Auto-Answer Hybrid
JK Audio AutoHybrid Front

Not Just Another Half Duplex Auto-Coupler.

This simple, passive, auto-answer/disconnect telephone line hybrid allows simultaneous send and receive audio through analog telephone lines. Suitable for monitoring remote locations, IFB feeds, and many simple studio, conferencing, and PA telephone interface applications.

Learn More Details Specs

Product Details

Features AH LTD
Enable/Disable Auto-Answer
Excellent Separation of Caller and Talent Voice
16-bit DSP technology
Hybrid Null Adjust (Up to 20 dB Separation)
Proprietary Auto Null Algorithm (50 dB null)
Front Panel Off-Hook LED
Send XLR Line Input
Caller XLR Line Output
Send and Caller Signal Level LEDs
Remote Control Terminals
Guest Module 1 Remote Control Jack
Rack Mountable
Passive Design (No Battery or AC Required)
Made in America
Approved for Sale in Europe and Australia
JK Audio RA4

Rack Panel

This small desktop unit easily converts to a rack-mount unit using the optional RA4 Rack Panel. The RA4 holds 4 AutoHybrids in a 1U rack space.

Full Duplex

Yes, you can send and receive audio at the same time. The dual transformer hybrid is capable of 20 dB nominal trans-hybrid loss. In other words, your transmit signal will appear mixed with the receive signal, but at a level 20 dB lower than it was sent into the phone line.


The "Auto" feature is very simple. When the "Auto" switch is selected, AutoHybrid will answer on the first ring. The phone line will remain off-hook, until either the Drop button is depressed, or until the phone company releases the line.

JK Audio AutoHybrid Back


Input Female XLR
Impedance 1k ohms
Level 500 mV RMS (-4 dBu nom, +6 dBu max)
Insertion Loss 11dB Send XLR to Phone Line
Output Balanced Male XLR
Impedance 600 ohms
Level 200 mV RMS (-12 dBu nom)
Screw Terminals Off-hook Control (+5VDC Momentary)
Release Control (+5VDC Momentary)
OH LED Signal (pulled to ground on OH)
Phone Line RJ11C
Aux Phone RJ11C
Isolation 1500 VAC
Ringer 0.8B REN
Frequency Response Telephone Side 200 Hz - 3600 Hz
Size 4” x 5” x 1.5” (10.5 x 13 x 4 cm)
Weight 12 oz.