Learning about Plug Sizes

5th in a series of articles about headphones and headsets.

A plug is a plug is a plug right? At first glance, the expectation is that the connection from a headphone or headset to a computer or media player would be all the same, but jackbox, headphone and headset uses are so varied, Califone in fact offers six different styles of plugs. Why the need for so many and which criteria should you use when choosing?

The answers behind this are pretty straight forward and can be broken down into two main applications – headphones (listening only) or headsets (listening and replying).

Traditionally, headphones require only a single plug. In the classroom, monaural (language learning) activities need a solitary 1/4″ plug (such as the 2924AV shown second from the right below), while stereo or computer-based listening requires a 3.5mm plug such as the 2800-BL on the far right. There are straight 3.5mm plugs and right angle 3.5mm plugs, which Califone uses on its Listening First series and Sound Alert headphones. These were designed for use by younger children and the right angle plug has a higher resistance to accidental pull out. The 3068AV however, is a switchable monaural/stereo headphone and comes with a 3.5mm plug (shown far left) with a snap-on 1/4″ adapter.

Plugs shown from left to right are attached to: 3068AV (which includes a snap-on 1/4″ adapter), 3064USB, 3064AV, 2964AV, 2924AV, 2810-PA (the right angle stereo plug).

Before digital learning became the norm, headsets traditionally required two plugs (one for listening and one for the audible reply) such as the monaural 2964AV (third from the right), or the stereo 3064AV (third from the left with two 3.5mm plugs). Growing acceptance of USB technology however has seen the growth of headsets with a USB plug instead (3064USB, 3068MUSB, 3066USB, 4100USB, Titanium series). An advantage of a USB plug is it allows for faster data transference, making headsets with a USB plug the preferred technology choice for distance learning and gaming applications.

Another important identifier when you’re looking at a plug is to count the number of small black rings on the tip (excluding USB plugs). If there is a single ring, that means it’s mono (monaural). Two rings means it’s a stereo connection. In the above image there are nine plugs shown. The three largest plugs (second, third, and fourth from the right) all have a single black ring and are therefore mono. All of the rest are stereo.

Newer still is the To Go plug. This is used only on headsets. It can be found on the 3068 headset,  solid-colored (2800-xx) and animal-themed (2810-xx) Listening First headsets, Discovery headset (DS-8VT), Lightweight Stereo multimedia headset (3065AVT), Deluxe Multimedia Stereo headset (3066AVT), and the 4100 (4100AVT), and one Titanium (HPK-1010T) headset. This type of plug has a third black ring so its single 3.5mmplug can take advantage of the microphone feature – enabling students to listen to audio and talk back while connected to mobile devices (which typically have only a single connection port).

Jackboxes also share these features.

Read the next article, or the previous article, or return to the first article in the series.


Helping teachers and students with educationally appropriate classroom AV equipment since 1947.