I have coil machines with .22 wire on the coils. They pull 1.5 to 1.8 amps depending on the setup. This fatigues most power supplies and you get a situation kind of like when your coils get hot except within your power supply.
For example, the guys that make the Bandit said It wouldnt push them. My buddies National wont push them either.
My critical does fine without a hitch, but im not sure how long its going to last. Ive had to send supplies to them three times this year for repair. My old eikon Ems 200 does too, but it starts to falter after about an hour.
Im just looking for something more analog and made in the USA. Sunskin looks great but if it breaks I would have to send it to italy.