Vox AD120VTX - Manual (Page 6)

6
N
ERDY
I
MPEDANCE
I
NFORMATION
A
HEAD
The following is some information that you’ll find useful for hooking external cabi-
nets up your Valvetronix AD60VTX or AD120VTX combo. When you’re done with
this, you’ll be a smarter and better person! Plus you’ll know the correct way for
hooking up speaker cabinets in series.
In multiple speaker cabinet configurations, you will have to use a little mathematics
(Ohm’s law) in order to figure out the correct setting. Don’t worry though; it’s easier
than you might think! The formula below is for hooking up external cabinets up in
series, which is what we’re using here on the VTX amps.
Series (AD60VTX & AD120VTX)
In a series configuration, all you do is add the individual impedances of the cabi-
nets. For example, if you hook up two cabinets, where each is 8 Ohms (8 + 8), the
result is 16 Ohms. If one cab is 8 Ohms and the other is 4 Ohms, the total imped-
ance is 12 Ohms. There are no 12 Ohm settings on amps, so set your VTX amp to
16 Ohms.
R1 is the impedance of our first cabinet; R2 in the impedance of the second one
and R3 is the resulting impedance when they are hooked-up together.
R3 = 8 + 8 = 16 Ohms
Specifications
Number of amp types: 16
Number of effects:
Drive types: 10
Modulation types: 5
Delay types: 3
Reverb types: 3
Noise reduction: 1
Number of programs: 32 (8 bank x 4 channel)
Number of inputs:
AD60VTX
Top panel: 2 (High & Low)
Rear panel: 1 x Loop return
1 x Foot controller jack
AD120VTX
Top panel: 2 (High & Low)
Rear panel: 2 x Loop return
1 x Foot controller jack