Oatley K272 DC power options.

Few questions if you don’t mind.

I would like build the Oatley K272A Headphone Amplifier Oatley Electronics but would prefer to use mains powered supply. Having looked at the kit and done a bit of research I notice that the new kit requires the use of 3v battery + 9v battery to power the device.

Now my questions are.

Would it be possible to run regulated 12vdc straight in at the 9v battery terminals?

Using the same regulated 12vdc would I be able to use a DC-DC Buck Converter LM2596 trimmed to 3vdc in place of the 3v battery?

The source of the regulated 12vdc would be from RJM Audio in the form of the xreg RJM Audio - The X-reg Voltage Stabilizer

I would like to say that i don’t have any facility’s for making PCB’s so would not like to go down that route. However if someone has a better idea of how I can get round my problem using a ready made or kit that is available I’m open to suggestions.

thanks