Access virus os4 Manuale Utente

 

ACCESS VIRUS OS4

 

The First Filter

 

Now we will take a look at a com-
ponent of a synthesizer that is 
generally regarded as the most 
important functional unit as it 
enables drastic sound shaping 
measures: the filter - or in the case 
of the Virus, the two filters.

But first we will concentrate on 
just one of the two filters.

Locate the 

 

 pot (not to be 

confused with 

 

 2!) in the 

section labeled 

 

, directly 

above the section labeled 

 

. Rotate the pot to the left and 

right and note how the sound 

becomes muddier and clearer in 
response to the direction in which 
you turn the pot. (To ensure this 
effect and the following aural 
experiments are most pronounced, 
adjust the amplifier envelope so 
that the Virus generates a constant 
level while you hold a key down). 

This is how a low pass filter works: 
it suppresses, or in technical jar-
gon, attenuates the higher fre-
quencies in a signal and allows the 
lower frequencies through. Think 
of the 

 

 pot as a bouncer 

and the Virus as your pub. You can 
tell it which frequencies to let in 
and which frequencies to keep out. 
The frequencies above the so-
called cutoff or filter frequency are 
suppressed, those below it remain 
unaffected.Now locate the FILT 1 
MODE switch, which is also located 
in the 

 

 section. It enables 

you to select a filter operating 
mode from the four available 
options:

 

 

 

the low pass filter we have 

just discussed.