On equipment grounding in a Crown IC 150A preamp.

[SoulFetish]

I have a Crown IC 150A preamp that was given to me. This is a good opportunity, as I'm hoping to gain experience and become a competent technician beyond guitar/bass amplifiers. See Schematic here:

I'm looking to service it and sell it, but I'm hoping you guys can help me with something. On the back panel, adjacent to the mains chord, there is a series of auxiliary outlets to supply mains power to other equipment. See below:

These are all polarized outlets and I noticed that the power chord was a non-polarized 2-prong ac chord. Upon inspecting it further, it looks like someone replaced it with 2 wire heater chord. Not only that, but I don't think this device meets the class 2 requirement for a non earthed device.
I would like redo the mains wiring to meet modern safety requirements, however, I want to know if any of you have experience in hifi who can advise me on the what the protocol is. Mainly in that some of it is a painted chassis, consisting of many panels, which are fastened together.
I've taken some more pics of the device:

[Enzo]

I have one of those in my living room, bought it new about 40 years ago. Amazing how little is in it. I have a matching DC150A power amp with it.

Your schematic tells the tale, the thing was designed with two wire power. The power amp came with a three wire cord, but the IC150 even came with one of those adaptors so you can plug the power amp into it, without snipping off the ground pin. This is normal and helps prevent ground loops.

I think these are nice amps, though not flashy. Every Crown amp I ever bought came with an individual unit analysis sheet, showing test results for distortion, noise, etc as well as a graph of frequency response. Some tech had to sign off on the testing. The design is old, state of the art back then, but I am sure there are "better" ICs than the LM301. But before thinking about "updating" those ICs, put the unit through its paces.

I had to clean the rotary switches and pots over the decades.

Most of my stereo gear has two wire power cords: tuner, turntable, cassette deck, EQ, etc.

Frankly I would leave it wired as is.

[SoulFetish]

Thanks Enzo. There is literature in the service manual about how to wire it for different line voltages which show an earthed mains, but I’ll just change it to the appropriate polarized 2 prong.