Cheap power supply, what can go wrong?

Hi, still waiting for my 301 but in the meantime i thinking about making a small portable case for sampling/outdors-sound-computing. I looked at this power supply: Frogleg Synthesis – Beetle Power Supply PCB – Thonk – DIY Synthesizer Kits & Components

would it be suitable for the 301 and a ladik preamp?
i dont se much info on over voltage protections etc


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Hey Mah,

Everything you need to know should be here:

If there is any information missing please do let us know and we will do our best to answer.

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ah thanks, so the 301 has built in protection which should make it safe to use the power supply i linked?

Not sure what the voltage protection has to do with the power supply you use?

You must use a compliant power supply unit, which the beetle looks like it is and connect the correct voltages together, i.e. get the cable the right way round -12V to -12V 12V to 12V.

Don’t rely on the red stripe, check the values with a cheap multimeter before plugging in.

You should never put the voltage protection to the test, it should never be required to use any power supply, it’s just there in case you make a mistake.

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I should add, if you don’t know about power supplies I would not recommend building your own like this, you really should know what you are doing before embarking on a project like that!

Why not get a 4MS Row Power, they are very reasonably priced and I have no problems with mine.

Ye ofcourse, i just want to on the safe side, my real question would be: would it be any advantage getting a more expensive power supply with built in voltage protection, like the 4ms one?

and ye, that kit looks real simple, i built a few kits earlier that seems far more complex, at least in my eyes

4MS Row Power and ER-301 are good buddies!

I don’t understand why anyone would compromise on power, I can’t choose for you or make any recommendations really :slight_smile:

Sure, re. the build, but I would still advise caution and that this is one area where you should really understand what is happening, not just blindly follow instructions.

If you have questions about particular power supplies you should really ask the manufacturer of the power supply for any additional information you require.

There are also a lot of very good threads on MuffWiggler about power, I would highly recommend reading those. They helped me make the choice that suited me.

edit: hope this doesn’t come across as dismissive or anything, it’s just a huge part of Eurorack, things go wrong with power more often than anything else i.e. people blow things up because they made little mistakes.

I really think everyone who is interested in Eurorack should really do their research until they feel confident about everything related to power.

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My highly non-technical advice: If you have the slightest inkling of doubt about connecting your ~$1000 ER-301 to a ~$10 DIY power supply, don’t. :slight_smile:


haha yes! the same argument that made me post this thread! i just wanted to stay positive with DIY spirit n’ all!

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No at all, thanks for all the tips! i was just getting a little over my head with ideas of building a small case for next to nothing :slight_smile:

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Congratulations on your ER-301 - not long now - and welcome :slight_smile:

Totally. Well, hey at least plug some lower cost modules with shorter lead order times into it first and make sure no smoke comes out, eh? :slight_smile: The ER-301 has totally transformed my modular (for the better). I can’t imagine how bummed I’d be if I fried it.

anyone powering 301 from a tiptop uZeus?

I am. No issues with it in a moog case with a teletype, walk and disting. No noise or any problem that I am aware of.

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thanks! i power a 12ux104hp with 2 uzeus, never had a single problem :slight_smile:
do you leave the switch on the er-301 to REG or tell it to pick up the 5v?

Definitely leave it on REG. Quieter and safer.

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thanks Brian! the creature was cleared from customs and now it’s supposed to land tomorrow or monday. can’t wait :slight_smile: