12-inch, single speaker, YAMAHA. J-25 transistor amplifier, late 1970s, original price was 38,000 yen. Powerful 50W. Also, headphones can be used. There's no way you can ignore this amazing amplifier. This kind of catchphrase was used to sell it. Many people have written about this amplifier, and it has a good sound, a deeply rooted popular classic. This amplifier's speaker operation, each knob's functions include spring reverb, distortion, TREBLE, BASS, and VOLUME. When adjusting the knobs, there may occasionally be some crackling, but it can be resolved by slightly turning the knobs. This does not affect the performance. There is some popping noise, and there are areas with age-related deterioration. We appreciate your understanding. Thank you.