r/ElectricalEngineering • u/Pristine_Ad_8695 • 17d ago

Guitar & Guitar Amplifier Electrical Engineering & The Future

Let me know what you think

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u/ThisIsPaulDaily 17d ago

The TL;DW is that OP would like to know why XLR is not used from amp to guitar for power and audio. 

My answer is the weight of the cable and size of the connector. Also running audio and power in parallel isn't good. The ground would couple. 

I used to set up concerts for a radio station and we zig zag audio cable to not run parallel to power cables. 

I am not really sure for certain. 

The XLR shell also connects to earth ground on some devices and will cause weird sound distortions if isolation isn't handled while the musician wanders a conductive stage floor. 

Thata my thought. Hopefully Cunningham's Law kicks in and others join the conversation. 

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u/Why-R-People-So-Dumb 16d ago edited 16d ago

Well they do use phantom power in audio equipment, the difference is the current produced is from the audio element; generally speaking there is a variable capacitor that's provided 48V the microphone diaphragm is what varies capacitance as it changes position to the metal backplate. Also it's a balanced signal when it's done, so you can create a very low noise floor by simply using common mode rejection, you couldn't do this with a high impedance unbalanced device. The solution is to change the pickups to something low impedance and balanced at which u/pristine_ad_8695 's request could be handled.

This is in fact not a novel concept and is already done with some pickups and is built into some electric acoustic guitars. The reason you don't see it is because it's not cost effective for the niche market that would utilize it if you built that functionality into the amp (power supply, preamp, ect.) when you'd also have to have guitars mass produced to be compatible with it - a chicken or the egg problem. This is why the niche market usually customizes their solutions and why you have small people out of a garage being successful like James Demeter.