Samson POWER AMPLIFERS PG3800 - Manual (Page 11)

Bridge and Parallel Modes
The PG Series provides a rear-panel switch that allows it to be used in either Stereo,
Bridge or Parallel mode. When this switch is placed in the “STEREO” (center) position,
the PG Series functions as a true stereo amplifier, where both of the two independent
amplifier channels (Channel 1 and Channel 2) can receive different input signals and
produce independent output signals. However, when the switch is placed in the
“Bridge” (right) position, the Channel 1 inputs signal is routed to both power ampli-
fiers bridged together, producing a single output signal with mono power ratings of
1000 watts at 8Ω and 2200 watts at 4Ω for the PG2200 and a 1800 watts at 8Ω and
3800 watts at 4Ω for the PG3800.
The illustration on the left shows how this works. In Bridge mode, the polarity
(phase) of the Channel 2 output signal is reversed relative to that of the Channel 1 out-
put signal. Both channels then process the same input signal, with the speaker load
connected so that power is derived from both channels. The effective voltage swing
seen by the load is thus doubled, so that the power output is multiplied by four.
When using the PG Series in Bridge mode, be sure to connect your loudspeaker as
shown in the illustrations on page 10 (and as silkscreened on the rear panel), with
the red (+) terminal of the Channel 1 output connected to the positive input of the
speaker and the red (+) terminal of the Channel 2 output connected to the negative
input of the speaker.
Do not use the black ground (-) output terminal of either channel (the speaker
load must “float” away from the amplifier chassis).
When the rear panel switch is placed in the left “PARALLEL” position, the PG Series
operates in a unique Parallel mode. In this mode, connect the input signal to Channel
1 only. This signal is then routed to both the Channel 1 and Channel 2 power ampli-
fiers, thus producing a dual mono output, with the following power ratings:
PG2200 2 x 280 Watts at 8Ω, 2 x 500 Watts at 4Ω and 2 x 1000 Watts at 2Ω
PG3800 2 x 560 Watts at 8Ω, 2 x 900 Watts at 4Ω and 2 x 1800 Watts at 2Ω
See pages 10- 11 in this manual for interconnection diagrams when using the PG
Series in Bridge or Parallel modes.
WARNING: Bridge mode is to be used only when the PG Series is connected to a
4 or 8 ohm speaker load. Use of Bridge mode with speaker loads of less than 4
ohms can result in severe damage to the unit due to excessive heat and current
limiting and will void your warranty!
INPUT
CHANNEL
1(+) OUTPUT
CHANNEL
2(+) OUTPUT
Bridge Mode
7