BugBrand UTL3 User manual

UTL3 – Dual VCA
Rev1 – Jan2010
Overview:
The UTL3 features two independent Voltage
Controlled A plifiers (VCAs) each with
response switchable fro Linear to
Exponential.
Controls:
1. Audio Input1 – DC-coupled input for
the signal to be processed by VCA1
(typical +/-5v).
2. Control CV1 – A plitude Modulation
input for VCA1 with depth control
(Mod1). Requires a 10v PtoP signal for
full range.
3. Audio Input2 – DC-coupled input for
the signal to be processed by VCA2
(typical +/-5v).
4. Control CV2 – A plitude Modulation
input for VCA2 with depth control
(Mod2). Requires a 10v PtoP signal for
full range.
5. VCA1 Response – Switchable fro
Linear to Exponential response.
6 VCA Output1
7. VCA1 Initial Control – Manual
A plification control for VCA1 fro
fully closed to fully open (unity gain).
8. Amplitude Modulation Depth 1 – To
adjust the depth of odulation fro
the CV1 input.
9. VCA2 Initial Control – Manual A plification control for VCA2 fro fully closed to fully
open (unity gain).
10. Amplitude Modulation Depth 2 – To adjust the depth of odulation fro the CV2
input.
11. VCA2 Response – Switchable fro Linear to Exponential response.
12. VCA Output2
Notes
•The odulation inputs require a 10v Peak-to-Peak signal for full range (lower voltage
ranges ust be a plified before use). Be aware of the type of odulation signal being
applied and how this will affect the Initial control setting – for bipolar +/-5v control
signals the Initial control should generally be set to about half-way for full deflection,
while for unipolar 0-10v control signals the Initial control should be set to zero (In both
cases the Mod control depth should be set to full).
Adjustments
•Each VCA has an Offset Tri er to null any DC offset (setup before shipping). There
are two possible ways to adjust the setting – I) apply a +/-5v square-wave odulation
signal to the CV input, turn the Initial control to idway and the Mod control to full.
Leave the Input socket disconnected. When correctly tri ed there should be ini al

control feed-through, so slowly adjust the respective tri er and listen for the control
signal feed-through beco ing less and less. 2) use a volt- eter to easure the output
offset and tri to 0v. Leave the Input disconnected (or connect to ground/0v) and do
not apply a odulation signal. Turn the Initial control to full and the Mod control to
zero. Slowly adjust the respective tri er until the output easures exactly 0v.
Specifications
Current Draw: +ve 10 A, -ve 10 A ( ax)
Module Width: 1 Frac-Width (1.5”)