JBL Power supply / Input –
Crossover – Power Amplifier _ Schematic (Circuit Diagram)
SPECIFICATIONS
Number of
Channels . . . . . . . . … 1
4 Ohms . . .
. . . . . . . . . . . . . . . …… 600W
2 Ohms . . .
. . . . . . . . . . . . . . ………1200W
T.H.D. @ 4
Ohms rated Power . . 0.10%
Frequency
Response . . . . . . . . . . 10Hz ~ 320 Hz
Signal to
noise Ratio . . . . . . . . . . . >100dB
Maximum
Current Draw . …………114A
Fuse size. .
. . . . . . . . . . . . . ………… 40A x 3
Input
Sensitivity. . …….. . . . . . . . .250mV ~ 4V
Minimum
Speaker Impedance…1 ohm
External
Dimensions
Length . . .
. . . . . . . . . ……………….14 13/16 (376mm)
Width . . .
. . . . . . . . . . . . . . . . . . . 10 3/16 (274mm)
Depth . . .
. . . . . . . . . . . . . . . . . . . 2 11/16 (68mm)
Under
certain large signal conditions during intense bass passages, the unit will go
into protection. These amplifiers are behaving as designed. As the unit is
driven into hard clipping, the protection circuit found in BP Series amps was
engineered to protect your loudspeakers from being destroyed by a severely
clipped output signal. This
can be remedied easily by turning the volume down somewhat on your music
source. In the event you receive a BP
series amplifier with the complaint: “Under a large signal input, with music
that is composed of high-level bass, the amplifier mutes for 2-3 seconds, and
then returns to normal operation”, the following modification will effectively
increase the amount of clipping that is allowed to occur before the protection
circuit engages by increasing the threshold at which the amplifier mutes - for the
benefit of customers who use the amps in SPL competition, or for customers who
insist on driving the amplifiers into this potentially hazardous zone.
1 Turn the amplifier upside-down and remove the
Phillips screws holding the bottom cover on.
2 Locate and change R510 from 47K to 4.7K ohms
1/5W (JBL part# RE212047200).
3 Locate and change R511 from 22K to 2.2K ohms
1/4W (JBL part# QAF0450-222).
4 If it is not already present, add new part -
4.7uf 50v electrolytic capacitor (JLB part# EC070114760) in parallel with R511.
Polarity: The negative side of the Capacitor must be connected to the junction
of R510/R511, which can be discovered with an ohmmeter.
NOTE: Using
the correct soldering techniques, you should be able to make these changes from
the top of the PCB without its removal.
5) Replace
bottom cover; test amplifier.
POWER SUPPLY SCHEMATIC
INPUT - CROSSOVER - POWER AMP
