this same driver also works with Windows 98SE (spanish edition). 

 

Operation

The controls are sparse: one LED for feedback; 3 buttons for operation.

The LED indicates several things, and the buttons also do several things:
function steps
turn on Press and hold ">\||" for 3 seconds. Player starts playing; will play all tracks in sequence; when it gets to the end it repeats, starting at the beginning.
turn off Press and hold ">\||" for 2 seconds.
pause Press ">\||" briefly. The light turns red.
resume Press ">\||" briefly again. Play resumes immediately.
next track Press ">>|" briefly.
previous track Press "|<<" briefly.
increase volume Press ">>|" for 2 seconds. Light turns red and blinks to indicate volume mode. Use ">>|" to increase, "|<<" to decrease.
decrease volume Press "|<<" for 2 seconds. Light turns red and blinks to indicate volume mode. Use ">>|" to increase, "|<<" to decrease.

You can also view the original instruction sheet. 

 

Sound Quality And Storage Capacity

Sound quality is standard for an MP3 player: not as good as a CD, but better than a tape or most canned sound chips.

You can trade off sound quality for playing time when you encode sound as MP3 by adjusting sample frequency and bit rate. See MP3.

So, how much sound could you get into this 16MB player?

As a random sample, I checked the file "avalanche.mp3" downloaded from the site of the artist Thea Gilmore (http://theagilmore.com).
title Avalanche, by Thea Gilmore
bit rate 64 kbit/s
playing time 4 min 21 sec
storage space 1.99MB

At that rate, you could record over half an hour of stereo in 16MB. 

 

Electrical Connections

The USB connector used in the MP3 player is wired like this:
[photo]
pin function
1 VBUS
2 DATA-
3 DATA+
4 Ground
shell shield
In normal USB operation, VBUS is 4.75-5.25 Volts.

The audio output is via 1/8" (3.5mm) stereo jack. The matching plug is wired like this:
[photo] 

 

Controlling With A Computer

There is a lot of interest in operating this MP3 player under the control of a computer or PROP-1 controller.

The basic idea is simple: set it up so that the controller "pushes the buttons" on the MP3 player.

To trigger the player from a controller, miniature relays always work. The relay contacts are placed in parallel with the mechanical switches on the player. Consider this the brute force method.

I have spoken to haunters who have tried other solutions, like stacks of diodes or a resistor to condition the Prop-1 output, and injecting that into the player. So far, nobody has reported getting this to work.

Personally, I'd like to try some sort of open-collector transistor switch. Failing that, a transmission gate (e.g. 4016 or 4066 quad bilateral switch). Here's a web site that describe the 4016 and how it can be used: http://www.doctronics.co.uk/4016.htm. Here are some related chip data sheets:
chip description data sheet
4016 quad bilateral switch http://www.fairchildsemi.com/ds/CD/CD4016BC.pdf
4066 improved quad bilateral switch; more linear; lower ON resistance http://www.fairchildsemi.com/ds/CD/CD4066BC.pdf
4051 analog multiplexer/demultiplexer (1-of-8 switch) http://www.fairchildsemi.com/ds/CD/CD4051BC.pdf

I have the players, but haven't tried computer control yet.

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