125 Watts / 8 ohms
200 Watts / 4 ohms

by michael chua

c200 module


The c200 is the result of numerous diyers' request for a basic discrete power amplifier. As such, this amplifier is specially designed to meet the following:

  • fairly high power output
  • easy to construct
  • use common components
  • no oscillations
  • have current limit protection
  • above average hifi performance
  • bridgeable for HT subs
  • rugged enough for party use

c200 specifications


Power Output

Output of the c200 into 8 ohms before clip is 125 Watts. When loaded to 4 ohms, the output is increased to 200 Watts. With 2 channels operating in bridged mode, power output is a respectable 400 watts into 8 ohms.

Output Transistors

For easy procurement, very common transistors have been chosen for the c200. The power transistors comprise of 4 pieces of MJ15003 and MJ15004. Though "slow" (fT=2MHz) by today's standards, these transistors are easily available, reasonably priced, has sufficient power rating and the necessary SOA for audio. For those who prefer to use 2N3055 and MJ2955, the c70 model, with 70 Watts/RMS output is available.

Vas & Drivers

TIP29C/30C are used for these stages. Though equally slow (fT=3MHz), they are chosen based on availability and cost.

Input Differential

2N5551 is used for input. Again, this is a common part number with properties suitable for audio.

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