Once upon a time, audio receivers were made to listen to music, not for movies. The receiver was the heart of the stereo component system. It did not connect to a TV. Speakers were big. There were no subwoofers. A the prime directive was sound quality.
These three Yamaha receivers are Old School. No surround sound. Only a left and right amplifier. An input for phono. Knobs for bass and treble. No digital, no internet, no HDMI... but high quality sound with gutsy amplifiers and reasonble prices.
Built-in Phono Preamplifier. Since the CD took over and watching movies in surround sound was the driving force the last two decades, adding more features, more HDMIs, more digital, manufacturers took the phono input off their AV surround receivers to save money.
These three Yamaha Old School stereo receivers have a built-in phono input. The needle vibrates and creates a voltage... about three thousandths of a volt. When they manufacture a record, they deempahsize the bass and boost the treble, otherwise the bass would require thick grooves and it would only allow for 5 minutes per side. The treble is boosted so as to not mix with surface noise.
The built-in phono preamp takes the tiny voltage and boosts it to about 3/4ths of a volt, the same as a CD player or DVD puts out. Also RIAA equalization boosts the bass and lowers the treble to create a flat frequency response, to properly listen to a vinyl record album.
High Grade Parts. These Yamaha receivers are designed for music listening and high sound quality. Critical parts were chosen and tested... and critically listened to achieve that goal.
Discrete Output Transistors. Individual output transistors deliver more current, handle more heat, and control your loudspeakers more accurately. Discrete output transistors deliver more current, and current is really more important than watts. All expensive amps use discrete output transistors and so do these reasonably priced receivers.
Knobs and Buttons.There is good old fashioned knob to adjust the bass and another for the treble. Another is a variable Loudness adjustment that compensates for human hearing at lower listeniing volumes. There is a Balance knob also.
iPod Dock. There is one modern feature of these receivers, a separate connector on the back for an iPod dock. This dock has its own power supply for bettre sound. They do have remote controls.