I think I need to get a larger power supply for my MkII as nothing I have on hand seems to deliver the optimal amount of juice (the lights are always in the dim mode). The adaptor that came with the unit has the EU prongs but I’m in Australia so have to use a janky plug adaptor on it (when I plug it in through the adapter though with the supplied power pack, the lights are all nice and bright). I’m looking at options and see that there are some quite potent ones using the new USB-C QC4.0+ / PD3.1 standard (delivering something like 140w at 5V). I take it that the Mono isn’t going to optimise the new power standard but is there any benefit to erring on the side of ‘plenty’ here? Anybody else using aftermarket power supplies? Recommendations? I’m a bit bewildered about the power delivery as even the USB-C charger for my MacBook doesn’t seem to deliver enough wattage even though it’s rated at something like 3A.
I own a Mono v1 and asked Mathieu about the EXACT power requirements once. He replied “15V 0.77A”, so I connected my Mono to a Cioks DC7 pedal power brick that provides 15V 0.8A power via DC (center positive) and I’m a happy camper as that Cioks sorted out seperating it’s power ports physically. You should mail Mathieu and ask how much DC power the v2 needs if you consider this solution, but taking into account that “5V x 2A = 10W” is apperently sufficient and “15V x 0.77A = 11.55W” for my v1 is quite a bit more, the v2 should be in the same range (670-770mA).
Regarding “alternative USB-power sources”: I had extreme difficulties with USB hubs. Most of them are very, very noisy. The best so far was the StarTech 10 Port Industrial USB3.0 Hub (ST1030USBM) which costs a fortune but provides 10x 2.4A with a total of 50W and USB 3.0 speeds (most galvanically seperated USB power hubs are limited to USB 2 and most provide only 0.5A per port, I searched forever for the Startech one).
I still can’t use it with synths – I think I tried my Norand Mono, the 1010Bluebox, 1010Blackbox, a Toraiz AS-1 and a Tasty Chips GR-1 and there’s still interference, especially when you connect a laptop or an SSD to the same hub, even though it’s meant for industrial use under critical conditions. I tried other hubs like the Bravour 16-Port 1U rack M2.BRV16CH, talked to the engineers before I bought it … and threw it away after 2 months as ground loops and stuff drove me nuts.
At Superbooth '23, I met a guy who used an “Atolla USB Hub with Power Supply / USB 3.0 Hub Active” at his booth and swore it didn’t make any noise, but I haven’t confirmed this.
What works is a USB power adapter cleared for clinical applications – in Europe, I have the Meanwell GSM12E05-USB “12W AC-DC Reliable Green Medical Adaptor” that provides 2A, costs under 15€ and makes no noise whatsoever as it’s specified to work along cardial pacemakers patients. Maybe Meanwell als has an Oz version of that. Or else just search for “medical USB power” and you should be good.
I’ve battled ground loops for 9 months until I invested heavily in clean power supplies like the Furman PL8 and ground lifts like the Palmer PLI02. When I even ask some nerds on Europe’s biggest synth fare what USB brick they use, it must be a severe problem 
So, yes, the whole USB power thing with audio gear is a bit fraught. USB-C is really useful as this all in one conduit; however, it’s apparently still subject to the same noise issues that USB introduced 20 years ago. I’ve also been trying to pair up my OP-1 with an Iridium and have had no end of ground loop issues there (that’s after replacing the original power supply to the Iridium with one of these Hi-Fi no noise power supplies. I was a bit incredulous about that but it’s done the trick for the noise I was hearing on the synth itself. The ground loop was resolved with a cheap ground loop isolator in the audio line).
I’m going to look into either a medical grade USB power supply or just one of the high wattage ones for laptops. Again, I’m not sure why my Apple one isn’t working correctly but perhaps there is some power management bit in it where it’s limiting output to non-apple devices. I have Furman filters in the studio; but, at least thankfully with the Mono, my problem isn’t noise. It’s just not getting enough power. I also wonder if that may have something to do with the weird operational problems I’m having as well.
Time for some enterprising electronics manufacturer to step in and make an isolated audio grade power supply for synths. I’ll email Mathieu for advice and update here.
Also make sure that you use a balanced “stereo” cable for the Norand, even if the Mono is just mono. If you use an unbalanced cable, noise issues are likelier and also the signal will get quieter. I had the reverse problem with other synths … used 2x balanced cables for 2x unbalanced ports and either had weird noise issues or a significant volume drop, so make sure you always use the cable specific to the port of that synth. You can always use something later like the Radial StageBug 6 to convert the signal from unbalanced to balanced ot vice versa without loss and to bring it en par with your mixer / amplifier. But other than that, never mix balanced and unbalanced cables 
See below for word from HQ. I think what may have happened is that I was using USB-A to C cables with my power supplies and they apparently don’t communicate between devices what is needed and it must have been defaulting to a lower wattage. I’ll have a look about for the power supply Mathieu mentioned…
You don’t need such a high power supply ! A very simple USB-C 5V 3A supply will do. Mono drains about 11W of power.
The issue is, some super high-end power supplies only use USB PD negotiations, and if there is no USB PD device connected to it, it won’t advertise the 5V 3A capability via the old school way, which Mono uses.
Mono MK2 is NOT USB PD, it uses a previous standard that uses the CC pins to sense how much power it can draw.
So long story short, what you need is a USB-C 15W or 25W plug (not USB A, since the CC pins are not connected on these).
We provide the EU version of this one with Mono (so this should work in exactly the same way with the AU one) !
Well, I was having weird sound issues with the Mono v2 using the included PSU. I swapped out for my laptop PSU and it sounds a LOT better. It was working fine, so maybe my PSU died? Shame as I have only had it for a short period, maybe 3 weeks.