The reverse to what is expected

[scassani]

I want to connect a Sennheiser Bluetooth Audio Transmitter to a Yamaha A-S2100 Integrated Amplifier.  The transmitter accepts input through a 3.5mm plug.  The amp has a headphone jack that could be adapted to receive a 3.5 mm plug.  Sennheiser anticipates the transmitter will be connected in this way.

 

My need would be met better by connecting the transmitter to the twin speaker outputs on the amp.  In this way I could toggle between Speakers 1 and 2, with 2 going to the transmitter.  The amp shuts off the signal to the speakers automatically when a plug is in the phone jack.  The automatic shut-off requires that I unplug from the phone jack on the amp every time the Bluetooth transmitter is not in use.  I cannot simply leave a plug in the phone jack and switch the transmitter off.  I can avoid wear on the plug and amp by switching from Speaker 1 (ambient sound) to Speaker 2 (Bluetooth transmitted to headphones).

 

I need to connect the dual 6.35 mm outputs labeled "Speaker 2" on the amp to the analog 3.5 mm single input accepted by the Sennheiser.  Connecting the devices this way seems idiosyncratic; every cable I've found works in the opposite direction.  The signal from an I Phone or like device enters the 3.5 mm end and the cable splits the signal in two for output to a speaker.  I want the amplified signal to run from Speaker 2 (left and right outputs) to a single device, the Sennheiser Transmitter.

 

My need cannot be met simply by running the signal in the direction that is opposite to the design of the cable.  The splitter function (one signal to two) does not work in reverse.

Any thoughts?    

[scassani]

Sennheiser confirmed that the headphone jack is the sole means of connecting an amp as old as Yamaha's A-S2100 with their Bluetooth Transmitter. 

[jcbenten]

Is the Sennheiser BT signal proprietary?  Can't you get something like this?:https://www.amazon.com/Bluetooth-Receiver-Wireless-NFC-Enabled-Streaming/dp/B07TK8ZKQT/ref=sr_1_1_sspa?dchild=1&keywords=bluetooth+receiver&qid=1616173983&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyMzlRVFg0QTk0VUMyJmVuY3J5cHRlZElkPUEwMTQ2NDI0RUhCNzBVRzg0Q1Y4JmVuY3J5cHRlZEFkSWQ9QTA2OTkzMTc3TEtCUE5DRFBNQ0Emd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

Or am I misunderstanding?

 

[scassani]

Jcbenton refers me to a Esinkin Bluetooth Receiver.  Connecting the Esinkin would enable my Yamaha A-S2100 to receive a Bluetooth signal from an IPhone.  The capability I'm looking to achieve has the signal originate in the aged amplifier.  The amplified output becomes the source of the signal the Sennheiser transmits to Bluetooth receptive headphones.  Think of the direction I wish the signal to follow as being identical to what would be achieved by linking the old amp and modern headphones by way of a cable.  

 

I'm trying to make the old stereo sound system talk Bluetooth to up-to-date headphones.

[jcbenten]

Sorry...I am going backwards.  3.5mm jack is easy.  Going from the B-Speakers ... hmmm...seems to me that the signals are incompatible.  Sorry I do not know.

[One and a half]

The speaker output is way too powerful to use and will overload the bluetooth transmitter. It's only good for 'line level' signals. If the amp has a REC out, use that instead with the appropriate adapters. Or something like the Erskine Unit.

[scassani]

Thanks One and a half.  In my communication with Sennheiser I spoke directly to using the headphone jack.  The technician affirmed that the signal is within the prescribed maximum load (5 DB), provided I follow the steps I outline in a previous post.

 

The Sennheiser transmitter and the B&O headphones do not speak the same Bluetooth 'dialect.'   The transmitter shows alternating blue and red lights, indicating the unit is searching for a response.  The headphones are on and set to acknowledge a compatible signal.  This state of call with no response continues until the headphones detect the maximum period of inactivity and switch off automatically.  The headphones are configured in the way that routinely succeeds in the phones shaking hands with a Kindle.  No such luck with the Sennheiser.

 

I've concluded that the sole means available to me is to bypass the current technology.  A cable works.