I have an Alesis RS300 Reference Amplifier that I have use for several years at shows. Running several mics and acoustic guitars through it. It has worked fine for this. I can also play record player, Reel-to-reel and cassettes through it with out issues. But, when I try to run anything digital through it such and my phone or computer the audio has a lofi distorted sound. If there is a solution to this problem I would appreciate it very much. Thanks.
are you going straight from your computer or Phone's 3.5mm jack, or are you using a DAC? I would recommend the latter.