Not sure but how does it compare to a Firefly amp that you could build for around 100 bucks. Ted Webber has a power supply transformer for 12 bucks and an output transformer for 8 bucks you can buy the blank PCB for 20 bucks. With the Firefly amp being simple tube circuits. The Nano amp must have a 200 volt switching power supply in that little box so DIY repair is not going to be easy.