LS-671 with Blue Tooth receiver (help)

[madcroc1]

What I'm trying to do is install a Belkin Blue Tooth receiver inside one of my LS-671 speakers.
After reading the pin out on radio nerds, I figured it would be easy. There's lots of space inside the case so I figured if I can hook it up and put the receiver completely hidden inside the case so we could use the speaker as a powered blue tooth speaker.

I hooked up the blue tooth output directly to the speaker via pins E & F on J1 and it actually drives the speaker quite well albeit without volume control. I really want the signal amplified and I want to use the volume control and the power switch.



According to the radio nerds diagram I did the following:
I hooked 24v + to pins C&B on J1
I hooked 24V - to pin A on J1
I hooked signal TIP from the blue tooth receiver to pin K on J1
I hooked up Signal ground from Blue Tooth receiver to pin S on J1

The first time I hooked it up all seemed to work. The audio did boost well and then it stopped after about 20 seconds..

I suspect its the output signal from the Blue Tooth receiver is not high enough but I wanted to check with any radio pros here that may have an idea. The signal from the blue tooth receiver is only measuring from 5 to 9 volts but since the speaker has an amplifier in it, I figured that it would amplify any high impedance signal regardless of the input level. The radionerds schematic shows to hook up the audio ground to pin S on J1. I noticed that when the speaker is powered up (the light works), with the volume on MAX, I can hear music really faintly the signal in the background, kind of like its on a different line or something. I also noticed that when I remove the audio ground nothing happens.

I checked the speaker out by replacing them with several others and they all seem to do the same thing so I know its not the speaker, nor the receiver. I don't think there is anything actually failing, the signal is just not amplifying.

When I moved the audio ground to pin E on J1 (just to try it), I noticed that I get an amplified signal but not correctly as the volume control seems to exponentially increase the volume and it makes the volume control un-usable. I don't understand why I get over amplification when I hook the audio ground to the speaker (-).

Let me know if anyone has any ideas... Below is the radio nerds link on the LS-671

http://www.radionerds.com/index.php/LS-671/VRC

 

[madcroc1]

One thing I wanted to add is that I built a regulator circuit to power the Blue Tooth Receiver from the 24V supply.
The receiver uses +5v DC. I am adding a small circuit with a 7805 which will regulate the 24V to 5V. The heat will dissipate into the back of the speaker which is an excellent heat sink..

 

[mm58]

Also make sure the volume knob is pulled OUT to enable the speaker.

 

[T. Highway]

madcroc1,

Did you ever get this to work properly? I just got my LS-671 a couple of days ago and had wanted to do the same thing.

Bert

 

[madcroc1]

madcroc1,

Did you ever get this to work properly? I just got my LS-671 a couple of days ago and had wanted to do the same thing.

Bert

No. I just bought a few of them and I striped the board out then Picked up a blue tooth speakers from target. I replaced the circuit board and speaker with the one I got from target. So it a real blue tooth speaker with a battery inside. So none of the standard controls work but at least I have a military speaker.


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