The GB100D is a fairly conventional fully complementary 100W rms into 8 ohm amplifier. The input stage uses 300MHz complementary differential input pairs with emitter degeneration for good differential linearity, with low noise current source tails. This is followed by the optimal, heatsunk 2SB1109C/2SD1609C 140MHz high gain fully complementary Vas stage feeding the 2 complementary pairs of  matched 2SJ162 /2SK1058 Audio MOSFETs in a conventional source follower configuration. These have the advantage of not needing elaborate thermal compensation, but the design includes source resistors for extra stability and current sharing.

Features of the design include:

  • RC filtered supplies to driver and input stages for improved high frequency PSRR
  • Low noise matched FET current sources for input differential tails
  • DC offset trim pot for nulling of DC offset eliminating DC from sensitive speaker types like ribbons
  • No need for thermal compensation components for simplicity
  • Maximised bandwidth lead compensation for best amplifier speed
  • Output coupling load isolation option for high C cables.
  • Same size and heatsink mounting as GB150D modules
  • Spade supply terminals optional  
  • Back to back input diff'l pairs for best thermal coupling esp for DC coupled option.
  • DC coupled option, allowing the removal of electrolytics from the direct signal path.


As an introductory offer, the first 10 sets (module kit pairs) are available for Au$200 + $10 postage
after which the price will be $125 + $10 per module kit.


 Power Output
100Wrms max into 4/8ohms
 Idle Power
 Freq. Response
 Input Impedance
 Slewing Rate
 Damping Factor
 Hum & Noise
100mm x 50mm x 30mm