Linear power supply custom built by Sean at CHC and was used to power my macbook pro music server, based on one of the CHC-CAP power supplies. I had Sean build this using Mundorf caps and a custom transformer from Canterbury Windings. Output voltage is 16.5vdc but can be adjusted up to 18v and down to 3v if required. This is a 230v unit. 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 have turned the voltage down to 12v and at present it is powering my blu ray drive which is obviously overkill. Will include the cable in the pic minus the magsafe plug. The unit is heavy but will post at buyers expense.