The full digital 4-channel mixer, the DJM-800! It's a standard, a classic, you'll find it in large clubs and the like. The sound quality is, as expected from PIONEER! The two types of effects are also superb. This is OITARECORD Minoru! This mixer needs no introduction, but I'll explain it anyway! The DJM-800, a 4-channel high-quality mixer that's a staple in clubs! You'll find it in a lot of different clubs. Regarding the effects, it has the usual effects, of course, but it also adds a new "Sound Color FX" to all channels independently. Pay attention to this Sound Color FX. It's incredibly useful!!!! The knob labeled COLOR, located below the EQ knob. This knob adjusts the intensity of the Sound Color FX. And the four blue buttons on the left select the effect. This Sound Color FX has four types: HARMONIC, SWEEP, CRUSH, and FILTER, and it's super easy to use. First, select the effect you want to use from the four buttons and press the button, then turn the COLOR knob of the channel you want to apply the effect to, to adjust the intensity! With this, you can apply incredibly precise effects. The "FILTER" effect is popular with house, techno, and trance DJs, and it's included in both the conventional effects and the Sound Color FX, so you might wonder, "What's the difference?" But this is where it gets really interesting, in my opinion. Turning the COLOR knob to the left makes the sound muffled. Turning it to the right makes the sound brighter. So, you can muffle the sound through '1, 2, 3, 4, 5, 6,' and then suddenly brighten it at the end with '7, 8.' By using it precisely, you can create DJ-specific effects that you've never had before, and you can fully express your individuality. I think it's in good condition for its age. All switch buttons have been tested and are working. The effect buttons are prone to failure, so they have been replaced with new ones. The faders have been maintained. There is no noise or crackling on the faders or knobs. Judging by the knobs, it seems to have been used infrequently. It's been serviced, so you can use it for a long time.