Audio Technica's turntables with Bluetooth functionality, like the AT-LP60XBT and AT-LP120XBT-USB, offer both a wired analogue output connection as well as a wireless Bluetooth transmitter to connect to Bluetooth headphones or speakers. Although it is possible to use both of the outputs at the same time, it may not be a good idea. Here's why.
While Bluetooth is a convenient feature, the audio sent over a Bluetooth signal is compressed. Thus, it will have a different sound signature than that of an analogue wired connection. There are many different Bluetooth codecs, which are algorithms that compress the signal differently. Even codecs that produce a higher resolution audio signal generate a different sound than a wired connection. Some people may prefer one codec over another.
Bluetooth signals also have an inherent latency (or delay). Once the audio is picked up by the cartridge riding through the groove on the record, the audio is passed through the turntable’s circuits to the outputs. The analogue output signal will arrive sooner to the speakers than the wireless signal that’s sent to the Bluetooth speaker. The Bluetooth audio passes through an A/D (analogue to digital) converter on its way to the Bluetooth transmitting components. It passes through the air over an RF signal, which is received by the Bluetooth receiving device. The audio then passes through a D/A (digital to analogue) converter before being sent to the speaker driver. The extra time taken to convert the signal and transmit it via RF can add between 30 to 300 milliseconds of delay, meaning the audio coming from the analogue speaker will be playing fractionally before the Bluetooth speaker.
While some people have used both outputs at the same time, it may be advantageous to use different outputs for different scenarios. For example, you may wish to use a wired speaker connection when listening near the turntable, but use a wireless Bluetooth speaker when listening in a nearby room.
The AT-LP120XBT-USB also has a digital USB output to connect to computers. This output is also active at the same time as the others, but like Bluetooth it has its own time discrepancy due to latency. The USB output's primary function is to transfer audio to a computer so you can digitise your vinyl for listening on other devices. Again, rather than considering using it at the same time as the other outputs, you might question what benefit it would add.
If you have additional questions about the audio connections on your turntable, please contact us.