Boss PSA 230S Power Supply

Instantly eliminated all noise issues and gives enough power (500mA) to power more than one pedal from one Boss PSA with an appropriate split cable. I had to use it to believe that a good power supply will get rid of all unwanted noise in the signal chain, compared to a cheaper one.
I actually have 4 of them, gathered throughout the years, all still working flawlessly, and use all four plugged in a power strip under my Pedalboard Classic JR giving me a total of 2000mA and they power 8-9 pedals (mostly analog but also a couple of digital ones) without any problems.
No ground loops, no unwanted noise, no need for a professional power supply (such a cioks) yet!
Works really well and the build quality is top notch. I Have used them both live and in studio.
One minor complaint is that the cable is really really long which is useful when you're trying to reach a socket that's far away but for me that I use them with a power strip under my pedals it can get a bit cluttered under my pedalboard when I have the four of them together.
Worth the buy. Highly recommended!

It's a simple product, really: it provides 9V direct current (negative center) without any noise. That's all it needs to do, and it does it well.

Ordinary (read: not designed for audio applications) 9V DC converters can cause noise to creep into your signal chain. It's usually because they are either a) not isolated or b) switching instead of linear. This especially affects analog pedals with low mA consumption and light power filtering.

The Boss PSA 230S fixes that problem - it's designed for audio pedals after all. It's pricier than your garden variety 9V DC converter, but it's worth the investment. You're investing in a great tone, after all, and isn't that what all of us are chasing?