PDA

View Full Version : [RUBRICA] La storia del rock, N°2


gigio2005
14-05-2008, 11:23
BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST
BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST
BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST BETA TEST

Il primo numero non ha suscitato molto interesse, noto :D

http://www.hwupgrade.it/forum/showthread.php?t=1735077


vabbe'...ci riprovo...


(1957) - Il primo pickup humbucker

Nel 1957 Seth E. Lover (01/01/1910 Kalamazoo, Michigan – 31/01/1997 Garden Grove, California) costruisce per la GIBSON il primo pickup in grado di eliminare rumori e interferenze generati dai cavi elettrici. (US PATENT: N° 2896491)

Qui una sintetica descrizione del funzionamento:

In any magnetic pickup, a vibrating soft-magnetic guitar string induces an alternating current in its coil(s). However, magnetic coils also make excellent antennas and are therefore sensitive to electromagnetic interference caused by mains wiring (mains hum) and electrical appliances like transformers, motors, and computer screens. Guitar pickups pick up this noise, which can be quite audible, sounding like a constant hum or buzz.

A humbucker has two coils with opposing windings and polarities. The string motion induces current in both coils in the same direction. Electromagnetic interference, on the other hand, induces current in opposing directions in each coil because of the reversed winding and polarity. When the signals from both pickups are summed together, the noise is cancelled due to destructive interference, while the actual signal is increased due to constructive interference, thus dramatically improving the signal-to-noise ratio. This technique is called common-mode rejection by electrical engineers, and is also used in balanced lines in audio recording.

http://en.wikipedia.org/wiki/Humbucker

Fabiaccio
14-05-2008, 12:59
lo vedi che quando ti ci metti d'impegno riesci a fare anche un bel lavoro?
continua così ;)