IDK if this has already been considered, but i've been thinking about the n900's internal dac, and how to best interface the audio out of my n900 to an external dac amplifier (ddx320).

And we all know about the woes of usb dac out, at least natively with the media player application in hildon.

But one thing i haven't seen discussed, is using a high quality bluetooth reciever module, with a decent dac unit onboard, to decode to analog as close to the amplifier/headphones as possible.

Something like this-

http://www.kcwirefree.com/kc6112.html

With the idea being, internally mounting the module, or at least the circuit if you need an external antenna to get the best possible signal reception from the n900.

I asked one of their rep's about digital output from that module, and he said pcm, is possible coming from an a2dp source like the n900. Technically theres no a/d conversion there, if its puttting out pcm, and yeah its 16bit 48khz max, but still, that significantly reduces, or offers the possibility of reducing, analog noise/interference in analog audio runs.

My plan, would be to just have my n900 pretty close to the reciever module, and use the amp's dac to decode the pcm output from the above module. At least it an alternative to the internal dac, and analog wire runs to amps/headphones.

Then theres the possibility of a decent usb BT device, that is better than the stock BT transmitter/hardware on the n900. If thats a feasability, perhaps decent quality high power BT modules, one recieving and kicking out digital pcm to an external dac/or digital amplifier in my case, one transmitting with better hardware/signal power/quality, by going through the usb port to a BT module of better quality than the internal n900 hardware.

Am i right in assuming the dac isn't involved in BT a2dp out on the n900? And if you used a bt reciever that could kick out pcm, you could have an all digtial link to your external dac, or use the dac onboard the kc6112, assuming its of better quality than the n900's internal unit.

Granted, this is all wireless, which presents its own problems, and i haven't really looked into digital/digital transcoding factors involved in such an implementation, but perhaps someone can chime in here and offer some information.

Like if going from digtial signal internally in the n900 to either its stock bt transmitter, or a usb bt module, and how that signal is transcoded for BT transmission, is going to be a bottleneck, or problem as far as making a digital link over BT a2dp no better or worse as far as how that digital signal gets fiddled with on its way to your external dac accepting a pcm input from a device like the kc6112.

Just some things on my mind as of late, right now i'm getting a cheap adc and just piping out analog from the 3.5mm, once i get a replacement jack of course, but perhaps bluetooth might be a better option, if done correctly.

Any thoughts?

try it

i use BT A2DP wth my Sony car stereo that supports A2DP. not bad. I also generally hook my laptop to an amplifier in same manner. cant use a BT mouse very well cause of that though, but no big issue for me. as long as there is little wear n tear n its convenient.

not the thing to go for if u want really high quality audio.

kh

Install fuppes or miniDLNA and use the N900 as Media-Server. That will give the best sounding results.