Archive of the former Yahoo!Groups mailing list: Korg Poly800/EX800 Users

Somehow, nobody seems to have pointed outthe major differences between a modern-day regulated switching supply and anold fashioned large transformer type adapter.

The old transformer type adapters arenon-regulated, and the voltage varies with the current that is being used. Ifit is rated for 9VDC at 300ma, it probably measures 12-13 volts when nothing isplugged into it. The voltage will drop as you draw more current, and if yourequipment really needs more than 300ma then the voltage will drop below 9 volts.A large transformer type adapter that is rated for 1000ma might measure as highas 20V with no load on it, and only drop to 15 volts with only a 300ma load onit. That might put a bit too much stress on the 9v to 5v regulator circuitinside the Poly-800.

 

On the other hand, if you are using anewer switching-type adapter, it is probably much smaller since it does not needa big transformer in it, and it will put out a regulated 9V at any currentlevel from 0-1000ma, so there is no problem using one rated for 1000ma. A/Cadapters rarely have markings on them to show whether they are switchingsupplies or not. You can usually tell from the size. If not, just check thevoltage output with nothing plugged into it. If it is 11 volts or higher, it isan old transformer type. If it is above 15 volts, then you may be shorteningthe life of some of the power transistors in the 5V regulator in the Poly-800.

 

Don Backshall