Advise on making a wireless guitar system

Steoob

hi, im bored lately and i thought i'd mess around with a set of wireless (RF) headphones and try and see if i can make a wireless guitar connection out of it. i could buy an actual wireless guitar system but that would be way too intelligent. so im just gonna buy me a set in argos soon for 50 quid and i have a fair idea of what to do, but i want to know if anyone else has tried to do this before, or can anyone offer me some advise. like for instance my brother told me its do-able, but there could be some problems with the ohms and stuff like that, hopefully we can have some fun experimenting with this, help would be so cool...

thanks
stevo

Steoob

cmon doesn't anyone has some input i can use??

Red Alert

ok, let's look at the input and the output.

The output of your guitar is going to be somewhere in the region of 1V into 10,000 Ohms. What the headphone's transmitter is expecting is roughly 250-500mV into 150 Ohms. You are going to need a transformer coupling network, remembering that transformers convert voltages proportional to their turns ratios and impedances in proportion to the square of the turns ratios. This done, you might need a potential divider to cut the voltage, maybe not. Remember to include this in your calculations for it.

I presume you want to plug the output of the receiver into a guitar amplifier as opposed to listening to it on the headphones. Therefore you will need to voltage/impedance match the output to the amp's input. A transformer will do the job here - you could probably get away with a standard DI box here if the amp's input gain is high enough.

A slightly more practical point is that the transmitter (which you are going to attach to your guitar) is not designed to run on batteries. While it might use a standard voltage e.g. 9V easily obtainable from a battery, the power draw might be quite high - so you might only get 1 hour from a set of batteries - an expensive proposition!

If you found some way of separating the headphone charger and batteries and reversing them you may be able to use the cordless re-charge system.

Capt'n Midnight

Advise on making a wireless guitar system

[can't resist]how are you going to play it if there are no strings ?[/]

Try a direct connection to see if it works - the input to the wireless system may have a higher impedence. If not then you could rig up a buffer amp using a op amp (gain = 1) if the gain is too high then use a potential divider on the output to keep component numbers down.

the wireless transmitter will use a fair bit of power - if you need a buffer amp check that both will run on the same voltage and use rechargable batteries.

Another option very LoFi would be to use cheap walkie talkies - lousy sound BUT the built in microphones might be usable and if no then they would constitiute a high impedence input (though expecting a much smaller voltage than the pickup) and I don't know what you do if they are capacitive mics

Steoob

hi, thanks for your help, alot of it will probably be used... i have done it but there is success and failures, the succes is that it does work and it was wored properly and a connection was made, but when i play the sound is so low, so then i just got an effect pedal which can also work as an amplifier so that you can plug headphones directly into it, so it was like this... Guitar-->cable-->pedal-->cable-->transmitter-->signal-->reciever-->cable-->amp

this is all fine and understandable, it does work fine but once the pedal is out of the equation then there is hardly any output. i understand obviously that you need an amplifier to amplify the sound but then why doesn't this work:
Guitar-->cable-->transmitter-->signal-->reciever-->cable-->amp

i mean all this transmitter to signal to reciever does is replace the cable right? so if it only replaces the cable then why doesn't it wait until it gets to the amp to amplify the sound. then of course i suppose i just realised that the sound needs to be loud enough for the transmitter to send it, yea that probably it.

Here's what me and my brother planned, we would buy a small pre-amp from maplins that amplifies low output sounds then go to the transmitter then the signal, would this work??? it makes logical sence, doesn't it?

thanks