I tend to agree, I have a bunch of supplies, but my 12 V one is a Fixed voltage power supply, SELECTABLE from 0-32 V, 10A. It's from Harrison Labs, which was bought by HP. I paid $15 some 35 years ago. Replaced 3 transistors because it was repaired improperly and only got the manual about a year ago. You have to change the transformer taps depending on voltage. I also have a +-(12-15 V) and +5 that was part of something. It does not like reverse voltage. It takes out the 723 regulator. Then i have a couple of 0-30 3A supplies. For fun, I "boxed" a ebay step-down regulator with both 5.5/2.1 and 5.5/2.5 inputs and has an adapt-a-plug output. It has LED meters and current limited. So, I can replace nearly any wall wart I have to with a working 12 V, 1A wall wart and this regulator.