Aviation headset music input..

BellyUpFish

BellyUpFish

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Ok- I've grown used to my Lightspeed's but have switched from them to the Halo headset, I love it. However, I cannot get my music into it. So I am looking for a gadget.

I was planning on picking up this: http://www.marvgolden.com/mg-20-ipod-mp3-cd-player-headset-adapter.html

However, I just noticed it is OOS.

Anyone have any ideas? It's only $35, so that's kinda where I am looking to spend. I can wait for it to come back in stock, but thought I'd see if anyone else had another idea.
 
BellyUpFish said:
Ok- I've grown used to my Lightspeed's but have switched from them to the Halo headset, I love it. However, I cannot get my music into it. So I am looking for a gadget.

I was planning on picking up this: http://www.marvgolden.com/mg-20-ipod-mp3-cd-player-headset-adapter.html

However, I just noticed it is OOS.

Anyone have any ideas? It's only $35, so that's kinda where I am looking to spend. I can wait for it to come back in stock, but thought I'd see if anyone else had another idea.
Click to expand...
Make sure you call and talk to them before trying to order it!

Marv Golden's store is literally across the street from my plane at MYF. I have been trying to find something to do exactly what you are looking for. I use a David Clark ANR headset and it doesn't have the additional audio input, so I thought I'd find something that would allow me to pipe my XM radio or Ipod into the intercom. I bought an adapter similar to what you linked (although it looks slightly different). It played the music alright.....only problem is that as soon as you plug it into a mic jack, it automatically transmits over the freq!

I was wondering why it got so quiet on 122.75 around San Diego and then I realized that I was broadcasting XM radio. Not sure why it does that, but it does - even without the PTT switch depressed. It also seems to do that in any airplane.

Anyway, whatever you get, make sure it doesn't do that!
 
Anything you pipe into the mic jack is going to go out over the air when the radio is keyed... that second cable seems like a bad idea to even sell...
 
denverpilot said:
Anything you pipe into the mic jack is going to go out over the air when the radio is keyed... that second cable seems like a bad idea to even sell...
Click to expand...

The problem though, is that it seems to go hot and transmit as soon as it is plugged in without actually keying the mic
 
Fearless Tower said:
The problem though, is that it seems to go hot and transmit as soon as it is plugged in without actually keying the mic
Click to expand...

Does it do it when the cable is plugged in by itself, or only if the audio source is also plugged into the other end of the cable?

PTT is done by grounding the tip to the shield/ground on an aviation mic jack. Current flows from the radio and/or intercom to the normally open PTT switch(es), and when the voltage on the tip is grounded, the radio keys and switches from receive to transmit.

If the radio keys as soon as you plug *only* the cable in with nothing else attached to the cable, it's likely that the plug doesn't fit the jack correctly and tip is being shorted to ground right inside the aircraft's jack, but there's also a possibility that something screwy is going on inside the cable. Using an ohmmeter, you can test the cable when disconnected from everything and see if the tip is connected to anything. It should not be.

If the radio only keys once the audio source is plugged into the cable, the audio device is allowing current to flow between the tip and sleeve of the aircraft end of the cable, which are probably hooked to the tip and ring on the other end of the cable at the audio device.

If the latter, you may need a capacitor in-line to block the DC trying to flow, or a 1:1 audio transformer for the purists...

(The blocking capacitor creates an RC filter circuit with any upstream resistance in the cable, and can alter the quality of the audio a bit), depending on the resistance and capacitance values... not that it's going to matter much in a noisy aircraft.)

The other problem and also a likely culprit -- on the audio device end of the cable, you're dealing with a stereo connection where tip and ring are split into two (left and right, I forget which is which, but Google will find that), and shield which is ground.

You're taking two signals and feeding them to a mono jack. There's a few ways to handle that, but it could also be a source of where your pseudo-ground is showing up. Example, the iPod and iPhone actually use a four conductor plug, but that same jack will accept a standard 1/8" stereo jack which is only three conductor.

Your "sneak path" to ground from the aircraft tip might be something like that.

Google revealed this, which may help if you're into schematics and visuals...

http://www.aeroelectric.com/articles/micjack/micjack.html

The "extra ring" he talks about, found on many mic plugs, is called a "guard ring" and may or may not be grounded too (and/or causing your problem). I prefer the guard not to be grounded and floating instead, but have seen them both ways.
 
Fearless Tower said:
Actually....looking at the description of the one you linked to, it sounds like that is indeed what you want, but I'd still recommend calling and talking to them.

