Can a DAC sort out a flat\cold amp?

My pc is connected to an external sound card (scarlett 2i4 by focusrite). I bought the Yamaha a-s1200 & am really disappointed at the brightness & the lack of bass to the extend I prefer listening to my portable JBL boombox. I'm in no position to sell or trade this amplifier so I thought a DAC with eq may help the predicament. Since auditioning my equipment is not an option in my country I have no choice but to buy something purely on recommendations. I also thought about replacing the speakers but since I listen to soundcloud & youtube i really think upscaling & eq will be much more cost effective option in sorting out this issue & may give me the confidence to try a much more expensive speaker option. what would you recommend?