dixiechicken
Friday 26 January 2007 à 12:55
QUOTE (Nicola Bloom @ Wed 24 Jan 2007, 21:40)
Hello there.
..........
Can someone suggest how I can get a less buzzy sound on my tracks.
.....
... removed text
If so, can you recommend cheap pre-amp budget £50
Thanks
Nicola (ibook G4 1.2 OX10.3.9)
Hi Nicola!
Crashcourse on signal levels and electric impedance matching:
1) Impedance is frequency dependent resistance the the elctric current flowing through
a cable, loudspeakercoil, electronics etc.
OK:
A typical Vocal mic (Shure-58 lets say) vill procduce a couple of millivolts on the pins when you
shout at it. The impedance at the output pins will typically be around 150 - 200 Ohms.
The microphone output should then be connected to a amplifier/mixer/linebox etc. with an
input impedance of lets say 10KOhms - 50KOhms.
The amp-imput should accept about 5-10 millivolts as maximun value to produce the appropriate volume, effect-watts or volts at the amp output-pins.
Whats appropriate depends, a preamp may accept 5millivolts at the input and pruduce 775millivolts at the output.
A typical poweramplifier will need 775 millivolts at the input to procuce full effekt power (number of watts) to the connected loudspeakers.
Warning you CANNOT EVER reverse this signalchain.
IF your mic has an output-impedance of 50KOhms ( unusual - but anyway ) and you connect a
200 Ohms input - you will in practice almost short out the hot pin carrying the current - with
respect to the ground. ( your reference zero point ).
Result is heavy signal loss and a lot of extra hiss & hum.
It's possible to totally degrade the signal you actually want to record, into uselessness.
Cheers: Dixiechicken