This is the circuit of subwoofer amplifier. This amplifier can
produce an output of 100Watt. There are seven transistors including
four in the output stage. The transistors Q1 and Q2 form the
preamplifier stage. Transistors Q4 to Q7 form the output stage. Since
no ICs are used the circuit is very robust and can be easily assembled
on a general purpose PCB.
Skema rangkaian 100 watt sub-woofer amplifier
Note:
Use powered a +35V/-35V, 5A dual power supply.
All electrolytic capacitors must be rated 100V.
The transistor Q4 to Q7 must be fitted with heat sinks.
Transistor 2N3773 and 2N6609
Transistor 2N3773 (NPN) and (PNP) 2N6609 are PowerBase_ power
transistors designed for high power audio, disk head positioners and
other linear applications. These devices can also be used in power
switching circuits such as relay or solenoid drivers, DC?DC converters
or inverters.
Features Transistor 2N3773
Pb?Free Packages are Available
High Safe Operating Area (100% Tested) 150 W @ 100 V
Completely Characterized for Linear Operation
High DC Current Gain and Low Saturation Voltage
hFE = 15 (Min) @ 8.0 A, 4.0 V
VCE(sat) = 1.4 V (Max) @ IC = 8.0 A, IB = 0.8 A
For Low Distortion Complementary Designs
MAXIMUM RATINGS Transistor 2N3773
Collector ? Emitter Voltage: 140 Vdc
Collector ? Emitter Voltage: 160 Vdc
Collector ? Base Voltage:160 Vdc
Emitter ? Base Voltage: 7 Vdc
Collector Current Continuous: 16 Adc
Base Current Continuous 15 Adc
Total Power Dissipation : 150 Watt.
Jul 2003 OnSemi released a new range of transistors, designed
specifically for audio applications. These new transistors have been
tested in the P68, and give excellent results. As a result, all
previous recommendations for output transistors are superseded, and
the new transistors should be used.
The transistors are MJL4281A (NPN) and MJL4302A (PNP), and feature
high bandwidth, excellent safe operating area, high linearity and
high gain. Driver transistors are MJE15034 (NPN) and MJE15035 (PNP).
All devices are rated at 350V, with the power transistors having a
230W dissipation and the drivers are 50W.
Skema rangkaian amplif 300 watt
Note:
- The total DC is over 110V and can kill you.
- The power dissipated is such that great care is needed with transistor mounting..
- The amplifier circuit is NO SHORT CIRCUIT PROTECTION. The amp is
designed to be used within a subwoofer or other speaker enclosure, so
this has not been included. A short on the output will destroy the
amplifier.
- Transistor MJL4281A and MJL4302A are new most constructors will
find that these are not as easy to get as they should be. The
alternatives are MJL3281/ MJL1302 or MJL21193/ MJL21194.
All three driver transistors (Q4, 5 & 6)must be on a heatsink,
and D2 and D3 should be in good thermal contact with the driver
heatsink. Neglect to do this and the result will be thermal runaway,
and the amp will fail. For some reason, the last statement seems to
cause some people confusion – look at the photo below, and you will see
the small heatsink, 3 driver transistors, and a white “blob” (just to
the left of the electrolytic capacitor), which is the two diodes
pressed against the heatsink with thermal grease.