AT Pro headphone adapter malfunction????

[Chuck121]

I just got my adapter,and plugged in my headphones only to discover that it works,but doesn't shut off the AT Pro's built in speakers. I disconnected them and plugged in the original Garrett Headphones and this does shut off the main speakers? Anyone else have this happen and is this normal?

 

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[Sandman]

I don't have the adapter and use the waterproof phones from Garrett. Does your headphones have switches for stereo and mono? Maybe Garrett only wants us to use their phones.

 

[Kayaker]

... Maybe Garrett only wants us to use their phones.

I got the Garrett adapter and have used it with iPod earphones, iPhone earphones with/mic, cheap headphones I got with my Bounty Hunter IV (for "free" from Kellyco... ha), and with a wireless Auvio setup I'm working on now. All of them work fine for me.

 

[Kayaker]

... Maybe Garrett only wants us to use their phones.

I got the Garrett adapter and have used it with iPod earphones, iPhone earphones with/mic, cheap headphones I got with my Bounty Hunter IV (for "free" from Kellyco... ha), and with a wireless Auvio setup I'm working on now. All of them work fine for me.

Chuck, I humbly stand corrected! Although my WIRED headphones all work fine, the Auvio wireless transmitter/headphone does the same thing your headphones do. At first I though it might be some mechanical/switch issue, like maybe the plug wasn't hitting the bottom of the jack, but that doesn't seem to be the case. Even if I use a headphone extension cord and plug the wireless transmitter into THAT, rather than directly into the Garrett adapter... it still doesn't cut off the internal speaker.

My GUESS is that the detector knows when to switch the speaker off by sensing the low impedance of the headphones when they're plugged in. Maybe my wireless setup (or YOUR headphones) have an impedance significantly different (higher) than that of most standard headphones(?).

I suppose I'll send an e-mail to Garrett Customer Support, but I not very hopeful that they'll care enough about my particular issue/question to help with it. If it IS an impedence issue, I don't know of a way to resolve it.

Edit - I did a bit more poking around on the web and think I'll try adding a resistor across the headphone ring and tip connections. This will be in parallel to the headphone impedance and will bring down the impedance that the detector "sees" when the headphone is plugged in. I'll try to get to Radio Shack tomorrow at lunch and pick up a few resistors. Based on what I'm reading (and guessing at the headphone impedance), I've got an idea of what value might work. It might lower the headphone volume though, but I don't know how much, if at all. If I find something that works for my setup, I'll post here.... not sure if anybody is interested.

Disclaimer - I don't claim to be an electronics engineer but was an electronics technician in a previous career over 20 years ago... so I'm fumbling my way through this.

 

[Kayaker]

Hi Chuck,
Hope you're still following this thread. I found the answer on another forum. There is a simple solution you can try without cobbling together something like I thought. As suggested, I bought this Volume Control/Headphone Extension from Radio Shack for $9.99 and put it between the AT Pro Adapter and my headphone plug. Works like a champ!


Radio Shack Volume Control/Headphone Extension Part Number - 42-2559

Here it is hooked up to my wireless transmitter -

Let us know if you try it and how it works! - Kayaker

 

[Born2Dtect]

Chuck121,

The audio plug on a set of headphones use a standard TSR (tip ring sleeve) 1/4" or 1/8". Normally the detector or whatever device the connect to has a mating connector with a break before make connection. Short version the jack mechanically breaks the internal speaker connection then connects to the head phone. All this happens automatically when the headphone are plugged in and removed. I would suspect a faulty (deform or badly design connector adapter).

Ed Donovan

 

[Kayaker]

Chuck121,

The audio plug on a set of headphones use a standard TSR (tip ring sleeve) 1/4" or 1/8". Normally the detector or whatever device the connect to has a mating connector with a break before make connection. Short version the jack mechanically breaks the internal speaker connection then connects to the head phone. All this happens automatically when the headphone are plugged in and removed. I would suspect a faulty (deform or badly design connector adapter).

Ed Donovan

Hi Ed,
Whatever the reason, the volume control works. And for others, as well. It's certainly worth a shot.

I'll give you my thoughts on it... for whatever they're worth (maybe nothing! ha!)... From what I've read, some detectors do not use a mechanical switch but sense the impedance of the headphones. This is why plugging in JUST a 1/4 inch to 3.5 mm adapter doesn't turn off the speaker. This would also explain why my wireless transmitter is not recognized as "headphones connected" if the transmitter's input impedance is very high. Also, putting this volume control between the AT Pro adapter and my transmitter works, but just using a simple extension without a volume control does nothing. So I do suspect it's an impedance issue, with my transmitter being too high (1k or 2k?). Measuring the volume control cord's resistance, it seems to be putting a 550 ohm load in parallel with the headphone input. And adding that in the circuit brings down the impedance low enough to turn off the speaker. That's my story and I'm stickin' to it! ;-) Actually, I certainly defer to you if this doesn't make sense, though. My electronic experience is from a prior career, 20 years ago.

Happy Hunting - Kayaker