How to reduce Hi-Fi bluetooth transmitter noise, when listening using bluetooth headsets or speakers

[guerney]

My Sennheiser RF wireless headphones are ace, but I like using neckband "Sports" bluetooth headphones sometimes, when pottering aound doing physically intensive things, because they don't fall off. Also, on-ear headphones get sweaty. So I thought I'd try listening to my HiFi via bluetooth, bought a couple of these cheapo transmitters, but they are noisy when connected to a USB power supply:

https://www.ebay.co.uk/itm/315356226866

https://www.ebay.co.uk/itm/364921032300

The good news is, they pair fine. Sound quality is just about bearable with tweaks along the line, but hardly audiophile, but £9 Asda bluetooth neckband earbuds (on sale for £4) can't hold a candle to my seriously wonderfully awesome Sennheiser HD600 of course, but now I know these pair with generic transmitters, I can buy better bluetooth earbuds.

Sennheiser HD 600

Headphones Dynamic, Open, Circumaural, Impedance: 300 Ohm, Sound pressure level: 97 dB, Frequency range: 12 - 39,000 Hz, Two-sided cable routing, 3 m Cable with 3.5 mm jack connection, Weight without cable: 253 g, Weight with cable: 309 g, Includes...

www.thomann.co.uk

...but there's godawful interference noise from somewhere, when not operating on internal battery... until I bunged these onto the USB power cable:

https://www.amazon.co.uk/dp/B0DX6LVTFR

The seller sent only four instead of five, so I got a 25% refund.

Er... that's it, that is all.

 

[guerney]

Oh and the two devices above automatically pair with each other, to transform your better headphones, or whatever else (other hifi, bluetooth speaker) you've plugged in, to bluetooth - simply set one to transmit and the other to receive.

The batteries in cheap stuff like this die a quick death, but when that happens they're easy to replace, or they work on external power (hence the importance of low noise) if you rip the batteries out.

That really is all.

 

[guerney]

As mentioned often, there's rather a lot of latency when connecting HiFi via bluetooth transmitter to bluetooth headphones, big delay with Asda neckband "Sports" earbuds. However, happily latency is almost negligible when the transmitter is connected to the receiver to Sennheiser HD600. Range is <10M, if there are no obstacles especially. Overall, not a completely awful solution if you wanted to use your posh headphones or other non-bluetooth enabled equipment with newfangled bluetoothed gear, or wanted to make old gear wireless cheaply, while trading away best quality. Headphone out of the receiver can be line-in to something else.