Well look what wandered in the front door.Why its another precision power supply. It appears similar in rating to the another beloved line, the Power Designs Precision, specificlly the 5020 (though the PD goes to 50V in the second range). Lets see how it compares in a few stats:PD: +/- 3% of full scaleHP: +/- 2% of full scalePD: 0.001%+100uVHP: 0.0005% + 100uVPD: 0.001% + 100uVHP: 0.0005% + 40uVPD: 100uVp-p (up to 10MHz)HP: 40uVrms/100uVp-p (up to 20MHz)(basically how does the output match the set value)PD: 0.1% + 0.5mVHP: 0.025% + 1mV (any where in the spec range after a 5 min warm-up)PD:< 50uSec to recover to within 20mV of set value (for a change of load of 80%)HP:<50uSec to recover to within 10mV of set value (for a change of load of 100%)PD: Doesn't address thisHP: 0.01% + 500uAActually, PD doesn't address the specs for their current feature at all, while the HP goes into a detailed break down of ALL of the aspects.Now we get to the ones people on here love:PD: 0.001% + 100uV over 8 hours, 1mV per week.HP: 0.0015% + 15uV over 8 hours (after 30 min warm-up), no per week ratingPD: 0.001% + 50uV per oC (0-45oC) and 0.002% or 100uV whichever is greater from 45oC to 60oCHP: 0.001% + 15uV per oC (0-55oC)So it looks like we have a heck of a slug fest between these two bad boys. Though one stark difference is despite similar drift and temp coeff, the HP does not use an ovenized voltage reference. Hard to believe both are over 40 years old, well PD released their first precision lines in 69-70 I think (the 5020 wasn't released until 79) while HP released this in 72.Now for the fun stuff.First, let me say the fit and finish on this thinking is very nice. Brushed aluminum, textured side panels, enameled front. The only plastic comes in the display, the voltage selector and a few knobs and switches. Everything feels very solid and the damn thing weighs a bloody ton. It's things like this that they get the monicker boat anchor.This is HP's version of digital, no knobs to turn. Just push the upper button to increment up one and the down button to increment down one.The 10-turn current setting pot.The beautiful insides. All of the traces that I can see are gold flashed and the gold is still shiny. Look at those 490uF 85V Sprague capacitors (Made in USA). The grey box is a small transformer (not sure what for). The large power transformer has 17 taps on it. A variety of canned resistors and other odds and ends. A bunch of film and disc caps. Oddly, for some reason, most of the large resistors are inserted into standoffs (as seen in the second image). What you can't see are the transistors mounted to the HUGE heatsink. They are hidden by that ribbon cable which is VERY stiff, so I couldn't move it to get a good pic of them. They are your typical TO-3 metal can power transistors. Also, note those large screws, they aren't for mounting the board to the case. So what could they be for?Yep, they are for mounting the screw terminal capacitors directly to the board. Which by the way are 40000uF 45V Sprague 'lytics, which the manual incorrectly lists as 4000uF. These things are about the same diameter as a can of RedBull if I had to compare it to something.The bottom, not much interesting going on here.The voltage regulator board in all its glory. Look at that gold shine. I also like the through-hole tantalums on board. Don't see those too often.A close up of part of the voltage regulator board. Everything on this board is top notch. Precision resistors from micro ohm(a variety of tolerances 1%, 0.1%, 0.05%), larger resistors from Dale, capacitors from Sangamo and Sprague, Zener diodes and transistors from Motorola, potentiometer from Allen-Bradly, Bourns and Vishay, op-amps from Analog Devices. The manual says the op-amps are from Sprague electric but they clearly have the AD logo on them (I'm really surprised my cellphone could pull off this pic). It's like a who's who of American electronic components companies. Sad to see the current state of affairs when you look at this.Behind the front panel, the large pot on the bottom right is the 10-turn one for setting the current limit. Let's take a closer look at that cluster of resistors under the voltage selector.Well I'll be, we have a trove of ultra precision resistors. 0.01%, 0.025% and some 0.1% to round out the mix. Basically, a voltage divider of some sort through these precision resistors to select the voltages.Lastly, we have the back side. First, you can see the huge freaking heat sink which is why it weighs so much and also why it is entirely passively cooled. The we have the simple warning message. No warning about how you will be killed, your dog will be maimed and how a swarm of locusts will descend on your house if you open the back panel. Just a common sense Hey look out, read the manual before messing with this thing. Now what's under this? Why your sense output and a whole bunch of other connectors which help in remote programming of voltages, paralleling supplies, hooking up supplies in series, setting various current features, etc. etc.Quite frankly, being as this device is roughly a decade older than I am, it out right amazes me. Not only for its features at the time. You look at today's supplies and especially the cheap ones don't come near to the qualities of this one. Hell you would think with the schematic being printed directly in the manual someone would have made a knock-off but nope. What also amazes me is that not only is this device made in the USA but ALMOST all of the components are as well. The only ones that I could see that aren't appear to be the Dale resistors which are made in Mexico.