5A power supply

Quad Cortex
1

I bought an alternative power supply for my QC and it’s 12V 5A instead of 3A as for technical specifications from Neural
Assumed that 2A too are enough to power the QC I would like to know if 5A is ok or too much and if is it dangerous for the unit

2

The QC won’t use more power than it needs. You’ll be fine

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3

Electrical engineer here. 5A rating on the power supply just means that it’s capable of providing up to that amount of current at 12V. The QC will only pull as much current as it needs.

I would much rather have a power supply that can supply 5A instead of 2A in this case.

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4

Assumed that 2A too are enough to power the QC

I can’t remember who it was, but one of the power supply manufacturers lab tested a QC and found it drew no more than 1.8A ish.

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5

I wonder with certain devices how comprehensive the testing is - different blocks used, different actions executed, different global configurations, connections, etc… Just testing the peak draw by just powering up and simple usage may not be adequate. Sometimes changes executed on the device that require more amperage are not obvious tests.

I like to err on the side of providing, at minimum, the amperage that the device manufacturer recommends.

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6

I got the impression they were fucking with it to attain peak draw, but again, I can’t remember where I read about it. It’d be pretty stupid to go to the lengths of rigging it up to proper measuring equipment only to just power it on once and call it a day…

NDSP themselves said 2A was adequate. Obviously it’s inefficient to run a powersupply near 100%, hence supplying it with a 3A one.

7

I found this from 2 years ago.
https://www.reddit.com/r/QuadCortex/comments/1335gsb/testing_current_draw_of_the_quad_cortex_and/

You can see that it hits the peak of 1.7A at about 1:25 while still booting up, when the display brightness is at maximum.
After that he is testing two presets with 79% and 36% CPU and the current is between 1.1A and 1.15A.

Not an exhaustive test but you can make some guesses. It seems like display brightness seems to have more impact than CPU usage.
And in this basic scenario (Guitar, medium screen brightness, XLR outs) you probably wont get close to 2A.
With phantom power mics and screen on full brightness it may be able to push it there, but I have no intention to test that :smiley:

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8

Generally, I’d agree with you, but you never know how rigorous the testing was, or what might have changed in the firmware or even different generations of hardware since then that could potentially create higher peak/momentary draw.

It appears that a fair number of users have had issues, potentially because of non-factory power supplies. Some of this can no doubt be written off to improper settings or cabling, bad, or incorrectly rated third-party power supplies. It is at least worth noting though. Any decent identically rated or even higher amperage alternate power supply, hooked up properly, should work. All things being equal, if you are still getting crashes with a decent third-party power supply, I would assume the problem is elsewhere, e.g. firmware, hardware. Perplexed if this is not the case.