Solid State Hybrid
As opposed to discrete designs, the IA502 uses an IC to drive the power stages. The entire power amplifier circuitry for 2-channels are squeezed into a tiny TDA7250 10-pin IC. All that's required are four power darlingtons and some passive components to complete a high performance stereo amplifier. No biasing is required as the IC auto biases the output transistors. The IA502 lends itself well to multi-channel amplification. A 6~8 channel power amplifier can easily be constructed even by beginners. The TDA7250cfp This 2-channel hybrid IC is normally configured with TIP142/147 power darlingtons for its' output. For those who prefer to use power transistors instead, the TDA7250 can easily be converted. All that is required are a few transistors, 4 additional resistors and some rewiring. This conversion centers mainly on changing the output section to a Sziklai. Sziklai Output In our IA502 on the right, drivers Q1,Q2 are 2SC2238 and 2SA968, and outputs Q5,Q6 are 2SA1216 and 2SC292...