I bought a budget headphone amplifier Objective 2 (Mayflower manufactured), yet just realized that even power supply has a North American plug, it expects 220 V 50Hz (european voltage). I cannot return due Massdrop sales policy. Apparently compatible/recommended power supply ( 120 to 13-20 AC with 2.1 barrel plug) are not so expensive per se (<15$), yet rare and expensive to deliver (about 30 CAN). The amplifier also supposed to work from two 9V rechargeable batteries (I guess about $20), though I do not see where to insert them, probably need disassembly the device. I also have a 220 -> 110 V converter but not wise versa. So is there reasonable way to make it work besides ordering new power supply from Mayflower? For some reason unit is not expected to work with normal AC/DC converter, and requires AC-AC power supply.
The amp designer stresses out "The transformer output can be anywhere from 14 VAC to 20 VAC and at least 200 mA. Don’t use more than 20 VAC or less than 14 VAC (except for the 12 VAC transformers listed in the parts list).Do not try to use a DC adapter. "
2.5 x 5.5 output plugs seems to be more easily available yet I guess it would need some plug adapter or find soldering iron.