ST-140

About the ST-140

The B&K ST-140 is a solid-state stereo power amplifier known for its detailed, beautifully sweet and airy top end, remarkable depth and soundstage spread, and authoritative low-frequency performance. Although rated at 105 watts per channel into 8 ohms, it delivers the dynamic punch of a more powerful amplifier, though it does not match the sheer power of a 200-watt amplifier. It features a frequency response of 5Hz to 45kHz, a damping factor of 100 at 50Hz, and a low total harmonic distortion (THD) of 0.09%. The amplifier has an input sensitivity of 1.2V (unbalanced RCA) and an input impedance of 24k ohms. It weighs 11 kg and measures 43.5 x 42 x 16 cm. The ST-140 was highly regarded for its sound quality and value, especially at its original price of in the mid-1980s. It was praised for being a cost-effective amplifier choice for audiophiles on a budget, with a sound that is balanced and tolerable on various speaker types including dynamic and electrostatic systems. There were multiple versions of the ST-140, with power ratings of 70W and 105W per channel, some featuring toroidal transformers and different front panel designs. The amplifier was manufactured in the USA by B&K Components Ltd., based in Buffalo, New York.