General: Headsets

At school we have a keyboard system using the Roland TL-16 (a glorified mixer which is handy for teaching) and every station has a stereo headset with mono microphone. The headsets are all worn out and we want to replace them, but unfortunately to replace them with exactly the same model is outrageously expensive (over £30 each - and they're not good quality). They use 1/4" jacks but we have the adaptors for 3.5mm jacks.

I picked up a couple of headsets - a Creative one and a Plantronics one, to see if they were any better (they were both cheaper). Unfortunately we can't get the microphones working on either, and it seems to be because they have a stereo jack on the end - they have mono microphones but make it stereo by feeding the same signal to left and right but with opposite polarity. Obviously if you then plug this into a mono jack the two signals cancel each other out and it doesn't work.

Any suggestions as to how either to make it work, or headsets with a mono plug on the end of the microphone jack, which are cheap, but sufficiently sturdy to withstand schoolchildren?

Lolly, the other possibilities are the newer microphones are "electret" types and require a small voltage on the line wire to make them work and non standard connections on Jack plugs and sockets, especially between 3.5mm and 6mm plugs and sockets.

you need to check what part of the old plug does what. A signal generator will soon find the rings for left and right earphones and what part of the plug is earth. the mic is what ever is left over. There were many variations on the 6mm jacks, the 3.5mm verity have been standardised for many years. Some 6mm plugs have three rings and a tip connection, some have four rings plus tip. this way the mic had a separate earth. What are your ones like?

If you find the difference is the cause, may I suggest a great little job for someone who's is good with a soldering iron and change all the 3.5 plugs to 6mm of the type you are already using wired in the same way. I do suspect the first reason is why the mic part doesn't work. I hope that is some help.

Mmm, two separate leads on the headsets, which ones, old or new. Does the Roland mixer thingy have separate inputs/outputs as well? The old mics could be moving coil/dynamic types, so impedance matching could be a problem with some types of mic apart from the feed voltage.

Would it be possible to cobble the old mic on to a new pair of reasonably priced headphones? Or maybe some way of turning the old mics in to desk mount types. Just a suggestion.

That's a shame, I was assuming the earphones were wearing out not the mics. As the Roland has two separate jacks, maybe some chepish desk mics may prove more durable. Although it is nice to have the two integrated.

Headsets with dynamic microphones tend to be made for aviation use because of their excellent reliability and anything to do with aircraft is usually expensive!

I wish you luck in finding what you want at a sensible price.