I use the regular 9V DC negative center power adapter, and every so often the connector gets ripped or the internal soldering wears off and in middle of a gig the adapter stops working. It usually happens at the connector (barrel) side (see following fig):
What I had in mind is buy a heavy duty cable and solder it myself to the adapter so it's more durable, plus having an external power cord to the adapter so if I need extended length it's the power cord rather than the adapter cord.
What's the size of the connector in standard (i.e. Boss) 9V DC adapters? Here are some examples, looks like it's the 5.5*2.5, but maybe it's not even in this list.
Please disregard the other side of the connectors in the picture below. All I'm interested to know is the size of the connector (to the left).