Biscuit needs a 9 volts power supply with an AC output, and not DC like the standard power supply adapters.
The specs of the Biscuit’s power adapter are :
Out : 9 volts AC output – 0.5 Amps (500 mA) or more – 2.1 mm round plug
You can buy this kind of power adapter in electronic stores or on eBay.
We can also sell you one. You can send us an email for pricing with shipping costs.