Here is the one I got:
http://www.marvgolden.com/mg-17-ipod-mp3-intercom-adapter.html

It broadcasts....
Click to expand...
Doesn't make any sense that they would design it to insert accessory audio on the input side of things, at the mic jack!! Plug any source into that jack, and it will go wherever mic audio usually goes. It is possible, of course, to get aux audio into an airplane intercom and isolate it from the radios themselves, but this is not the way. :no:

I agree that it's probably "pinned out" so that it's creating a closure on the PTT circuit, which only makes matters worse.

The only way this cable would work would be if you had an annunciator panel that allowed you to not transmit from that mic input... but then you have to keep switching that back to "transmit" every time you need to talk on the radio. And you'd have to pause your music. How convenient... NOT!!
 
BellyUpFish said:
Ok- I've grown used to my Lightspeed's but have switched from them to the Halo headset, I love it. However, I cannot get my music into it. So I am looking for a gadget.

I was planning on picking up this: http://www.marvgolden.com/mg-20-ipod-mp3-cd-player-headset-adapter.html

However, I just noticed it is OOS.

Anyone have any ideas? It's only $35, so that's kinda where I am looking to spend. I can wait for it to come back in stock, but thought I'd see if anyone else had another idea.
Click to expand...

Dont do it. I just bought one about eight weeks ago, a month later my iphone quit outputting sound, no problem, i just plugged it into my ipad......two weeks later the ipad quit... Apple determined that something had shorted out earphone jacks and replaced them under warranty even though it wasnt their fault. This $35 solution almost cost me $1400.

I did sucessfully use a device i found on sportys website for 6years. It was about $100 and used a AAA battery. I finally lost that one which led me to the one you are looking at. Now i am just using the earbuds, not comfortable but now im gun shy.


Sent from my iPad
 
I've known a few guys who took an old aviation headset, and and old pair of MP3 player head phones, cut the respective tips off them and (somehow with parts from Radio Shack) spliced them together. Plug the thing into an extra mic jack and you're all set; never had problem with phantom transmissions. Of course, you don't have ATC cutout, but as long as you're not blasting it, it shouldn't be a problem.
 
Hmmm, I guess I'm gonna have to get creative. I can't wear ear buds with the Halo and don't want to splice up another headset, I guess I have to keep looking.

I found one at Sporty's but it cuts out with squelch break and I don't want that.

Thanks guys..
 
There's this one at AS and, at first blush, it seems to be a better designed solution: http://www.aircraftspruce.com/catalog/avpages/headsetAdapter.php

It has the automute but that can be turned off. Hopefully, it has an auto off feature or, if you're like me, you'll be going through a lot of 9v batteries. I always forget to turn my ANR headsets off...good thing they have auto off.
 
Teller1900 said:
I've known a few guys who took an old aviation headset, and and old pair of MP3 player head phones, cut the respective tips off them and (somehow with parts from Radio Shack) spliced them together. Plug the thing into an extra mic jack and you're all set; never had problem with phantom transmissions. Of course, you don't have ATC cutout, but as long as you're not blasting it, it shouldn't be a problem.
Click to expand...
Yeah, that should work, as long as the adaptor isn't shorting those PTT pins. A much better idea than plugging it into the mic jack you're using to transmit.
 
BellyUpFish said:
Hmmm, I guess I'm gonna have to get creative. I can't wear ear buds with the Halo and don't want to splice up another headset, I guess I have to keep looking.

I found one at Sporty's but it cuts out with squelch break and I don't want that.

Thanks guys..
Click to expand...
the thing Teller described involves using not the era buds, but the (stereo)male plug that they come with. That goes into the output of your MP3 player, to carry that audio signal into a mic jack other than the one you're talking on (by splicing a standard headset mic plug onto it). As long as it's not wired "straight through", it shouldn't create a closure on that jack's PTT circuit.

the problem with this is that both male plugs are "tip, ring, sleeve"... the little guy for the MP3 player is stereo, so tip and ring are left and right "hot", and the sleeve is the ground. The mic plug normally is tip audio "hot", either the ring or sleeve is ground (I forget which)... that and the remaining conductor are wired to the PTT switch. The ground is also wired to the same ground as all the other audio stuff, so if the PTT switch is open, audio going into that jack goes wherever you want except over the air. Close the switch, and a relay goes off that sends the audio to the transmit circuit of the radio.
So you'd have to sum left and right from your MP3 player, so as not to be using that third part of the plug (any termination on it would work like a closure, just like a PTT switch). simplest way is to put tip and ring (left and right) together on just the tip of the mic plug... that's an audio no-no, as it can create phase problems and make the music sound weird, but sometimes it works well enough (though I'm not sure why). You could also abandon the left or right channel, but that would sound pretty bad, unless your iPod playlist is all mono recordings. :D

But if I were to do this sort of "hack", I'd forget the mic circuit altogether, and just make a cable that comes out of the headphone jack, to insert the signal into your headset's speakers, along with everything else you'd hear from the intercom and radios. If you have a stereo headset, this will allow you to hear your music in stereo. Basically, this is just like the "Y" cable Teller described, only it's meant to plug into the plane's headphone jack, not the mic jack. No need to cut up your headset cable, either... it would be an adaptor, with a male mini-plug to go into the MP3 player, a female phono plug for the headset, and a male phono plug to go into your intercom.

