Audio Research S-100
Stereo Power Amplifier
The Audio Research founder Bill Johnson demanded that solid state designs never fail to engage the listener. In this way, they were to follow the north star of their Reference Tube Amplifiers. Fulfilling this demand, the S-100 solid state amplifier defies the customary limitations to musical expression and purity that otherwise plague this class of product.
Like the S-200, the S-100 is a pure Class A/B design, on a dual mono platform. Despite being scaled down from its larger sibling, the S-100 is conservatively rated and doubles into 4 ohms via dual toroidal transformers and a fully balanced stereo circuit. Once again, bipolar transistors were chosen over MOSFETs for their purity, transparency, and better dynamics.
Beginning with a beautifully machined aluminium chassis in either black or silver anodised finish, S-series amplifiers nod to the classic Audio Research design character, but from a sleeker and more modern angle, with custom machined heat sinks and no visible fasteners from the front or top.
The S-100 and S-200 amplifiers represent the Audio Research latest and most advanced entries into solid-state amplifier design. After all the measurements and bench testing, every product is proofed by ear, as it has been for decades. All of their S Series amplifiers are produced in our Minnesota facility alongside their Reference Tube Amplifiers.
Audio Research S-100 Specifications
Power Output – 100 Watts channel into 8 ohms, 200 Watts channel into 4 ohms
THD – <.1% from 0.25W to rated output into 8 ohms @ 1Khz
Input Sensitivity – 1.4V RMS Balanced for rated output
Input Impedance – 100kΩ Balanced or Single-Ended
Gain – 26dB
Input Sensitivity – 1.8VRMS for rated output
Noise – <60µV output
Frequency Response – +/- 0.1db from 20Hz to 20KHz
Damping Factor – ?? from 20Hz to 1KHz
Power Requirements – @120VAC, Standby: 0.25W. On, idle: 48W, Rated output: 475W
Dimensions – Width 19″ (48.26 cm), Height 7” (17.78 cm), Depth 17.5” (44.45 cm)
Weight: 41lbs (19kg) Net, 63lbs (28.5kg) Shipping
The company occupies a 48,000 square-foot, technically-advanced production plant and administrative headquarters in Maple Grove, Minnesota, where approximately 50 technical, assembly and support staff guide the product line from concept to finished goods. 
