The Fix Audio Designs Collaborator HPC-4 is a headphone/monitor amp and talkback system. The Collaborator is an all-analog unit that fits next to your console, on your desktop or a mic stand using its threaded base. There are four individual headphone amps with separate volume controls so each person receives the best possible sound as loud or as soft as they desire.
The Collaborator's built-in Talkback microphone has an adjustable mic gain and blend control to mix its sound right into the headphone mix. If you are out in the studio singing with others and all on headphones, anyone else in the room (without phones on) is clearly heard so no need to remove your phones to hear them say something. Tracking sessions with loud guitars and drums and with everyone wearing headphones connected to the Collaborator, plug in a standard keyboard pedal footswitch to toggle the talkback on/off for hands-free operation. Awesome! You'll wonder how you ever got along before!
Besides the jack for the footswitch, Collaborator's rear panel has a pair of +4dBU line level XLR (L/R) inputs as well as a 1/4-inch stereo input jack for patching a feed from another cue system or the headphone output jack from your USB interface.
I compared the Collaborator to my existing cue system that uses a 100-watt/channel Hafler stereo amp and Simons CB-4 headphone boxes. I found no big difference—although the Collaborator has more gain for super quiet audio. I also found no problem driving low impedance phones such as my power-hungry Audeze LCD-X planar magnetic models. The Collaborator will go louder than loud and works great for drummers using any brand of headphones.
The Collaborator sells for $499 and is a great investment in your studio that I highly recommend.