Again, you're sticking two signals onto the same circuit without properly mixing them, but it should work well enough. Definitely less problem-prone than cramming two signals together on the input side of things. Only drawback is that it would only work for that one headset, not for all headsets on your intercom circuit.... unless you add yet another female phono plug (or two, or three) to the adaptor. the more headphones you add, though, the lower the impedance, and the typical aviation headset speakers are already not exactly a perfect match for an amplifier intended to drive earbud speakers. You could over-tax your MP3 player's amp. But in any case, if you use the output side- the headphone circuit, not the mic circuit- the music would never get transmitted over the radio.
 
Last edited:
Melting said:
Dont do it. I just bought one about eight weeks ago, a month later my iphone quit outputting sound, no problem, i just plugged it into my ipad......two weeks later the ipad quit... Apple determined that something had shorted out earphone jacks and replaced them under warranty even though it wasn't their fault. This $35 solution almost cost me $1400.
Click to expand...

Hehe. Melting. There's more than just audio on the Apple earphone jacks. They also have a mic input.

I'd have to guess that intercom was leaking power to the audio input.

Melting said:
I did sucessfully use a device i found on sportys website for 6years. It was about $100 and used a AAA battery. I finally lost that one which led me to the one you are looking at. Now i am just using the earbuds, not comfortable but now im gun shy.
Click to expand...

The PS Avionics Muse: http://www.ps-engineering.com/muse.shtml $349.95 list!!! Suuuuurrre. You can buy it for around $80.

Sent from my Macbook Pro
 
denverpilot said:
Does it do it when the cable is plugged in by itself, or only if the audio source is also plugged into the other end of the cable?

PTT is done by grounding the tip to the shield/ground on an aviation mic jack. Current flows from the radio and/or intercom to the normally open PTT switch(es), and when the voltage on the tip is grounded, the radio keys and switches from receive to transmit.

If the radio keys as soon as you plug *only* the cable in with nothing else attached to the cable, it's likely that the plug doesn't fit the jack correctly and tip is being shorted to ground right inside the aircraft's jack, but there's also a possibility that something screwy is going on inside the cable. Using an ohmmeter, you can test the cable when disconnected from everything and see if the tip is connected to anything. It should not be.

If the radio only keys once the audio source is plugged into the cable, the audio device is allowing current to flow between the tip and sleeve of the aircraft end of the cable, which are probably hooked to the tip and ring on the other end of the cable at the audio device.

If the latter, you may need a capacitor in-line to block the DC trying to flow, or a 1:1 audio transformer for the purists...

(The blocking capacitor creates an RC filter circuit with any upstream resistance in the cable, and can alter the quality of the audio a bit), depending on the resistance and capacitance values... not that it's going to matter much in a noisy aircraft.)

The other problem and also a likely culprit -- on the audio device end of the cable, you're dealing with a stereo connection where tip and ring are split into two (left and right, I forget which is which, but Google will find that), and shield which is ground.

You're taking two signals and feeding them to a mono jack. There's a few ways to handle that, but it could also be a source of where your pseudo-ground is showing up. Example, the iPod and iPhone actually use a four conductor plug, but that same jack will accept a standard 1/8" stereo jack which is only three conductor.

Your "sneak path" to ground from the aircraft tip might be something like that.

Google revealed this, which may help if you're into schematics and visuals...

http://www.aeroelectric.com/articles/micjack/micjack.html

The "extra ring" he talks about, found on many mic plugs, is called a "guard ring" and may or may not be grounded too (and/or causing your problem). I prefer the guard not to be grounded and floating instead, but have seen them both ways.
Click to expand...

Here's a question - are all intercom mic jacks wired the same?

In other words, would the one I bought work without transmitting externally if I plugged it into one of the rear seat pax intercom jacks?
 
I ended up going with an portable intercom that had a input feed for music. It worked well and only cut the music out on the pilots headset during any communications over the radio. I forget which one I have, but I know it was only like $40 - $50.
 
mikea said:
Hehe. Melting. There's more than just audio on the Apple earphone jacks. They also have a mic input.

I'd have to guess that intercom was leaking power to the audio input.



