What is the difference between passive and active adapters and which one should I choose for my DSLR camera?

This is a common question that we get all the time. We will look at two of our adapters: the passive DXA-SLR PURE and active DXA-SLR ULTRA.

Quite simply, passive means that there is no electronics in the signal path. In the case of our DXA-SLR PURE, the signal flows through transformers that covert the balanced inputs from the XLR connectors to an unbalanced output for connection to the camera. There is no gain or phantom provided – the output signal will only be as strong as the input signal. However, there are many advantages in using passive gear. The main one being that no power or batteries are required. The signal will still pass through the adapter even with no battery installed or when it is turned off. The battery is only used for the VU Meter and headphone amplifier. Also, since there is no electronics to get in the way, the adapter delivers pure, clean audio to the camera. It is also very hard to clip the audio even with very high signal levels. Passive adapters are ideal for use with wireless mics or to connect to a mixing board as no additional amplification is necessary. It can also be used with some high output wired microphones such as the popular Rode VideoMic Pro which as a +20dB boost feature.

Conversely, active means that there is electronics in the signal path – usually a preamplifier to provide gain. Our DXA-SLR ULTRA provides up to 30dB of gain to provide plenty of punch from virtually any microphone. It also supplies 48 volt phantom power when needed. This adapter must be powered in order to operate – it uses a single 9 volt battery. The main advantage in using an active adapter is the preamplifier which will provide a strong clean signal to the input of the camera. This allows you to minimize the gain of the preamplifiers in the camera for very clean audio. The lower the gain of the camera preamplifiers, the lower the noise. By using an external low-noise preamplifier, you can dramatically increase the signal-to-noise ratio of the captured audio to match or exceed the quality of a typical digital audio recorder. Capturing audio directly to the camera is also much easier as no syncing is required in post.

Therefore, which adapter you choose depends on what gear you would like to attach to it. Both the DXA-SLR PURE and DXA-SLR ULTRA will allow you to capture exceptional audio directly to your camera. Please visit our website at for more information.

02_DXA-SLR PURE Prosp2