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| Thread ID: 39511 | 2003-11-09 01:52:00 | Off Topic: Need help from electronics expert | somebody (208) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 190231 | 2003-11-09 01:52:00 | I know this has absolutely nothing to do with computers, but I need some help from an electronics expert. What I intend to build is a small device, powered by either a 9v battery or one of those cheap DSE transformers. It needs to basically take a mic-level input (needs adjustable gain control), and then to amplify it enough to power up to 6 headphones (in parallel). Mono is preferred, as it would require less circuitry. Currently I use an old professional mixer, however that takes up too much space, and there are much better things which it could be used for. Does anyone know where there might be circuit diagrams I could obtain to do something like this? I am have enough electronics knowledge to understand circuit diagrams, and to build things, but not to design them. :D |
somebody (208) | ||
| 190232 | 2003-11-09 01:57:00 | Have a look at DSE's or Jaycar's kits. They both have simple 1W or so amplifiers. You'll find that a stereo might not be much more complicated than a mono, with the IC amplifier chips used. You can put your creativity to paralleling up the output sockets. ;-) | Graham L (2) | ||
| 190233 | 2003-11-09 02:00:00 | Thanks Graham. I'll definetely have a look. What I also need to add is something to split the output, and then using some circuitry to reduce one of the output signals down to a mic-level signal. I also need to allow for an extra line-level input which needs to go through the same amp. I suppose I could adapt one of DSE's kits though. |
somebody (208) | ||
| 190234 | 2003-11-09 02:06:00 | I am sure that either DSE or Jaycar will have off-the-shelf kitsets to do what you want. A brief look suggests DSE have several pre-amp kits capable of being driven by a microphone. A number of low power audio amp kits are also available to drive the headphones. A suggestion, if you want remote headphones driven from a single mic, have you looked at the mini stereo transmitter kit K5009 ? Drive it with a preamp and use ordinary walkman type FM radios as the remote headphone receivers. Select an unused part of the FM band and range should be 50 metres or more. |
godfather (25) | ||
| 190235 | 2003-11-09 02:48:00 | Good idea. What I am actually building is a permanant powering device for the wired comm system I was asking about on this forum about 6 months ago. I have devised a way of making it work with 4 headsets (typical ones designed for computers), however that requires the use of an expensive audio-mixer. What I was hoping for was basically a system which could cater for 6 always-on headsets, so everyone could talk to everyone. The maximum distance between a headset and the "base unit" would be about 40m. Would a DSE Kit such as: www.dse.co.nz do the trick? I currently already have a Electret-mic powering device which works. |
somebody (208) | ||
| 190236 | 2003-11-09 03:24:00 | That amp would have plenty of power to drive the headphones (suggest about 22 ohm resistor in series with each headphone to stop swamping the amp) You will still need a pre-amp though, as that amp kitset will likely have a "line in" level, not a mic in level. Unless your electret powering device already does that. The walkman solution is only one way, so not suited. Pity as its a cheap solution. |
godfather (25) | ||
| 190237 | 2003-11-09 05:14:00 | Lots of good suggestions there Somebody. I wonder if your requirements are clear. You firstly asked for a system to "Take A mic input, to power up to 6 headphones" Then later you say it needs to cater for 6 headsets "so everyone can TALK to everyone" Are you saying that the device should not only output to 6 headphones, but also input the 6 headsets mics, so everyone can TALK to everyone? I guess it could be done, but it's getting more complicated. Good luck. |
Bazza (407) | ||
| 190238 | 2003-11-09 21:10:00 | Sorry . I should have made my initial post clearer . This is what I intend to do: I need to connect 6 headsets (the ones you get a computer stores) together in such a way, that 6 different people, up to 30m way from the "base unit" (for powering the headsets), can all talk to each other . At the moment I am using a simple setup with 4 headsets wired together in parallell, so all the "headphone" parts are connected to the left channel output of a mixer, and all the "mics" are connected through an electret-mic-powering circuit (in parallell) then connected to a mic-input on a mixer . What I want to do is eliminate having to use the mixer altogether (very expensive piece of equipment to be using for a comm system), and add another 2 headsets to the system to make a total of 6 . I am only guessing (I don't have very advanced electroncs knowledge) that I can add another 2 headsets in parallel like the other 4, and it should still work . I will also need to somehow add a PRS radio to that (Uniden Uh-089), so that people on the Radios can hear what people on the headsets are saying, and people on the headsets can hear what the people on the radios are hearing . I will need to somehow add a line-level-input onto whatever powering device I use, and also an attenuator or similar device so I can plug an output from the headset system into the mic-in on the Uniden Uh-089 . Everything can be done in Mono . I know there are professional systems out there (such as the Technical Projects ones - quoted for $4000), however the sheer cost of them has forced me to try and build a system up myself . As this could be quite a complicated design, I would probably need several DSE kits or similar to make it work properly, as well as having to add some of my own circuitry to it as well . If anyone has any suggestions to offer me, or comments saying that what I am doing/planning to do will blow something up/is not going to work, please let me know . |
somebody (208) | ||
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