Please agenda that the blueprint for this amp has been upgraded, and it is now recommended for connected aerial ability into 4 Ohms, but You will charge to go to extremes with the heatsink (fan cooling is awful recommended). It was originally advised for “light” alternate duty, acceptable for an equalised subwoofer arrangement (for archetype application the ELF assumption – see the Project
Page for the advice on this circuit). Where connected aerial ability is required, addition 4 achievement transistors are recommended, active in the aforementioned way as Q9, Q10, Q11 and Q12, and application 0.33 ohm emitter resistors.
Continuous ability into 8 ohms is about over 150W (250W for ±70V supplies), and it can be acclimated after added transistors at abounding ability into an 8 ohm amount all day, every day. The added transistors are alone bare if you appetite to do the aforementioned affair into 4 ohms at best accumulation voltage! Do not alike anticipate about application food over ±70V, and don’t bother allurement me if it is ok – it isn’t!
The ambit is credible in Figure 1, and it is a analytic accepted design. Connections are provided for the Internal SIM (published abroad on the Project Pages), and clarification is provided for RF aegis (R1, C2). The ascribe is via a 4.7uF bipolar cap, as this provides lots of capacitance in a baby size. Because of the impedance, little or no abasement of complete will be apparent. A polyester cap may be acclimated if you adopt – 1uF with the nominal 22k ascribe impedance will accord a -3dB abundance of 7.2Hz, which is absolutely low abundant for any sub.