News & Reviews

JK Audio Cell Phone Adapter to the Rescue

Radio World - May 22, 2002
by Frank Beacham

It was shortly after the collapse of the World Trade Center when New Yorkers rediscovered the value of cell phones. For journalists, working from makeshift newsrooms throughout the chaotic city, the portable phone became a lifeline to the breaking story around them.

It was during this period of iffy landline service that I confronted a serious shortcoming in my reporter's sound kit: I had no simple way to record clean, two-way audio interviews over a cell phone.

Telephone interface experts
I called the telephone interface experts, JK Audio in Sandwich, Il., to see if they made an adapter for such a purpose.

JK makes a line of professional-quality phone recording devices for just about every application. These should not be confused with the plastic gizmos sold at Radio Shack. Not only do JK interfaces work reliably, each one is built into virtually bulletproof metal box that will probably outlast its user.

The good news is JK had two new cell phone interfaces near completion. A short time later the CellTap, a simple wireless telephone tap, and the Daptor Two, a more sophisticated tap for remote broadcasts, arrived at my door for evaluation.

The CellTap ($79), is a winner. Every journalist that works with sound needs this tiny portable interface that allows the recording of cell phone audio with an automatic mix of both sides of the conversation.

When landlines are down, or a reporter is working in isolated field conditions, the CellTap allows interviews to go on in a completely mobile newsroom.

A 2-inch by 2-inch by 1.3-inch die cast aluminum cube, weighing only 3.5 ounces, the CellTap links together your cell phone, recorder and earpiece. It comes with two cables. Plug one into the 2.5mm earpiece jack of the phone and the other into the recording device. Then plug your earpiece into the CellTap. That is it - no levels to set. Just hit record. It is passive; no AC or battery power is needed.

My tests using a Motorola V60 phone on the Verizon network and a Sony MZ-B3 MiniDisc recorder worked flawlessly. The audio was clean and the conversation mix was perfect.

The CellTap also allows a group to listen to a conversation. Simply connect a powered speaker to the audio output jack and, presto, you have conferencing capability. Everyone in the room can hear the cell phone conversation, but only the person wearing the earpiece can talk to the distant party. While it is not a substitute for a speakerphone, this setup may be more suitable in that it limits the number of talkers and avoids confusion.

Audio transit
Daptor Two ($179), adds the capability of sending and receiving audio from a mixer or tape recorder through the cell phone.

As with the CellTap, your cell phone will recognize the device as a headset, which will disable the phone's internal mouthpiece and receiver. Since Daptor Two replaces the headset, the user must provide a microphone and preamplifier, and a headphone and amplifier to allow a cellular conversation.

Encased in a 4.4-inch by2.7-inch by 1.2-inch aluminum case that weighs seven ounces, the Daptor Two has both XLR and 1/4-inch input and output connectors. Only one type of connector can be used at the same time, however.

The device was designed to take advantage of the increasing number of wireless phones that accept third party headsets and earpieces. It includes a circuit that emulates the electrical characteristics of these headsets.

Both CellTap and Daptor Two can be used only with phones equipped with a common 2.5mm jack. For models with proprietary headset connectors, the manufacturer often sells a 2.5mm adapter as an option.

Niche filled
JK Audio has once again filled an important niche in the journalist's continuing struggle to conquer the slings and arrows of our nation's telephone system. CellTap and Daptor Two are important additions whose value will be most appreciated in times of emergency.

For more information about JK Audio telephone interface products, contact the company in Illinois at (815) 786-2929; or toll free at (800) 552-8346; or visit

Frank Beacham is a New York City-based writer and producer. Visit his web site at