Headset issues - plug standoff adjustment?

Hi everyone,

I just bought an RV12 and am in the process of flying it back to the East coast. While purchasing the plane I had a lot of trouble with my Bose A20s.

The headsets are known functional.

In the right seat, where I sat during a demo flight with the seller, plugging in my headsets caused a whining noise from somewhere in the plane - could have been from my headsets or another source. I didn't actually put it to my ear to verify where the sound was emitted from. The sellers old DCs worked fine, albeit with some static.

In the left seat when I keyed the mic with my A20s it produced a solid tone - too obtrusive to think about the call I was trying to make. Audio coming into the headsets is almost unintelligible, unless the plug is pulled ~1/8" out of its socket. If it's in juuust the right spot the audio is perfect. The seller's Lightspeed Zulus work perfectly and he was kind enough to lend the to me for my journey back.

When I flew with a CFI to get signed off for insurance he stated that the standoffs might need to be adjusted. I gather this is some barrel adjuster or similar that determines exactly how far in the plug can go.

Is he on the right track? Any other ideas if not? I tried googling for instructions but come up empty, so I'm not sure if my terminology here is correct or not.

For the record, these are the LEMO headsets with the GA adapter.

TLDR: My headset only wants to behave in this plane when it's plugged not quite all the way in. How do I rectify this?

Headset issues

A few years back I had similar issues when I upgraded from a DC 13.4 to a Bose A20. There are three terminals on the jack with one going to ground. An avionics shop instructed me to run a jumper between the other two terminals. I believe it was due to the jack being mono (versus stereo), thus requiring the jumper. Also, I have a note that I adjusted the radio side tone to mitigate extraneous bad noise.
Hope this helps.

Jim Diehl 7A

Switch the headset to mono, switch located under the battery.

So I just checked and my Bose were already on mono, but thanks for the suggestion Walt.

My GA adapter plugs and the seller's Zulu plugs have a little different style so I have ordered the new version of the adapter from Bose. It appears to match the plug of the Zulus pretty closely and should be delivered tomorrow. Fingers crossed that it will be that easy a fix.

I've also had my fiancé ship out the pair of Zulus that I have for passengers just in case the new adapter doesn't work.

I need to get the headsets back to the seller in time for him to pick up his new RV6, so I'm doing this debugging while on a planned stopover with family in CO.

If you have a stereo headset jack and audio system, you will want to run your headset in stereo mode or it will short the ring to ground and might cause issues.

When you pull the mono plug out partially, it removes the short from ring to ground.



Steve

Thanks Steve, I’ll try it set to stereo as well.

For what it’s worth, I had similar trouble after a panel upgrade to all new Garmin stuff. I must have tried 8 different headsets with varying results. After a lot of trouble shooting over several weeks, we discovered the left and right channels were reversed on a plug behind the panel. Works great now!

Having the same problem. Bose A20 and Lightspeed Zulu won't work. But my old Bose X works perfectly. This is with Dynon equipment.

As Jerry mentioned, check the wiring on those jacks! The newer Garmin stuff drops all audio to the left channel (mono) if it sees what it thinks is a short. I have even seen reputable documentation that has jacks wired up opposite.

Ok so the new Bose LEMO to GA adapter did the trick.


As you can see in the attached photos, one of the prongs is shaped differently between versions. Maybe the new one is stereo and the old is mono? Not really sure but it works!

Thanks for the suggestions everyone!