Yeah..Mixer will do, but..wait..what amp do you have? Guitar amp? Vocal goes to guitar amp will sound horrible. You better either get a keyboard amp or cheap PA system.
就算接return聽起來恐怕也是很怪 吉他amp的喇叭單體那種奇怪的響應本來就只適合吉他用而已 比較好的辦法還是像perrypan兄所說的,用keyboard amp 然後吉他掛個cab sim,這樣應該是唯一都可以兼顧的方案