[WT-support] Getting Realtek HD Audio Manager to work on a Lenovo with MMTTY or the Contest Recorder

[Bob Wilson, N6TV]

This information may apply to anyone trying to get decent audio from a
radio into a modern Windows notebook computer, for use by MMTTY or the
Win-Test Contest Recorder.

N6PN was having trouble getting clean audio from LINE OUT on his Elecraft
K3 into his Lenovo X240 running Windows 7.  This laptop doesn't have a
simple "MIC" input.  Like many of the newer notebook computers, this
machine has a single 4-conductor (TRRS) jack combining microphone inputs
and stereo headphone outputs into one connector, instead of separate mic.
and headphone connectors.  Lenovo apparently uses:

Sleeve = Microphone input
Ring 2 = Ground
Ring 1 = Right channel output
Tip    = Left channel output

It seems strange not to use the sleeve as a ground, but apparently that's
the way Lenovo (and others) now do it.

To split the connector into separate mic. and heaphone jacks, we used a
"headset adapter / splitter", pictured here:

http://www.amazon.com/Conwork-Splitter-headsets-headphone-microphone/dp/B00V1W9YM6/

We connected K3 LINE OUT to the MIC jack. on this splitter.  Then we
connected headphones to the stereo jack of the splitter, and enabled the
Windows "Listen to this device" feature to hear what was going into the PC
(see
http://windows.microsoft.com/en-us/windows/connect-audio-device#1TC=windows-7,
then expand the section "To connect a music player or other audio device to
your laptop").

First thing I noticed was that there was a tremendous pulsing white noise
coming from the GearMo USB-to-Serial adapter plugged in to the USB port,
right next to the headphone/microphone jack.  The noise was in sync with
the flashing lights on the adapter.  Moving the USB-to-Serial adapter to
another USB port on the opposite side of the laptop fixed that problem.

The second issue was very strange.  We just could not get the audio levels
adjusted high enough, and it seemed that BOTH the ambient room noise from
the built-in MIC of the notebook computer *and* the audio feed from the
radio were being combined no matter what we tried.  There seemed to be no
easy way to manually disable just the built-in mic. of the computer; the
"mute mic." button muted all inputs.

Here is a solution we finally came up with after much trial and error.  The
devices must be connected in a specific order, and you must have a
condenser mic. handy (such as one on the Yamaha CM-500 headset).

   1. Using the RealTek HD Audio Manager, switch the audio system from HD
   multi-channel mode to "Classic" mode, and disable all sound effects, room
   correction, and microphone effects.
   2. (Very important) Connect a headphone AND a PC microphone (e.g a
   headset with a  condenser mic.) into the TRRS adapter.
   3. Plug the TRRS adapter (with the headset and mic. already connected to
   both jacks on the adapter) into the PC.  Do not plug an empty adapter in to
   the PC.
   4. At this point (finally), the PC detects that a headset and mic. are
   connected, and it mutes the built-in microphone.  If you speak in to the
   headset mic. you should hear yourself in the headphones (when "Listen to
   This Device" is enabled).  There is considerable audio delay.  If you tap
   on the PC, you should hear no audio from the built-in mic.

   The Lenovo circuitry or RealTek software is apparently looking to detect
   a real PC microphone that consumes current, not an audio output from a
   radio that consumes no current.  If you plug the radio output directly into
   the PC, it will not mute the built-in mic. and you'll have all the room
   noise recorded instead of your radio.
   5. Unplug ONLY the pink condenser mic. connector from the ADAPTER
    (while leaving the adapter plugged into the PC)
   6. Connect a stereo cable from LINE OUT on the radio into the Mic. jack
   on the adapter.
   7. On a K3, use CONFIG:LIN OUT in the K3 menu to adjust recording
   levels, keeping the Real Tek Audio Manager microphone sliders at center of
   range, and MIC. BOOST at 0 dB.
   8. At this point, only clean audio from the radio should be recorded by
   the Lenovo sound card, and you can run MMTTY or 2Tone or the Win-Test
   Contest Recorder.

All of this was discovered while trying to clean up audio noise displayed
by Faros (VE3NEA's very cool automated NCDXF beacon monitor).  Selecting
"DVD Quality" (48000 Hz sampling) in the RealTek HD Audio Manager seemed to
be more compatible with Faros than 44100 Hz audio).

73,
Bob, N6TV
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