Open Source Comfortable Headsets

While thinking about things to occupy my time over Christmas I realised I had almost all the pieces to go from a pc headset to a bluetooth headset.

I have a large USB powerbank I got for free at a convention and with the addition of an XS-3868 module I will be able to use the headset via bluetooth on my phone or on my pc.

XS-3868 Bluetooth module

If the module arrives in time I will assemble everything tomorrow and take some pictures.

There is a great guide to one hackers use of the XS-3868 curiousmuch XS-3868 build log

I started this project back in march but stopped due to various time demands. I was finishing my PhD and doing all sorts of other things.

I remember testing the headphones with the pre-amp on my pc using a cheap usb sound card. I remember it worked but the cheap braided cable didn't solder nicely and I took it apart in preparation for packaging everything inside a box.

Velleman Kit Instructions

I remember soldering the kit together and making sure it worked but seemingly forgot that it was a pre-amp for the microphone(it's dynamic).

I'm going to get some better wire and reassemble everything for another test prior to de-soldering the sockets from the USB hub i've bought.

In the interim i'll use a 12v bench supply to power the pre-amp but for the final device I'm looking at using a boost converter to go form the 5v usb rail to the 12v required by the pre-amp.

Probably something like this cheap Chinese boost converter

Cheap as chips not as nourishing?

Hopefully i'll be able to nip into a lab somewhere in the university and do an assessment of the noise from the boost converter.

The USB hub arrives and claims to be USB 3.0 P/N 30420

It has a micro USB port for an external power supply.

I tested it with my PC it and works fine.

A little gentle application of a spudger and the case has yielded the board.

The plan is to remove the mic and headphone sockets and wire the circuitry i've created to adapt pc level to NATO headset compatible levels in between this board and my Type 626 socket. That way to use the headphones they just have to be plugged into this box.

The Audio chip appears to be HS-100B

HS-100B datasheet

The USB chip appears to be GL3520

GL3520 Datasheet

To bypass messing around with a cheaper sound card which plugs into USB but can't fit both jacks at the same time I decided to buy a more expensive USB hub with sound card and crack it open. This will allow me to connect the circuitry directly and also take power form the hub to bias the mic and power the pre-amp.

I chose a reasonably cheap UGreen one from amazon.

UGreen USB 2.0 hub with integrated sound card

My pre-amp was just a kit from maplin.