On Tue, 27 May 2008 20:01:43 +0100 Simon Williams <simon@xxxxxxxxxxxxxxxxxxx> wrote: > Hello. > > I often run the PA system for my CU at uni. So far we've been using > jack-jack leads to connect guitars to the desk. However, my Dad has > recently started using jack-XLR leads at my home church and says that > it's much better. > > After a very long conversation and lots of googling (which incidentally > provides no info at all on the subject), I'm now completely confused. > > Are guitars mic or line or what? > > The rationale for using jack-XLR leads and connecting to the mic input > on the desk is that guitars have mics in them so they are mic level. > Apparently the battery unit in the guitar doesn't make it line level, > but I'm not convinced. > > The other thing I don't understand is that if that is the case, why do > people use DI boxes? A DI box takes a high impedance (line level - I > think) input and converts it to low impedance output (mic level). If the > guitar is mic level already then what's the point? > > Please, could someone shed some light on this because I'm now very confused. > > Thanks in advance. > Simon Hmmm, can of worms! A 'raw' guitar pickup gives typically 50-100mV and is generally regarded as 'high impedance' (that raises many points of contention in itself), but with built in amplification/processing could be a lot more. Line level is usually between 500mV and 1V. The nearest you get to a standard is 775mV in 600ohm, or 1mW. Microphones vary enormously depending on type, built-in amplification etc. and can be anywhere between 1-100mV. So as you can see, there is no simple answer. Welcome to the world of audio 'standards' :) -- Will J Godfrey http://www.musically.me.uk _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user