BEOTOOTH 5500 : A Datalink Bluetooth Receiver

[Caleb Dougherty]

Hi pilatomic,

I have a Beomaster 2400.  Would the Beotooth work with that?  If so, I’d be interested in purchasing the kit.

Sorry, I can’t find where to send a PM.

-Caleb

[pilatomic]

Hello,

Already 2 months went by since my last update here, and I have another firmware update available :

V1.5 fixes an issue where the Beotooth would mistake a datalink command for a Play command, and start playing when it should not (typically triggered on some Beosystem by switching from CD to Radio).

As usual, contact me in PM to obtain the new FW and update instructions !

[pilatomic]

The Beotooth is more targeted toward Datalink era B&O devices, those use a data bus through a DIN7 socket to plug into the Beomaster.

Your Beomaster is an earlier model, and doesn’t use the Datalink bus. The Beotooth would still work as an good audio source for it if fitted with a DIN5 connected instead of the DIN7.

I can’t seem to find the PM either on the new version of the forum, so if you’re interested nonetheless, just leave a comment on my website with your email address, and I’ll be in touch.

EDIT : I can’t seem to be able to post a link, is the forum really that broken ? 🙁

You’ll have to resort to lookup on a search engine “pila.fr Beotooth 5500”

For those who want the new FW version, maybe just do the same (ask as a comment on my website) until I find how to read / send PM.

[T.W.G]

Very interesting device and good work!

Does it support other codes than AAC? For example aptx?

[Caleb Dougherty]

Just received a Beotooth 5500 today.  I was able to modify the DIN7 by cutting the Datalink wire and then heating the two extra pins with a soldering iron and pulling them out once the plastic slightly melted.

Plugged into my Beomaster 2400 with S75 speakers (both just restored with new caps and other failed parts).  Sounds great!

So glad to be able to play something other than the radio 🙂

The sound quality seems crisp and clear.

Thanks @pilatomic!

Going to restore the turntable next…

[Madskp]

A little curious question. Would it be possible to change the TAPE command with the CD command for the Beotooth 5500?

One usecase I could seen for this is a computer using one Beotooth as speaker connection, and the other beotooth could the be used for connecting a phone

 

[T.W.G]

On Madskp said

A little curious question. Would it be possible to change the TAPE command with the CD command for the Beotooth 5500?

One usecase I could seen for this is a computer using one Beotooth as speaker connection, and the other beotooth could the be used for connecting a phone

 

That is a good suggestion. Maybe a small swich can be integrated which chooses to which command the Beotooth will react: Tape, Tape 2, N.Music, CD …

[pilatomic]

Hey, Sorry for the long delay answering, since the forum update I don’t get emails anymore when replies are added to the thread.

On T.W.G said

<p>Very interesting device and good work!</p>
<p>Does it support other codes than AAC? For example aptx?</p>

<br>

The Beotooth uses the Microchip BM83 Bluetooth module, which only support AAC and SBC.
I ad a look at AptX in the beginning of that project, but it is a Qualcomm proprietary technology, only available on Qualcomm Bluetooth modules,
and Qualcomm doesn’t give their SDK to everybody except, so no luck there.
AAC should deliver a similar quality to AptX (except on some phones where the AAC codec seems flawed, but that’s an issue with the phone manufacturer).

On Madskp said

<p>A little curious question. Would it be possible to change the TAPE command with the CD command for the Beotooth 5500?</p>
<p>One usecase I could seen for this is a computer using one Beotooth as speaker connection, and the other beotooth could the be used for connecting a phone</p>
<p> </p>

<br>

That’s an interesting idea, I had not thought about that (as I still listen to CDs on a regular basis).
On the back of my mind, swapping the control messages should be fairly easy, the status messages are a bit different though, but nothing impossible.
I’ll have a look at that when I have some free time.
(It could be added as a selection command through the USB Serial interface, that is already used to customise the Bluetooth name of the Beotooth).
There would be only 2 options here : Beogram or Beocord emulation (AFAIK Beogram CD and Beogram uses the same command set).
On a system with CD / PHONO / TAPE / TP2, CD and TAPE share one datalink bus, and PHONO and TP2 share another bus.

[Madskp]

On pilatomic said

Hey, Sorry for the long delay answering, since the forum update I don’t get emails anymore when replies are added to the thread.

You might have to re subscribe to the thread. Thats is the case for all threads I have subscribed to before the changes.

 

On Madskp said

A little curious question. Would it be possible to change the TAPE command with the CD command for the Beotooth 5500?</p>
<p>One usecase I could seen for this is a computer using one Beotooth as speaker connection, and the other beotooth could the be used for connecting a phone</p>
<p> </p>

<br>

That’s an interesting idea, I had not thought about that (as I still listen to CDs on a regular basis).
On the back of my mind, swapping the control messages should be fairly easy, the status messages are a bit different though, but nothing impossible.
I’ll have a look at that when I have some free time.
(It could be added as a selection command through the USB Serial interface, that is already used to customise the Bluetooth name of the Beotooth).

<p style=”text-align: left;”>Great to know it is possible no immediet need for me, but some other usecase might show up</p>

There would be only 2 options here : Beogram or Beocord emulation (AFAIK Beogram CD and Beogram uses the same command set).
On a system with CD / PHONO / TAPE / TP2, CD and TAPE share one datalink bus, and PHONO and TP2 share another bus.

That was also my understanding. The current TAPE function works both on the Tape and the Tape2 connection on my BM4500

 

[Caleb Dougherty]

Hi @pilatomic,

I’ve been enjoying my Beotooth for a little while now and have some minor feedback.

• I can’t “steal” the audio connection using another device while the first device is still connected.  I have to disconnect the first device before the second device will connect.  Would be a nice feature to have.
• If I power off the Bluetooth while my PC is connected, then enable BT again, it will connect to the Beotooth but not show an audio device.  I have to press the pair button on the Beotooth and reconnect to get an audio device to show in Windows 11.  Might be a Win11 problem, but it’s pretty consistent.
• The volume range seems to be non-exponential.  The bottom half of the range doesn’t seem to change the volume much and the audio cuts out completely at about 1/10 and below.  This is with an iPhone, by the way.

Not a big problem, but thought I’d just mention it.

[pilatomic]

Hi @kleb,

Thank you for your feedback !

• I have checked the documentation of the Bluetooth chipset I’m using, and it seems possible. I might look into that in the future.
• Hmm this one I haven’t seen, but I mostly use my Beotooths with an Android phone or a Linux PC. I’ll try to get my hands on a Window PC to check that !
• You’re right about that. In my mind, the Beotooth is meant to be used at a fixed volume level, with the volume controlled by the Beomaster. I’ll  try that, and see if I can make changes to the scale.

[pl212]

A quick link to some pictures of assembly:

https://www.flickr.com/photos/peterl/albums/72177720322347136

Despite my slightly dodgy soldering skills, everything works! The attention to detail on these kits is amazing, from the flush-mount LED, to the molding of the case itself, to the label, to the cable strain relief.  Highly recommended!

[Author]

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