DIY Power Supply Thread - Questions and Help

Power Supply Thread!

For all of your Questions and Answers.

Feel free to share all of your Power Supply Related Topics here!

I will start with a Help Request.

I am building a 9v Power Supply for reasons undefined that will be shared in this forum later, but I need to add a 7.5v rail.

I figure I can do this with a L78S75CV and I am wondering what else needs to attach to the rail, any caps or diodes, etc.

I ask for assistance so I do not make any grave mistakes, since this is dealing with a wall plug… lol.

Thanks all!

1 Like

Would this make more sense?

I don’t think you need the extra diode, but adding the post filtering cap is probably a good idea. I’ve been getting into power supply building a lot lately. I’ll share my modular one that I based on this MFOS design when I get a chance.

1 Like

you’re the best :smiley:
Have helped me a coupla’ times now :slight_smile:

I’m about to order parts for a power supply for kosmo modules. Anybody recommend a decent pcb in US? For smallish setup 8-10 modules. Also need good bill of materials cause I’m a noob lol

I highly suggest the Frequency Central MicroBus or basic power supply kit.
Only took a week and a half to receive from the UK to Wisconsin.


Right on. are the states just slacking on the synth gear or what

1 Like

Actually, just checked and SynthCube has the FC Microbus PCB’s In Stock for 16!

They’re in the US! :slight_smile:


Thanks dude I’ll check it out

1 Like

Sam actually has a Video where he utilizes their Power Supply in the DIY Modular Case Video

Here is the BOM for the MicroBus. :slight_smile:

Keeps you from having to use a flying bus or separate bus in general when you first start building!


+1 for the microbus. Easy as piss to put together. They already have a BOM on their site, but i can make a Tadya list for anyone interested.

I had to buy the walwart from somewhere else. I think i got it from Jameco.


I have ordered two frequency central power supply pcb’s and other diy pcb’s [ befaco, MFOS ] from synthcube. they are great to deal with, easy site to navigate lots of different diy / fully assembled modules . fast shipping .


i am a fan of synthrotec the power distro board . dead easy to build fast shipping in the us . a meanwell dual power supply is what i run in my euro rack maybe 100 bucks all total

1 Like

I’m interested! Could you create or send me a Tayda parts list please?

1 Like

I’ll make a thread soon.

1 Like

If you order a meanwell RT-65B you just need to connect the outputs to any power rail you want to build.

The easiest way is to use stripboard and IDC 10 pin sockets.

Total cost would be something like 30$ and it would work fine. It does for me :slight_smile:

There is no BOM since this specific meanwell powersupply provides the 3 needed voltages directly (+12, -12, and +5 v)


You need - 12/ +12v to use with euro rack or any serious modular
Plus needs to run on 12 vac

1 Like

My Build above isn’t for Modular - it is for a Circuit Bent Casio Keyboard and some FX Circuits. :slight_smile:

I have a Microbus from Frequency Central for my Modular stuffs :slight_smile:

1 Like

Finished my power supply for the Casio mod over in the Circuit Benders Corner Thread.

It puts out its respective 9v and 7.5v targets :smiley:

I added the 9v Bus for the 2 Required 9v applications and the other 2 for any other future expansions.


First post here, apologies if I am posting incorrectly or in the wrong spot. Anyway, I have a question about powering homemade musical circuits. It seems that almost every musical circuit has or needs to have an op amp in it, requiring a dual rail power supply. Every time I try to find out how this is done, I find one of two answers: 1. Virtual Ground and 2. Benchtop power supply. For the virtual ground, I have made several and they all produce +/- voltage, but are not stable at all and in the end this does not seem usable. Similar for a benchtop supply, while this works, it doesn’t work for a standalone creation. I realize that people buy power supplies, as like the ones linked in this board but I am wondering how to achieve this without one? How do I make a standalone box that has both oscillators and an op amp (or several) within? Maybe there are other chips as well, chips that might need 7v while the op amp needs +/-12v. I want to be able to do this without needing a special power box.
Thanks for anyone’s input,

1 Like