Product Details

Modern Tube Design for the 21st Century Listener

Bia 200 Select Class A Stereo Power Amp

100 Watts per channel with a 3 Position Bias Switch

Key Features

  • The Bias Select switch is engineered with 3 bias settings for 4 different output tube
  • Compatible with KT88, KT120, KT150 and KT170 output tubes
  • Bias Select switch is easy to use, change on the “Fly” so you can hear the difference
  • Auto Bias is safe, consistent and settings are always perfect
  • Class A power is fast for a more lively, immediate response to your music
  • 4, 8 & 16 Ohm taps gives you options for your speaker preference
  • Dual Mono gives you less cross talk and better stereo imaging
  • Choice of high quality gold plated Single Ended RCA or Balanced XLR connectors to suit your needs or cable preferences
  • True transformer differential balanced XLR inputs for the best noise rejection
  • Independent Left and Right ground switches on the XLR balanced inputs to eliminate ground loops and hums
  • No Negative Feedback design does not modify or compress the musical signal
  • Large custom Toroid is higher voltage for increased performance and lower noise
  • Global mains power supply can work all over the world
  • Provides plenty of gain for your system
  • Push-Pull/Ultra Linear circuit design provides lower distortion, more power, and a better performance out of your tubes
  • Low noise levels allow really dark black quiet musical passages
  • Non-inverting polarity retains the same phase as the input (so your trumpets blow and don’t suck)
  • Gold pin sockets are more reliable because gold doesn’t oxidize when it heat cycles
  • Matched quad KT150 output tubes retain the stereo balance and lower noise
  • Elegantly designed, heavy duty 14 &16 gauge zinc plated steel enclosure to accommodate the extensive grounding scheme
  • The optimized frequency response provides the best musical range to benefit the natural harmonic structure of the instruments
  • All fuses are easily accessible
  • Each unit is hand built “Made in the USA”

Specifications (based on KT150 tubes)


  • Class A
  • KT150 = 100 Watts per channel into 8 Ohms
  • 4 Ohm, 8 Ohm and 16 Ohm output taps
  • 10A, 7A and 5 Amp 6mm x 32mm Slow-blow speaker fuses for outputs
  • Eight 5-way binding posts
  • Non-inverting output polarity
  • Push-Pull Ultra-Linear design


Power rating for Auto Bias Select Switch Settings

Left Position:

  • KT88 = 60 Watts per channel,
  • KT120 = 60 Watts per channel
  • KT150 = 60 Watts per channel
  • KT170 = 60 Watts per channel

Middle switch position:

  • KT120 = 85 Watts per channel
  • KT150 = 85 Watts per channel
  • KT170 = 85 Watts per channel

Right switch position:

  • KT150 = 100 Watts per channel
  • KT170 = 100 Watts per channel



  • Transformer floating ground differential balanced XLR inputs
  • Left and right balanced inputs (pin 2 hot), impedance 10K Ohms
  • RCA single ended inputs Left and Right with impedance of 47K Ohms
  • Independent ground lift switches on left and right Balanced inputs
  • 5 Volts RMS input to reach rated output


Detailed Specs

  • Dual Mono
  • Auto bias
  • No negative feedback
  • Frequency response 20Hz to 30Khz ~ 3dB
  • Total Harmonic Distortion ~ 0.22% at 1W into 8 Ohms
  • Gain of 24dB
  • Noise level > 2mV -RMS into 8 Ohms with input shorted
  • 1% metal film resisters throughout
  • Polypropylene capacitors throughout the signal path


  • Custom Toroidal power transformer with global mains
  • 15 Amp IEC power mains connector
  • 120 Volts AC mains with 8 Amp 5mm x 20mm slow blow fuse
  • Optional factory installed 220V, 230V/240V 50/60Hz with 4-amp slow blow fuse
  • Power consumption at rated output 517 Watts
  • Front panel on/off switch with green LED indicator for high voltage and amber LED for low voltage


Active Components

  • Matched quad set of four (4) KT150’s vacuum tubes
  • Four (4) Gold pin ECC82 (12AU7) vacuum tubes
  • High quality gold plated ceramic sockets

Other Features

  • Each unit is made by hand
  • 50-hour factory burn in on all circuits and vacuum tubes
  • Dimensions 17″ W X 20″ D X 10″ H
  • Weight 64 (29Kg)
  • Shipping box = 27” x 27” x 13” (5 cm x 68.5 cm x 33 cm)
  • Shipping weight: 80 pounds (36 kg)
  • 16 and 14 gauge Zinc plated steel enclosure
  • Two year limited warranty
  • Six months warranty on Vacuum Tubes

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