Advice on Powering Remote Control in Aleph J/BA-3

Hi,
I'm in the process of building an integrated amp with an Aleph J and BA-3 front end. I am planning to power both off of the 24V Universal Power supply, using a 18v/18v 500VA transformer.

I want to add the following remote control ladder attenuator, which appears to require 5V/1A.
High Quality Audio & Industrial Attenuators


What would be the easiest way to power it? Am I going to need to try to fit another transformer in the case?

Much Appreciated!