Bluetooth Transmitter.

Yes, I imagine that most decent Bluetooth transmitters will just need an analogue line level output, in which case take signal from the tape out of your NAC72 via an appropriate interconnect to the transmitting device.

I doubt bluetooth has the range even if it were possible

Not really. Bluetooth is designed for close proximity and is very limited power and therefore limited  range.. so unless you have a very small garden, it is unlikely to be successful. For your need you are better off using Wifi and using a portable streamer speaker such as the Naim Qb if you have mains, or some of the battery powered alternatives.

if you really wanted to use your NAC output.. you would need a solution that can take an analogue input (say from your tape outs from your NAC) and stream via Wifi. Sonos have such a system, but you will need to use their speakers.

Thanks guys that’s been really helpful, I’ll let you now how it goes. As for range it’s just inside its limit.

Cheers.

When I looked up bluetooth transmitters  I saw that some claim a range of 50m or more.  However, I would be cautious about this and ensure that you are well within such a maximum range.  My experience with Bluetooth for audio has not been great, with lots of dropouts and futzing when using with a range over a few metres...

Richard Dane posted:

When I looked up bluetooth transmitters  I saw that some claim a range of 50m or more.  However, I would be cautious about this and ensure that you are well within such a maximum range.  My experience with Bluetooth for audio has not been great, with lots of dropouts and futzing when using with a range over a few metres...

50m!? Maybe some recent BT implementations have improved, but my experience is that 5m is pushing the limits, and certainly has to be within the same room. 

I agree with Chris,  OK maybe a bit better than 5m but for sure is better when both devises are in the same room.   Its OK for feeding MP3 from tablet to a potable speaker,  outside that,  best forget it.   

Ok to qualify my point further, I need to be more precise. Bluetooth comes in 4 classes, and each class has different power and range.

Class 1.     100mW.     Up to 100m

Class 2.      2.5mW.      Up to 10m

Class 3.      1mW.         Up to 1m

Class 4.       0.5mW.     Up to 50cm

Now most consumer devices for standalone devices that are not designed around the person (like BT headphones) are class 2,and will operate up to around 10m

Now BT Class 4, albeit rare in consumer space in my experience willhave the range similar to that of one of the older Wifi protocols such as 802.11b. Remember both the sender and the receiver will need the same class capability for reliable commas.

Bluetooth itself is a  series of wlan  protocols of different versions. Bluetooth 2.0 + EDR (not to be confused with Class2)  has a theoretical maximum data throughput of 2.1Mbps. Now although uncompressed CD quality PCM is about 1.4 Mbps, and with overheads could theoretically be carried, typically Bluetooth uses different lossy compression audio codecs to carry the audio such as aptX, ATRAC, AAC, MP2 and MP3

I suppose I should have looked into this more carefully as I bought a Bluetooth transmitter recently in order to try out some Nuraphone headphones. They appear to be no good for classical music as when the volume level drops too low the transmitter switches off to conserve power. 

Have a look at the TaoTronics range on the river I use one to send sound from my UnitiQute 2 in the kitchen to the shed and into a Audio Pro Addon T10. It's about 12 meters from the Tao on the Kitchen windowsill to the AP on the shed windowsill the is a direct line of sight. APTX is a step up in sound quality over standard Bt.

Remember BlueTooth categories and it’s supported audio protocol codecs are different things... 

The most basic codec, but mandatarory for A2DP enabled devices is SBC (low complexity sub band) that comes in at  320kbps. It’s not a particularly great lossy codec but widely adopted.

The next up is aptX, it’s also lossy, and maxes out at 352kbps,  but supports upto lossy 48kHz 16 bit LPCM, or the HD aptX at 576 kbps supporting lossy 48kHz 24 bit LPCM. aptX is a more advanced lossy codec and generally is considered significantly enhanced over SBC.

The generally  accepted next best codec is AAC, and on Bluetooth that can be provided upto 250kbps.. and proves the quality of a regular AAC at that encoding rate.

The next one up is the proprietary Sony LDAC that provides lossy PCM upto 96kHz at 24 bit at a maximum of 990kbps.. but not much equipment supports this and won’t work with Apple.