features a built-in spring or digital reverb. Use the "Reverb" knob on each channel to decide how much effect is applied to that specific input, then use the Master Reverb knob to control the overall intensity. Troubleshooting Common Issues
is a 4-channel powered mixer head designed primarily for portability and ease of use in small venues, karaoke setups, and band practices. Key Technical Specifications audio choice qm4 manual link
While there isn't a single "official" manual link for the legacy Audio Choice QM4 features a built-in spring or digital reverb