Sony TA-F 650 ESD Fully functional great sound on both channels with no noise or crackling.Tested on all inputs.Phono-Optical ...Optically phenomenally well preserved with minimal signs of use. Sony TA-F650ESD is an integrated stereo amplifier from the legendary ES (Esprit) series, produced around 1990. This model was innovative for its time as it included a built-in D/A converter (DAC), which allowed direct connection of digital sources such as CD players. Key features Digital section: It has 2 optical and 1 coaxial digital input, as well as 1 optical output. Power: Delivers 80W per channel into 8Ω, or up to 160-175W sine wave power into 4Ω. Construction: Uses a robust G-chassis (Gibraltar chassis) designed to minimize vibration and improve sound stability. Weight: The device is massively made and weighs about 11.8 - 12 kg.  Technical specifications Specification Details Frequency response 2 Hz to 200 kHz Distortion (THD) Extremely low, about 0.003% Damping factor 100 Inputs Phono (MM/MC), Tuner, CD, Tape 1 & 2, Aux Dimensions 430 x 150 x 390 mm User experiences and the market Users on the forums point out that the amp has a detailed and rich sound that doesn't tire after long listening, similar to the sound of the Harman/Kardon 665. It can be a bit picky about the speakers, but overall it provides excellent control.