21st Century Integrated Amp

New topic on an integrated amp being developed and rumoured in the "Bluetooth Private Members" topic.

It looks like anything without Bluetooth won't get a look-in for a 21st century integrated amp, and if it doesn't do aptX it won't be "cool".

Therefore the job isn't worth starting until the Bluetooth connectivity is developed, and that is what we've been doing for the last few weeks, on and off.

Today we got connectivity to be able to output SPDIF from Bluetooth sources, namely Samsung S4's, a Samsung S4 Note, and a Huawei/Kestrel.

The "Note" sent FLAC via aptX, the S4's sent OGG and MP3 via aptX and the Huawei/Kestrel sent MP3 via SBC, all forms of A2DP.

Pairing was straight forward only requiring each phone to search for the Bluetooth "sink" device, and that device is pictured below...

Don't try this at home!!!



The bit hung down with the USB cable attached is the programming unit, which is also acting as power supply to the Bluetooth module. Once programmed, the module simply worked on its own as Bluetooth to SPDIF converter, only requiring power - great!

Normally you'd get to this point by using a development board or at least a break out board, but that's a little too easy - and a trifle expensive just to find out if it works. Why shouldn't it work? Well, two weeks ago we tried a different module on its own development board kit, only to find it to be a complete "abortion". That cost well over £100 to end up with nothing.

This time we thought, "what the heck", we'll just string on some bits of wire - not as easy as we'd have liked, as this one has a really fine surface mount connection pitch (only 0.8 of a millimeter). I managed to wreck one of its LED indicator terminals, but, we thought "do we really need indicators?" - the phones will tell us if they've paired anyway.

I don't think there will be many finding this module easy to get along with. Nothing wrong with the module as such, but it's data is way out of order, and has plenty of mistakes which we duly discovered.

Anyway, it works. Next up is to see if we can actually solder them to a board... by hand!!!

That is definitely exciting Graham! I'm looking forward to updates during the development of this amp, and especially the finished product!

ServerBaboon wrote: I assume its a cost issue but is there not a socket that will fit this device? surely that would be easier with less chance of bricking a device.

Bricking the device and bricking the PCB!

Cost issue? At £30 each per module there's no danger of that.

Unfortunately there is no such socket available - or I'd be using it.

This has the potential to be a really exciting new product! The best of all GSP product lines in a svelt enclosure - what's not to like?