DIY Micro PCB Headphone Amplifier (Part 2)

This is a continuation of a DIY Mini (or micro) headphone amplifier. I have already talked about it in the first part and even made a working prototype. But the protopine was big in size, so I have decided to order a PCB and make it as small as possible.

Other post parts

The PCBs made by PCBWay

Yet again I have got the boards from PCBWay which also sponsored the boards which are showed in this post. Nonetheless, their PCB manufacturing pricing is good and they manufacture the board quickly and deliver them safely.

PCBway packaging box

If you want to get more information about how to order the boards by yourself, I have already covered it in one of my blog post here.

PCBWay good pcb packaging

The Boards

These boards are 18 mm x 6 mm in size. Their thickness is 0.8 mm. So, as the this post’s title suggests – the boards are tiny!

DIY Tiny Headphone Amp PCB measurements metric

On the board there are place for two main circuits. The first one is operational amplifier based on INA1620. Its gain is fixed and set to 2. As the previous testing shows, gain of 2 is optimal for both worlds – low and high impedance headphones. Well, it might be a bit too much for low impedance ones – the distortion can be heard, but you can always just turn down the volume a bit :).

DIY Tiny Headphone Amp PCB measurements imperial

The second circuit, which is populated on the board, is power delivery. It is based on a TPS65135 IC. Its main purpose to make dual voltage for the op-amp from a single voltage (5V) supply.

As you can see in a photo below, the electronics parts goes on both PCB sides:

Diy Tiny Headphone Amplifier Ina1620 pcb top bottom

Again, the boards are so tiny that there were not enough space on the front side to fit component markings. Note, that as the boards are so small, the PCBs in the photo above might look worse than they are in reality – all markings are perfectly visible and there are no visible quality issues.

Finally, the main idea of such small PCB was to make an adaptor-like USB-C device. On one end it will have a USB-C DAC which will then connect to this amplifier circuit and from it the signal will go to a 3.5mm audio jack.

Headphone Amplifier PCBs made by PCBWay

Further Steps

Next step is to order some components which I still don’t have, somehow solder the PCB and test how it works. Final step will include manufacturing some kind of enclosure for this device.

Subscribe to a newsletter!

Was this page helpful?