(EDIT: Audio still bleeds, but there is no delay.)

The issue: Users are encountering audio bleed from the FT-710 microphone input when using the USB device, even with the monitor level set to zero.

Numerous individuals, including myself, have experienced a persistent issue with the FT-710 USB audio. When utilizing computer or mixer headphones connected to through the USB soundcard on the FT-710, one can hear their own voice with a delay, despite having the monitor level adjusted to zero.

Despite extensive research and forum exploration, I could not find a software solution to resolve this issue. I had grown accustomed to the delayed voice feedback.

Contrary to suggestions that RF interference was the culprit, I ruled out this possibility. If RF were the problem, the voice feedback would be instantaneous. Instead, it appears to be a digital-to-analog conversion issue within the driver, allowing audio bleed and introducing a significant delay in the conversion process. Whether this is a hardware-related problem remains uncertain without an official response from Yaesu.

My setup involves routing audio through a Presonus Studio 24c to separate PC audio from the FT-710’s audio. The output is then directed to a basic analog mixer for adjustments in low, mid, and high frequencies. However, my goal was to eliminate my voice entirely from the headphones. Inspired by a comment mentioning a line level on the back panel and recalling a passage in the user manual regarding “RTTY/DATA,” I devised a solution.

Solution Part 1: Creating a Cable
Acquire a 6-pin mini-DIN cable and connect PIN 6 (DATA OUT) to the TIP of a mono 1/4 TRS. Connect the shell line of the DIN cable to the sleeve/shield of the 1/4 TRS.

Issue: Ground loop causing a significant whine.

Solution Part 2: Adding an Impedance Transformer
Utilize a cost-effective DI Audio Box purchased from Amazon for approximately $13. Plug the 1/4 inch into the DI box, disable the ground, set the attenuation to -0 dB, and connect a 3-pin XLR to the mixer. If interfacing with another device, results may vary based on different DI box types. Alternatively, addressing station equipment grounding may eliminate the ground loop whine.

This solution has effectively resolved the problem for me.

Cheers! de W0WC