My Gateway product was the ADS L810 speakers in 1978. They were so good, I eventual had two pairs used. By this time I had the the other components of my system, Phillips GA-212 turntable (with Ortofon cartridge) purchased in 1974, SAE MK30 Preamp, Mk31B amplified, and my fantastic Sansui TU-9900 Tuner purchased in 1976!
I still have my originals ADS L810s (in storage) and my Sansui TU-9900 (in use). Up until I purchased the ADSs, I had mass produced Jensen speaker, but decent Superex studio headphones.
Maybe my true gateway product was the Phillips GA-212, I knew early on, the first thing I wanted to do was to be kind to my vinyl!