Before going into details about my project, I wanted to show you what is inside other audio recorders. a week ago, I bought a Zoom Q2HD and a Zoom Q3HD, both in bad condition (the Q2HD had pretty bad battery corrosion, whereas the Q3HD had a burned PCB…).
There are 3 pcbs inside a Zoom Q3HD :
- SD card slot + lens/sensor assembly
- logic board (cpu+ram+flash) and lcd
- I/O, audio CODEC and power supply (which has burned…)
The main chip here is an Ambarella A5s-CO-RH SoC. it features an ARM core (clocked at 528 Mhz), and all the bells and whistle you'd need to make a video camera (h264 encoder, i2s interface, video dsp). Next to the Ambarella chip, there is 1gbit of hynix DDR2 ram. On the other side of the logic board you can see 1gbit of st nand. Nice hardware here.
On the i/o board, we have a Wolfson WM8750 codec chip. this chip does the analog/digital conversions. I don't know which protocol is used for audio data in the Q3HD (the WM8750 handles i2s, left-justified and "dsp mode") as I can't boot it properly.
On the same board we'll also see a couple of JRC NJM2100 op-amps. I guess they are used to amplify the microphone capsules.