Octatrack on Eurorack power supply

Hey - I have a future plan on getting my OT in a travel case with modular, with a singular power supply for everything. I will of course consult an experienced technician to do everything once the plan is done, but in this pre-planning phase, I need someone to educate me on this;

As per the OT manual, the power consumption is 7w.
According to Thomann, the PSU-3c power supply outputs 2000 mA.

The konstantlab BoardPWR set that I have says that it’s output power is 2000 mA. But the power supply in that set outputs 45w.

How does this work, and what does it mean exactly? Is it that the two bus boards can output 2000 mA each or in total? If 1w is 1000 mA, where does all the excess watt go? Does this mean that OT needs 7000 mA if it were a eurorack module?

• I have read from other users on this forum that the power switch is a “hard” switch, and therefore there should not be a problem with connecting to another “hard switch” - the eurorack bus board (right?)

• For ergonomically reasons, I will remove OT from the casing, and place the lower half with the audiojacks and stuff at the bottom of the case. The two ribbon cables that connects the lower half of OT to the upper half, what are they exactly? I will potentially need longer ones.

If current draw is calculated by W divided by Voltage, is it correct to say:

7000 / 12 (7w divided by 12VDC) = 583,333 mA

Meaning that if the OT was a module, it would draw 583 mA. Yea?

Ambitious plan. It sounds like you’ve already thought it out but do check all the power loads. I burnt out a modular power supply because I had assumed it would simply not work if I had too much power draw. In my case it was a slower process I think of overloading it for weeks. Luckily the consequences were limited to having to buy a new power supply but I’m sure it could have been worse.

Thanks, I really haven’t though! I did have some eurika moments after posting, and also finally found some good discussions on here regarding power banks, where I can quote a fellow user that the OTmkII can run off 700 mA.

Luckily, since it is a travel case, I will have no more than a skiff, and so far modulargrid gives me an usage of 779 mA.
I still would love to hear from others how the math makes sense for the power supply, me meager brain doesnt quite get it yet.

How much power is the proposed power supply capable of? You’ll want to make sure you don’t use up more than 80% of that limit. I would also try to make sure that you maintain a separate power switch for the Octatrack so you can start up the modular system first, and then turn the OT on a few seconds later. That should help prevent any troubles on the power supply if you try to turn everything on all at once. It should work, but be cautious, and be aware that you might run into unforeseen problems. The easiest way to ensure success is to make sure your power supply is plenty big.

Yeah, you are right, maybe the tech should install a sequencial switch so it doesn’t turn on at once, but it still connected to one switch.

The power supply is 45W. The power output is 2000 mA, and my system (should) take up 1479 mA. So should be Ok.