There is no currently hosted official PDF manual on a primary manufacturer site, as the product is often sold through secondary markets like eBay and Reverb . However, the core operation and specifications are well-documented: : SoundTech Audio Choice QM4. Key Functionality : 100-watt powered 4-channel mixer head.
The QM4 system is valued for its "rugged and easy to operate" design. Specification 100 Watts RMS @ 4 Ohms Mixer Channels 4 Channels with independent Gain, Tone, and Reverb Inputs Combination 1/4" and XLR ports per channel Master Controls 3-Band EQ, Master Reverb, and Level controls Outputs EFX Loop, Line Out, and Footswitch option Speakers Two 10" enclosures with performance-rated horn tweeters Weight Mixer head: ~9.5 to 20.5 lbs; Speakers: ~22 lbs each Setup and Operation Guide audio choice qm4 manual link
While there isn't a single "official" manual link for the legacy Audio Choice QM4 There is no currently hosted official PDF manual