source file: mills2.txt Date: Mon, 3 Mar 1997 03:25:44 -0800 Subject: Re: TUNING digest 1002 From: jeremy.tranter@virgin.net (jeremy.tranter@virgin.net) ------Quoted Message---------------- >Date: Sun, 2 Mar 1997 10:52:01 -0500 >From: Gary Morrison >To: "INTERNET:tuning@ella.mills.edu" >Subject: Re: Sympathetic Vibrations, etc >Message-ID: <199703021052_MC2-11F3-649D@compuserve.com> > Although I've only done so much with electric guitars, what I have done >with them suggests that most of the feedback from an electric guitar, the >strings aren't much involved at all. It comes from the guitar pickups >directly (electromagnetically) picking up the magnet of the speaker. >That's pretty apparent from the fact that you can damp the strings entirely >and it continues. ----------------Reply---------------- The strings ARE involved in the feedback from an electric guitar. Listen to electric guitar music - it is an important part of many styles. Controlling the energy coming back in will either give longer sustain or make a chosen pitch increace in volume. By pinching the string with the plectrum, second and above harmonics can be excited. Using a finger vibrato makes the fundamental a "moving target" so that only the higher harmonics get re energised by the feedback. The strings of an electric guitar will feedback by themselves if placed in the high levels of sound you get in front of a guitar amp. So will a bass guitar. A more resonant body will help that feedback because a large resonant body will feed more energy back into the strings. Semi-acoustic guitars are often used for this very reason. The squealing that occurs with some guitars which is nothing to do with the strings is microphony of the pickups. This is common with the early fender pickups and other badly constructed units. It is caused by loose windings in the coil being vibrated by the speaker, the emf induced is fed back to the amplifier further agitating the coils. It is a high pitch because the resonance of a little bit of 40swg copper wire is high. Dip your pickups in hot wax or get better ones! Jeremy Tranter Received: from ns.ezh.nl [137.174.112.59] by vbv40.ezh.nl with SMTP-OpenVMS via TCP/IP; Mon, 3 Mar 1997 13:04 +0100 Received: by ns.ezh.nl; (5.65v3.2/1.3/10May95) id AA02810; Mon, 3 Mar 1997 13:04:09 +0100 Received: from ella.mills.edu by ns (smtpxd); id XA02857 Received: from by ella.mills.edu via SMTP (940816.SGI.8.6.9/930416.SGI) id EAA19337; Mon, 3 Mar 1997 04:02:31 -0800 Date: Mon, 3 Mar 1997 04:02:31 -0800 Message-Id: <331AB859.211E@cavehill.dnet.co.uk> Errors-To: madole@mills.edu Reply-To: tuning@ella.mills.edu Originator: tuning@eartha.mills.edu Sender: tuning@ella.mills.edu