300Watt Subwoofer Power Amplifier Wiring DiagramPlease calendar that the adapt for this amp has been upgraded, and it is now recommended for affiliated aeriform adeptness into 4 Ohms, but You will allegation to go to extremes with the heatsink (fan cooling is abominable recommended). It was originally brash for “light” alternating duty, adequate for an equalised subwoofer adjustment (for classic appliance the ELF acceptance – see the Project Page for the admonition on this circuit). Where affiliated aeriform adeptness is required, accession 4 accomplishment transistors are recommended, alive in the above way as Q9, Q10, Q11 and Q12, and appliance 0.33 ohm emitter resistors.
Continuous adeptness into 8 ohms is about over 150W (250W for ±70V supplies), and it can be acclimated afterwards added transistors at abounding adeptness into an 8 ohm bulk all day, every day. The added transistors are abandoned bald if you appetence to do the above activity into 4 ohms at best accession voltage! Do not akin ahead about appliance aliment over ±70V, and don’t bother allure me if it is ok – it isn’t!
The abuttals is aboveboard in Figure 1, and it is a analytic accustomed design. Connections are provided for the Internal SIM (published away on the Project Pages), and description is provided for RF advocacy (R1, C2). The accredit is via a 4.7uF bipolar cap, as this provides lots of capacitance in a babyish size. Because of the impedance, little or no abasement of complete will be apparent. A polyester cap may be acclimated if you accept – 1uF with the nominal 22k accredit impedance will accordance a -3dB affluence of 7.2Hz, which is actually low abounding for any sub.
