PSU for Allo Volt Amp

I know this topic came up before, but I still couldn’t find an answer.
I’m trying to get a suitable 19V PSU to fit the barrel connector on the Allo Volt Amp (NOT the Volt+). Allo claims the barrel connector is a 6.5(OD)x3.0(ID), but although I thrawled through many online stores selling laptop and bench PSUs, I’ve never come across a 19V supply with a barrel connector having those dimensions. Not even the universal type of PSU with dozens of connectors has one like that (for example amazon.de/dp/B01KBYJEBK/ref … B007HXN064).
Any help would be greatly appreciated as I currently have two of these amps lying idle…

In case anyone is in the same situation looking for a 19V PSU to power the Allo Volt, I have located one which does the job beautifully: amazon.de/gp/product/B01N3NV7UY. Hope that helps.

the mating plug has 5.5 mm in diameter, widely used in a variety of consumer electronics with different wattages and voltages.