Sean Jacobs built this psu for my Macbook pro music server based on one of his CAP psu and has a max output current of 5A. For this unit though, he used Mundorf caps and a transformer from Canterbury Windings and is a superb performer. Although the voltage output was set to 16.5vdc to suit the macbook, it can be adjusted to 18v and down to 3v. Here is what Sean told me: Hi John, the voltage can be altered on the small preset potentiometer (small blue box with a brass screw sticking out of it – turn the screw to adjust voltage). You’d need to take the lid off to do this, and the PSU would need to be powered up to change and measure the output voltage, so if you do it yourself then do be careful! Maximum output current is indeed 5A. The voltage could go up to 18V at a push I think, it can go down as low as 3V but this would give a reduction in the maximum output current. I’d say 15V at 5A is still fine, 12V would be OK at 4A, 9V and below more like 3A max. The fuse in the rear panel should be changed for a 4A or a 3.15A fuse if the output voltage is to be reduced. I can supply new output cables to suit different equipment as well, if the new owner needs it. I will include the cable that Sean made up for me minus the magsafe connector. The psu is now surplus to requirements after selling my Macbook and moving on to a dedicated server. The unit is heavy and buyer pays for postage.