PSU-3 dying, audio noise?


#1

Hi there, just noticed a horrible frying noise on the audio from my A4 mk1. I noticed the PSU-3 was very hot. Removed it and put on my Digitakt PSU-3b and all is good.

But will the 3b cause a problem? Under powered 2A vs 2.5A. Can I use any PSU with right tip and rated 12V 2.5A? Need something quick for overseas trip vs waiting 2-3 weeks for Australia delivery!

Cheeers


RYTM MI & MII Power Supllies
#2

It’s a big ask to have someone respond to this in a black/white way and I’m fairly sure support would only encourage you to do it with the official device

However, it seems fair to presume that a decent quality alternative with the correct amperage and polarity/tip-size would be just fine

I’d also suggest that if you’re only using some of the A4 functionality (e.g. perhaps not using the CV side and ensuring all CV channels are grounded) that you may be safe to work with the 2A psu - especially if you keep an eye on its temp. It’s safe to assume Elektron will have a margin on top of the worst case scenario, so I’d think you can make your own risk assessment based on some of this

The fact that it is more likely to damage the PSU is not the issue here per se, I guess you need to be careful not to start a fire - so I’d just suggest running it past support (wrt the 3b) or picking up a spare 3rd party psu as a stop gap


#3

I wouldn’t do that. You are feeding 30 watts instead of 24 into the digitakt; although I have no idea whether that is significant or not. However; minimise risk to your goodies!


#4

Cheers. Yes ended up not risking it for a travel rig I need for two days time, left the A4 at home and ordered an equivalent supply vs the overpriced official one. Like you said I wanted to use CVs and then things would probably get risky, a blown PSU and no alternatives away from civiization .


#5

Its the other way round, using a lower powered digitakt psu on an a4


#6

No, as long as you have the same psu voltage you are on the safe side.
Imagine the voltage is like the size of the pipe feeding the current. If you have a psu with a higher voltage than needed, when your device requests a current the actual current that flows is higher than needed as the pipe section is too large (ie voltage). There you can fry your device!


#7

Duly noted; thank you for the explanation.


#8

Aren’t there limits? If you plug a 12V 72A battery for example? :grimacing:


#9

Nooo . :zap:
I would instead worry on the quality of the psu, i.e. it’s ability to maintain a constant voltage.


#10

Please contact the support and report here with the answer.
Or maybe @Olle @Ess you could answer directly here if it’s safe or not to use a PSU-3b instead of a PSU-3 on an A4 mk1 ?


#11

Yes, it’s fine to use a PSU-3b for testing


#12

Thank you @Ess for the answer.
And for regular use ? Is it not recommended or perfectly OK ?


#13

Folk don’t seem to know the most basic of Voltage and Current Vs Power.

ANY circuit needs a certain amount of Voltage to function, this is specified, i.e. 12V.

The Voltage appears across the device, Happy Days.

When the circuit if functioning correctly it will draw a certain amount of Current.

The amount of Current multiplied by the Voltage is the power drawn in WATTS.

So as long as the Voltage is correct and the available Current enough the circuit will draw the correct power.

If the Voltage goes up a little, the current will sometimes drop, the circuit taking the same amount of power.
However this is not always true and the current may increase too and hence the circuit will dissipate more heat.

The Voltage does not have to be exact as any 12V circuit will work from 10-14V perfectly well as they’re Analog circuits, however 5V cant be any lower than 4V5 and no more than 5V5.

Remember Voltage is offered across the circuit and the Current is drawn.

So you can use a 12V 1000A (12000W) PSU if you want!

Str.


#14

In theory “yes”, but using a PSU with a much higher max. current is quite similar to replacing a current fuse with a nail. Of course it works, but in case of a failure you get into real troubles. The max. current limitations are there for a reason (and it’s not only due to manufacturing costs).

Have you seen what happens when 1000A gets short-circuit in comparison to, for example, 2.5A? A damaged device will be your least problem then.

And “no” it don’t need to be a 1000A PSU to get a device burning in case of a failure. Much lower possible loads (the max. current rating) are enough.

So, please, don’t give such dangerous advice on a forum (the sentence I’ve quoted)!


#15

Always fit the appropriate size fuse!

Str.