It's a cheap Parts Express amplifier and I posted the model number and other details earlier in this thread. Replacing or modifying the power supply to send more power to the audio amplifier would probably require modifying the amplifier. Have you tried using the speakers that other people are using in the Blast City? I like how my Blast City sounds but if I were to do it again I would try an easier solution first.What Amp are you using? Did you ever try to just replace the blast city power supply with a different psu and keep current amp.