The Sony A6500 is a fantastic camera. It has an extremely high-resolution EVF, great ergonomics, and excellent 4K video quality with full pixel readout. However, it does have one glaring flaw: the lack of clean headphone audio out. If you're used to recording for other people or just want better audio monitoring, this can be a huge bummer. Luckily for us all (and especially those who work in radio), there's an easy way around this problem:
The A6500 has no clean headphone jack output. The only way to get audio into the camera is through the mic input jack, which breaks out of the signal chain, hence introducing noise and impedance mismatches. However, there is an option for using a 3rd party adapter that allows you to connect your headphones via the 1/8" minijack on top of the camera body itself. This method does not require any adapters (in fact it doesn't require anything at all) and is simply plug-and-play; however, it means you cannot use your headphones while simultaneously recording audio from another source (there's no clean way around this).
Most of the HDMI to HDMI + Audio splitters don't work. The reason is that they don't output sound when connected to a camera like the Sony A6500.
The reason for this isn't because the audio is being disabled by default, but rather because of how the HDMI protocol works on this camera.
The Sony A6500 has only one direct-link output (i.e., it can only transfer image data and not audio), which means that if you want to record video with an external monitor, your options are either:
Use a cable such as an HDMI to SDI adapter or USB Type-C connection (both of which will also allow you to transmit sound).
Use an external recorder such as a Blackmagic Design Pocket Cinema Camera 4K or Atomos Ninja V (which will also allow you to transmit sound).
If you're shooting in a loud environment, or if you just want to make sure that your audio is being recorded at a safe volume level, then an adapter with an inline volume controller can be useful. Inline volume controllers are simple devices that allow you to adjust the volume of the audio coming from your camera. They're generally very affordable and easy to use: just plug them in between your camera and headphones (or speakers), adjust the knob until it's at a comfortable listening level, and then enjoy quiet recording sessions.
If you want to use a Sony menu-based LUT with your external monitor, you must set the monitor to "S-Log2" and not "S-Log3". You can then use your LUTs through HDMI in camera.
The A6500 has no clean headphone jack output, which makes it difficult to monitor audio out of the camera while shooting video. There are two options for monitoring audio:
Use an adapter with inline volume controller + headphones or earbuds
Go to the monitor's menu.
Select "Color Mode".
Change the "S-Log2" setting to "S-Gamut/S-Log3".
Exit the menu after you've changed it, and your mirrorless camera should be able to display its images on your external monitor with a wider color gamut than before.
You can also change the saturation levels and color temperature of the monitor's menu. To do this:
Set the monitor to "S-Gamut/S-Log3." (This is what Sony recommends when using their cameras.)
If you're not using a Sony camera, try setting it to "S-Log2."
Set the camera’s playback volume (MENU > Camera Settings 2 > Volume Settings) to a low or mid level.
Audio levels that are too high can cause distortion, so it is best to keep them in the middle range.
To get a clean audio signal out of your camera, you'll need to use an adapter that has a volume control. The best option is the Sony LA-EA3, which also supports focus peaking and supports autofocus in OVF mode.
You can use the Sony menu-based LUTs as well. You can change saturation levels and color temperature in the monitor's menu—just make sure to set its playback volume (MENU > Camera Settings 2 > Volume Settings) before connecting it to your camera.
This is a complicated topic, and I hope the above helps you sort out the options. The Sony menu-based LUTs are useful, but they don't work with every monitor and they may be too subtle for some. If you want to use a clean headphone output instead of an external monitor, consider buying an adapter with volume control and/or setting up your camera's audio playback levels so they're not too loud on set or during shooting (120dB+).