Bose A30 - Unwanted Noise

[MarkO]

I have the new Bose A30 headsets in my DA62. After engine start I get a lot of static and unwanted noise. My fix has been to unplug the headset and plug it back in - this fixes it until the next power interruption. Bose has advised me they have issued a bulletin, and the solution is to put batteries in the headset control module; even though the headset won't use the battery power, it will resolve the issue.

I would put a copy of the bulletin up, but I can't figure out how to add a picture or document!! Cheers Mark

[Rich]

This behavior should also occur using the dual plug -> 6-pin LEMO adapter I came up with last year. It supplies panel power from the exact same circuit as the Diamond-installed LEMO jack. I haven't had the opportunity to test the A30, but did use an A20 without batteries for some time without issue. Something to know about this circuit is that it is fed off the audio panel breaker though a 100Ω 10W (on 28V systems) resistor. Superficially, this circuit appears identical in all Diamonds. But it would be instructive if someone has an A30 they could test out battery-less in a DA40-180.

The power to any and all panel-powered headsets (potentially as many as 7 in a DA62) goes through this one resistor. I've been running up to 3 headsets, but haven't yet tried the max (for me) of 4. Two of them are Zulu 3's with no provision for a battery. The other is my Delta Zulu with the recharging Li Ion battery. In the latter case the headset will occasionally draw more power to recharge the battery as it decides it's needed. Plus it has the CO detection, audio modulation for speech enhancement and runs bluetooth at all times. So far no issues.

[Rich]

This doesn't seem like a major hardship if all you have to do is keep batteries installed. But they probably should be checked out/replaced from time to time. Batteries can sometimes come to leak, irrespective of how much use they've seen.

[steve_falconer]

Rich, I don’t hear screeching on startup. Audio quality is clear.

But the Bose A30 with Lemo plug and your adapter doesn’t power on for me unless I have batteries installed. I’ve wondered if it was working, but hadn’t done testing or replaced my battery yet. It works well for my Lemo Delta Zulu without battery installed.

[Rich]

Rich, I don’t hear screeching on startup. Audio quality is clear.

But the Bose A30 with Lemo plug and your adapter doesn’t power on for me unless I have batteries installed. I’ve wondered if it was working, but hadn’t done testing or replaced my battery yet. It works well for my Lemo Delta Zulu without battery installed.

Does the A30 auto-power-on with batteries installed?

[MackAttack]

I was about to respond that I bought an A30 at OSH and didn’t have any issues on the flight back to Houston in my 62, when I realized that I put the batteries that came with it into the A30 while unboxing, just because they were there. Good thing that I did - will keep them there for now apparently!

Overall, I like the headset a lot and it is just a bit more comfortable than the already-great A20.

[Rich]

Rich, I don’t hear screeching on startup. Audio quality is clear.

But the Bose A30 with Lemo plug and your adapter doesn’t power on for me unless I have batteries installed. I’ve wondered if it was working, but hadn’t done testing or replaced my battery yet. It works well for my Lemo Delta Zulu without battery installed.

Does the A30 auto-power-on with batteries installed?

Related question. Can the A30 be manually activated with the power button in the absence of batteries?

[steve_falconer]

Rich, It wouldn’t turn on manually without batteries with the adapter when I tried before a flight a couple times. I broke out the spare batteries to go fly and worry later. I am able to run the Delta Zulu without a battery installed. I have auto-on enabled for both. I need to do more testing like trying the other adapter that works with the Delta Zulu. That being said, I’m on the same set of batteries after 48 hours of Hobbs time and connected to ForeFlight Bluetooth most of the time, so seems like I’m getting some benefit. I’ll try some testing tomorrow after a post maintenance flight (oil change and RSB 40-094). Thanks for following up!

Rich, I don’t hear screeching on startup. Audio quality is clear.

But the Bose A30 with Lemo plug and your adapter doesn’t power on for me unless I have batteries installed. I’ve wondered if it was working, but hadn’t done testing or replaced my battery yet. It works well for my Lemo Delta Zulu without battery installed.

Does the A30 auto-power-on with batteries installed?

Related question. Can the A30 be manually activated with the power button in the absence of batteries?

[steve_falconer]

Rich, I did more testing today. Confirmed the batteries are required even to manually turn it on with your adapter. BUT it does keep running WITH noise cancelling even if the batteries are removed after it’s been started. So I’m guessing I’ll have super extended battery life which also works. The AA batteries are approaching almost 50 hours now and will tick over a couple above that this weekend.

So it looks like it works better with Delta Zulu and Bose A20 headsets. In case there is difference for someone else and their A30, I have the A30s with Bluetooth.

[Rich]

The evidence is that the A30 somehow requires extra power to "boot up" that the Diamond system, for whatever reason, won't supply, but is happy once it's been started. The batteries somehow fill the gap for the presumably short time required and then are not used. So far this is unique to this model headset.