Icom’s new IC-9700 can receive two bands at the same time. In DV mode, it can decode two digital signals at the same time, something even the IC-5100 cannot do. Since it has a stereo USB audio interface build in, it’s logical to expect the IC-9700 to output main and sub band audio at the same time over USB as well.

Some sources on the Internet mention that only main band audio is output via USB. Given all the “at the same time” features of the IC-9700, I resisted to believe this to be true. So … let’s check the schematics first.

Not only in the block diagram, but also in the schematic, it can be seen that main audio (UAFA) is connected to V-IN-Left and sub audio (UAFB) is connected to V-IN-Right of the USB audio codec.

Next step, is to check Windows sound settings. You can type Win-R (run) and enter mmsys.cpl to open the sound settings applet without searching through (1.0E+6) setting screens first. Now select the Recording tab, my IC-9700 is labelled as 3- USB Audio CODEC. Note that Windows 10 assumes this to be a Microphone…

Next select your device to show the device properties, then click on the Listen tab and check the Listen to this device box to route incoming audio to your computer’s Playback device. Now IC-9700 audio should come through your computer’s speakers.

Finally, select the Advanced tab and and verify the Default Format. Since Microsoft assumes this device to be a Microphone, this defaults to 1 channel, 16 bit, 44100 Hz (CD Quality) ….

After changing this setting to 2 channel, 16 bit, 44100 Hz (CD Quality), main band audio of my IC-9700 comes out of the left computer speaker and sub band audio out of the right one. This also works in satellite mode, where the downlink is on the main band. I love “at the same time” …

2 Comments

  1. Frank – excellent information. I had stupidly believed that the audio stream was only one channel. I read it on the Internet and I believed it – bad idea. I even set up an analogue line from the back audio jack for a second decoder. Then I was sent a link to your site and .. “D-oh”.
    Thank you (and also for the IC-7300 sample rate info – very clearly written).
    Jim

    1. Author

      Hi Jim,
      Glad to help. Have fun with your IC-9700.
      73 Frank

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