So my GPD-3303S arrived today. A few quick tests - it's the kind with the offset spacing for the fixed third output and as expected I couldn't get it to overshoot. However, the voltages are all about .1V low - set on 5V it measures 4.9 on 3 different meters, 3.3V measures 3.2, etc.
The other funny thing are the two adjustable outputs. With the output off, I can set both to say 10.000 volts. Turn on the outputs, output 1 drops to 9.985 or something, and output 2 rises to 10.053 or something. Confirmed with actual meter readings as well, Ch 1 is always a little low of the set point, Ch 2 is always a little high.
I also discovered my GDM-8251A is way off in the slow acquisition mode. It disagrees with the power supply meters by as much as 100mV. At first I put it down to the supply's meters being off, but I switched over to my Fluke 45 and they agree within a few mV. Switch the 8251 to medium mode and - now it agrees with the 45 and the power supply meters, within a few mV. The difference gets bigger at the higher voltage settings of the power supply, at around 5V and less it's dead on to 3 decimal places.
So I guess I have some poking around to do, see if there is an adjustment to the 3rd output. Not sure if I should be concerned about the way Ch1 and Ch2 behave when switching the outputs on. That just seems weird to me. Does it in Series mode, too. In parallel it pulls both sides down to the lower of the two, which is always Ch1.
In the meantime...hmm, what can I buy next, since obviously I didn't win a Tek scope unless I happen to get picked tomorrow. Maybe that solder/desolder station I want, though that's not exactly test equipment.