MTX Audio Thunder404 Stereo Amplifier User Manual


 
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Input Panel Layout
POWER AMPLIFIER OWNER’S MANUAL
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1. RCA Input Jacks – These RCA input jacks are for use with source units that have RCA or Line Level
Outputs. An independent set of jacks are provided on the Thunder404 for front and rear stereo inputs. A
source unit with a minimum level of 200mV is required for proper operation. The use of high quality twisted
pair cables is recommended to decrease the possibility of radiated noise entering the system.
2. Input Select 2CH/4CH – This switch, found on the Thunder404, is used to match the amplifier’s input to
the source unit’s output so all four channels of the amplifier are driven. If your source unit has 2 outputs (left
and right) connect them to the amplifier’s front channel inputs, and place the input select switch in the 2CH
position. If your source unit has 4 outputs, (left front, left rear, right front, right rear) connect them to the ampli-
fier inputs and place the input select switch in the 4CH position. In the 4CH position, the fader on your source
unit will operate.
3. Speaker Level Inputs – This input will allow the amplifier to operate from source units with speaker-
level outputs. Output speaker leads from the source unit should be tied directly to the wire harness provided
with the amplifier.
Wire harness color codes:
Grey/Black = Source units right negative (-) White/Black = Source units left negative (-)
Solid Grey = Source units right positive (+) Solid White = Source units left positive (+)
With the Smart-Engage™ auto-turn circuit, a remote turn-on wire is not necessary when
connecting the speaker-level input wire harness to a high powered source unit. The amplifier will automati-
cally turn on when music is received.
4. RCA Output – These RCA outputs allow for a signal to be sent to other amplifiers in a daisy-chain con-
figuration. The RCA outputs on all Thunder amplifiers will send a full-range signal to additional amplifiers.
5. Gain Controls – These controls are used to match the input sensitivity of the amplifier to the particular
source unit that you are using. The controls are factory set to 1Vrms. Note that the Thunder404 has a sepa-
rate gain control for front and rear channels.
6. Crossover Select – This switch controls the type of crossover configuration that you desire. Thunder
2-channel amplifiers include a defeatable 18dB/Octave 85Hz crossover that is high pass/low pass or full range
selectable. The Thunder404 4-channel amplifier includes a defeatable 18dB/octave 85Hz crossover that is
high pass or full range for the front channels, and high pass, low pass or full range for the rear channels.