Random power supply

Hey, I'm old and dumb and tryna build a diy light from trash. Just trying to get my head into power supplies. I've found a couple of routers in the recycling bin and I'm just curious about their power supplies, wondering if I can make them work for me.
They have a Delta DPSN 525AP power supply which supplies -50v DC 7.8A. Just wondering if I could drive 4 Cree CXB3070's in parallel with that. That would have them at 1.95A each (or 3 at 2.6A, still under their max 2.8), right? Also wondering about that neg power, that would mean you just hook the cob up backwards, I mean swap the terminals over? Kind of exciting to think I could have a nice light set up for my 2x2 for the cost of a few cobs. Can you just add a potentiometer to one of the outputs to dim?
One thing that concerns me much is that 525W rating. Is that what it pulls from the wall regardless, or does that depend on the load you've got on it. So much to learn. I wish I had a few cobs and some fuses to play with right now.
Thanks for your help! I know I could just go buy a Meanwell and be done, but I'm having fun trying to figure this out on a shoestring. I know a little knowledge is dangerous. Put me out of my misery. Cheers

 

Ahhhhhh, I gotcha. So I can never go over that anyhow. If I can manage to dim them down to around say 1A each those cobs should be running about 35W. Ooo, I'm excited now. You've made my day. I just gotta remember I need to cool that somehow. Maybe with the 12v I can drive a fan for the power supply and a few far red LEDs
Lol ScOObyDOOby /Doobie Noobie: we're not related are we?!

 

Hmmm, well I was excited, but the more I read into reducing current output, the less excited I become. I think I'm going to have to find an on board potentiometer to make it happen. Not feeling hopeful

 

Hmmm, that could be my pot of gold. Gotta figure out how to test that now

 

Ok, so that just fine tuned the output voltage between about 48v to 52v. D'oh.

 

Yeah, I hear ya man. Trust me, I don't want to be trashing some good cobs. From what I understand about parallel wiring, you can just add a fuse to protect your cobs, so like if I added a 2.8 amp fuse to each cob, or lower whatever, you'll cook the fuse before the cob blows.
So I've slept on it now, and decided I'll just go for it. Yeah, I dont think I'm ever going to be able to dim that, but I saw a YouTube vid that said you can't have too much light. I figure if I just give it a chance, see what happens, nobody die. If it dont work out, I've still got my cobs, get a mean well then.
So here's my math: If I parallel 4 cobs over the 7.8A they get 1.95A each, which from what I can gather the cobs will pull use around 36v depending on their temperature. 36 x 1.95 is 70.2W? So I get fuzzy here, and if the cob is around 93% efficient that'll make them around 65W lights. I guess 4 of them in a 2x2 will either kill em' or kick ass?! I dunno. I've got nothing to lose, but time. No biggie.
Thanks for your comment HT. That's an awesome set up you're running!