AD Ultrafidelity Vajra Power Amplifier

AD Ultrafidelity writes: “The Vajra Class AB precision stereo power amplifier provides supreme driving performance. The Vajra will bring out the very best of any speaker, allowing you to enjoy never-before experienced soundscapes. The Vajra, like the Padma, sports a fully CNC chassis of premium grade aluminium, ensuring an inert and stable base. Available in silver or black, its robust and sophisticated design ensures an efficient assembly and timeless appearance around an innovative design.”

The Vajra uses the highest quality components available. Each component is tested for it’s linearity. Linearity is a test of a component’s input to output relationship. Only components with perfect linearity are used to ensure the highest accuracy and musicality.


  • Class A for the first 15 Watts
  • 180W per Channel into 8 Ohms and 360W per Channel into 4 Ohms
  • Single ended and true balanced input stage using super-matched transistors to eliminate use of DC servo loop
  • World’s first known use of Power Supply Slit Foil Electrolytic Audio Capacitors
  • Large high-efficiency toroidal transformer (with DC Blocker) and large filtering capacitors
  • Built-in Mains Filter
  • Built-in DC Blocker
  • DC Coupled from input to output for highest possible accuracy
  • Fully electrically isolated from incoming power supply
  • Highest quality components used and tested for linearity to ensure highest accuracy
  • Class AB High current and voltage design
  • Large scale power meters
  • Speaker output protection  


  • Frequency Response (Hz) -3dB                                                                    0-100k
  • Power @ 8 Ohms 240VAC (W)                                                                             180
  • Power @ 4 Ohms 240VAC (W)                                                                             360
  • Gain (dB)                                                                                                                     27
  • Sensitivity (RMS)                                                                          2 V (BAL)  4 V (SE)
  • Input Impedance (Ohms)                                                        24K  (BAL)  12K  (SE)
  • Damping factor                                                                                                     >500
  • Noise Out                                                                     <-100dBu(0-22kHz, Rs=50R)
  • THD                                                                  0.001% at 1kHz (100kHz Bandwidth)
  • Dimensions (WxHxD mm):                                                               430 x 160 x 360