This is a rare item that is not widely available. Reference material (manual can also be downloaded. It's in English, so please use a translation app, etc.) → Studio Channel – PreSonus https://share.google/Y0isyrifyxNSTF2bM I purchased it new and used it a few times for home recording. I probably threw away the manual and box (lol), so it's just the main unit and power adapter. The output from just an sm58 microphone wasn't enough, so I got this. It was very easy to use and very effective, but I'm not doing home recording anymore, so I'm selling it. The Studio Channel is a professional-grade channel strip suitable for use in professional studios and project studios, integrating a 12AX7/ECC83 Class A vacuum tube preamp, a VCA-based compressor, and a 3-band parametric equalizer. Excellent for use with all types of microphones, instruments, keyboards, and synthesizers, the Studio Channel has the power and flexibility to achieve the ideal sound, whether it's sweet vocals, extremely clear acoustic guitars, powerful and solid bass, dynamic piano, clear snare drums, punchy bass, or huge MPC tracks. Please refrain from purchasing if you are sensitive to returns, refunds, and complaints, or if you are slow to make payments, provide feedback, or respond to necessary communications.