The PS Avionics Muse: http://www.ps-engineering.com/muse.shtml $349.95 list!!! Suuuuurrre. You can buy it for around $80.

Sent from my Macbook Pro
Click to expand...

Where can I buy this for $80?
 
So, what do you electronic types have to say about this claim made by the one that AS has:

The PSA0017C addresses the problem of attempting to use an aviation headset to listen to a portable music device while connected to the aircraft intercom. The 600 ohm aviation headset requires more power to drive than low-power portable music devices are capable of delivering.
Click to expand...

Could this possibly be the reason why a previous poster smoked 2 iMachines using a non-amplified system? (I have no idea...just askin'.)
 
I think the PS item just boosts it so it can be heard, something to do with the impedance, I believe. I'm certainly not one of the electrical gurus, however. ;)
 
Fearless Tower said:
Here's a question - are all intercom mic jacks wired the same?

In other words, would the one I bought work without transmitting externally if I plugged it into one of the rear seat pax intercom jacks?
Click to expand...

All the 4-place systems I've used did not include the rear seat vox in transmissions. The jacks themselves should be wired basically the same, although I'll bet the PTT part is dead-ended, and those voice circuits are probably not just available to the radios at the annunciator panel. It's logical... the rear-seaters may need to talk on the intercom, but they don't need to be heard outside the aircraft.

The rear-seat jacks would probably work, if you want to insert aux audio into the intercom for all to hear. And if the intercom has a switch to "ignore" rear-seaters, that would be a simple way to kill the music when you need to, without touching the player.
 
timwinters said:
So, what do you electronic types have to say about this claim made by the one that AS has:



Could this possibly be the reason why a previous poster smoked 2 iMachines using a non-amplified system? (I have no idea...just askin'.)
Click to expand...

Yup... either the devices' internal amp couldn't handle the total speaker impedance (too low), or the devices' "A/V" jack was not wired in simple unbalanced-stereo fashion, or the thing it was plugged into was not, and a short between positive and negative (which is also your ground leg in a 2-conductor circuit) was created. Give any amplifier a dead short to work with and it will kill itself trying to drive it, unless it has fancy protection circuitry (usually a thermal switch). I've had to swap out many commercial amps because some ignoramus had disabled a speaker by yanking the leads off it, and left them shorted together. The other speakers still on the chain might help raise the resistance a tad, but not enough, usually. Even if one leg (positive or negative) is shorted, as would be the case when somebody drives a screw through a speaker cable into steel framing (shorting it to the same ground as the amplifier), this can kill the amplifier eventually.

A short reads as zero impedance, an open as infinite. Basically, a short says "Gimme infinite current, damn your limit!!", and an open says "No, thanks, I'm good." Amp/speaker compatibility lies somewhere in between.

Very powerful amps can usually deal with a short-circuit situation as described above, but only if their available power is way in excess of what's needed to drive the group of speakers. But even then, it's not good for the amp in the long run.

Your typical portable music player has a simple, fairly wimpy amp. It might be OK with a higher impedance, but if it's too high the weakly amplified signal just won't be able to push the speakers. But give it an impedance lower than a set of earbuds, headphone speakers, or the line-level input circuit of an amp (home or car stereo, computer, docking station), and it will work too hard trying to provide more current than it has available.
 
Just realized I went down the wrong path in answering Tim's question about using a portable player to push high-impedance speakers... :rolleyes:

Because any amplifier has a maximum output impedance to deliver X volts at X amps at its output connector, technically connecting a higher-resistance speaker could hurt it over time. This is certainly true of tube amps; it's not good to leave them cranked up with no load on them. But it's much easier to trash an amp by connecting too low an impedance to it... I've never seen an active amp channel fail, even with its volume pot turned all the way up, because there was no load on it (infinite impedance), but I've seen many fail because of a short or speaker circuits with too low an impedance. And in my experience, if the impedance of the speakers is too high for the amp, it just won't drive them efficiently. Doesn't seem to hurt the amp.

Given all that, it seems unlikely that a pair of aviation headset speakers would harm an amp designed for smaller, but similar speakers, even if their impedance is higher than the output impedance of the amp. Connect an iPod to a very large 70-volt P.A> speaker, tapped at a high wattage, and the iPod might go up in smoke, I dunno. I do know that you wouldn't hear any music coming out! :D

However, if the audio signal being used is a line level signal, optimized for going to an amplifier or recording device (not directly to any kind of speaker), that might cause a problem... typically, that requires a fairly high impedance at the device it's going into, so maybe this was the case, and the headset speakers had too low an impedance. Most players, camcorders, laptops, and desktops only have one audio output, but maybe these had discreet "headphone" and "line" outputs. :dunno:
 
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