Side Quest - Small Amp Upgrade

[Sundayjumper]

To avoid getting on and doing any real work on the car, I'm planning other more fun jobs instead. Today I got a great deal on a used Audison AP8.9 bit amplifier.



https://www.elettromedia.com/press_u...review1734.pdf

It's a tiny little thing as far as amps go, about the size of a chunky paperback, and not even very powerful, but it is hugely flexible with totally independent filters & EQ on each channel plus the mono pre-out (8.9 = eight channels of amplification, nine channels of DSP)



I used an AP4.9 in a previous F10 with the very very basic audio driven straight from the iDrive and it fitted *perfectly* in the top of the glovebox where the DVD changer would otherwise go. My current car has the marginally better "advanced" system so this one will go in the boot as a direct replacement for the factory amp.

It was cheap because it didn't come with any connectors. They're just Molex though. Aliexpress is great for this kind of thing 😎

Input - 16-way Micro-fit (3.0mm pitch): https://www.aliexpress.com/item/1005005499846429.html

Output - 16-way Mini-fit (4.2mm pitch): https://www.aliexpress.com/item/1005005894521227.html

And to patch it into the BMW loom, the connector to replicate the factory amp: https://www.aliexpress.com/item/1005007352513506.html

It'll all be here in a week or so and it should be pretty easy to put together a little custom loom for a neat & totally reversible upgrade 👍

[Sundayjumper]

Connectors have arrived. The pins are tiny 🤣 My poor old eyes are going to struggle a bit with this.

(the 4-way & 6-way connectors are to go with AP4.9 if I need it in future, for speaker out & DSP out respectively)

[Sundayjumper]

Done, I think, not tested it in the car yet, but bloody hell that was a faff. So fiddly. I wanted to use thicker cable but the BMW connector just doesn’t have space.

Pin Description
1 Not used
2 Not used
3 Bass front left -ve
4 Bass front left +ve
5 Power +12V
6 Not used
7 Not used
8 Input rear right +ve
9 Input front right +ve
10 Remote on
11 Front right +ve
12 Front right -ve
13 Rear right +ve
14 Not used
15 Not used
16 Input rear right -ve
17 Input front right -ve
18 K-CAN Bus-Signal High
19 K-CAN Bus-Signal Low
20 Not used
21 Rear right -ve
22 Bass front right -ve
23 Bass front right +ve
24 Not used
25 Not used
26 Ground 0V
27 Not used
28 Not used
29 Input rear left -ve
30 Input front left -ve
31 Rear left +ve
32 Rear left -ve
33 Front left +ve
34 Front left -ve
35 Not used
36 Not used
37 Input rear left +ve
38 Input front left +ve
39 Centre +ve
40 Centre -ve
41 Not used
42 Not used

The colour coding I used is shown below.