10 | MiniMod 4 | User guide
11 : 4.Internal Signal Path Polarity
In order to increase the power’s supply energy storage
efficiency, signals coming from channel pairs 1-2 are polar-
ity reversed, one with respect to the other within the pair,
when entering the amplifier. This ensures a symmetrical use
of the voltage rails: if, for example, both channels 1 and 2
input signals are going through a peak at the same time,
channel 1’s energy will come from the positive voltage rails
while channel 2, whose polarity is reversed with respect to
channel 1, will be fed energy from the negative voltage rails.
In this manner, the power supply will work symmetrically,
with one channel driven by the positive rails and the other
by the symmetrical negative rails. Channel 2’s signal will be
polarity reversed once more to ensure that both channels
output with the same polarity as their corresponding input
signals.
For this reason it is very important not to invert the po-
larity of either channels before feeding them to the module.
A double polarity inversion (the first by the user inserting
the input signal and the other by the amplifier’s internal
circuitry) results in no inversion at all. If this were the case,
both channels would be weighting on only one side (positive
or negative) of the power supply’s voltage rails. This would
result in an inefficient use of the power supply’s energy.
Please pay special attention in using balanced inputs on
all measurement equipment (such as oscilloscope probes)
when you are bench testing.
11 : 5.Output Configuration
MiniMod 4 can be configured in 5 different output type
of connections:
4 x SE (Single Ended): 4 indipendent channels.
2 x BTL (Bridge Tied Load): Two couples of channels
bridged.
2 x SE + 1 x BTL: A couple of channel bridged while the
remaing two channels kept single ended.
2 x PTL (Parallel Tied Load); Two couple of channels
obtained by paralleling two channels of the module. This
configuration can be activated by short circuiting two pins
of output connector indicated on FIGURE X, it must be
done before switching on the module.
Activating the parallel mode on one of the output
connectors, implies setting up parallel mode on both
channel pairs. For safety reasons we suggest to apply the
parallel mode on both connectors.
1 x PBTL (Parallel Bridge Tied Load): A single channel
can be obtaned by bridging the PTL configuration.
GND
Parallel
-
+
-
+
GND
Parallel
+
-
+
-
CH1
CH3
CH2
CH4
Parallel
Parallel
4 x 150 W @ 4
Ω
GND
Parallel
-
+
-
+
GND
Parallel
+
-
+
-
CH1
CH3
CH2
CH4
Parallel
Parallel
2 x 300 W @ 8
Ω BTL
GND
Parallel
-
+
-
+
GND
Parallel
+
-
+
-
CH1
CH3
CH2
CH4
Parallel
Parallel
2 x 150 W @ 4
Ω
1 x 300 W @ 8
Ω BTL
GND
Parallel
-
+
-
+
GND
Parallel
+
-
+
-
CH1
CH3
CH2
CH4
Parallel
Parallel
2 x 300 W @ 2
Ω PTL
GND
Parallel
-
+
-
+
GND
Parallel
+
-
+
-
CH1
CH3
CH2
CH4
Parallel
Parallel
1 x 600 W @ 4
Ω PBTL
f
f
4 x 150 W @ 4 Ω SE
f
f
2 x 300 W @ 8 Ω BTL
f
f
2 x 150 W @ 4 Ω SE + 1 x 300 W @ 8 Ω PBTL
OUT 1
OUT 2
OUT 3
OUT 3
OUT 1+2
OUT 3+4
OUT 1
OUT 2
OUT 3+4
FIGURE 7: Internal signal path polar-
ity with example input signals. Both channels
1 and 2 are fed with the same sine signal.
first polarity
inversion
second polarity
inversion
Channel 1
input
Channel 2
input
Channel 1
output
Amp
Channel 2
output
1/2
3/4
first polarity
inversion
second polarity
inversion
Channel 1
input
Channel 2
input
Channel 1
output
Amp
Channel 2
output
1/2
3/4
1
2
3
4
