Is a multi effect PS a DIY?

[Jay Bones]

Or should I buy one?

Specifically one that has multi volt outputs, and even a couple with adjustable (sag) voltages.  If I understand correctly I'd need a way to bleed off some of the current, converting it to heat, and a heat sink to disperse it.

[bluebunny]

Buy one.

[Josh?]

Or don't buy one. I personally am not knowledgeable enough to help you in any way with such a project, but I do know that if something has been done before, then it can be done.

If you want one immediately, buying one sounds like a good idea, but if you're really interested in how they work, and willing to spend a ton of time learning more, then by all means build your own. It sounds like a really hard thing to do, and could easily become an expensive long term project requiring lots of research and money, but if you put in lots of work, the worst that could happen is that you learn things.

Personally, I think it boils down to your motivation: why do you want to build one?

[Sooner Boomer]

Or should I buy one?

Specifically one that has multi volt outputs, and even a couple with adjustable (sag) voltages.  If I understand correctly I'd need a way to bleed off some of the current, converting it to heat, and a heat sink to disperse it.

A linear power supply is quite easy to make.  Even one having multiple positive and negative voltages.  First, you need a transformer that can convert mains voltage down to something just above your highest working voltage (or cheat*) and can provide all the current you will need.  Next, you rectify the AC into DC and add a bunch of filter caps.  You follow this with either the fixed voltage (or adjustable) three pin regulator of the voltage you need.  The LM78XX series of regulators give you easy access to fixed voltages - https://en.wikipedia.org/wiki/78xx    The LM79XX series give you negative regulated voltages.  The LM317 is an adjustable regulator from about 3 volts to 30 volts. 

* you cheat by buying a DC power supply for something like a computer that already has a regulated/filtered output at a voltage higher than you need, then stick a three pin regulator on *that* to drop the voltage down where you want it.

Switching mode power supplies take a bit more understanding of electronics, and a bit of engineering to get right.  However, there are plenty of designs out there.  Copy one, file the serial number off, and call it yours...

[JustinFun]

I was part way through typing when Sonic Boomer replied with pretty much what i was going to say!

I've done this in the past with mains transformers and voltage regulators - but I'd strongly recommend staying away from mains voltage and using a 24v adapter which you can then regulate to whichever voltages you want.

There's a voltage sag schematic at the bottom of this page http://www.muzique.com/lab/patent2.htm - I've not tried it so can't vouch for it.

Don't forget a 7660 (or similar) charge pump circuit for -9v as well!

[Sooner Boomer]

"Sonic Boomer"... I like that!

[stallik]

Yeah but.
I've been making my own for years. 99% of the time, everything works great but then I build a really fussy pedal that introduces noise in that pedal and others in the chain. I chase the problem for ages then try a good commercial ps. Problem goes away.
Just saying that there are real experts out there that will always know more than I when it comes to power supplies.

[Sooner Boomer]

Just saying that there are real experts out there that will always know more than I when it comes to power supplies.

Isn't most of life like that?  There's always someone who knows more, you just have to be receptive to learning.

[amptramp]

You have to decide whether you need UL, CSA, VDE or any other such approvals for something that plugs into the power line.  If you are building it for yourself, this may not be a problem.  If you are building it to sell, these things are necessary.

[GGBB]

It's probably a good fun exercise to design and build one, but on a practical level I don't think it's worth it. I spent a bunch of time researching and designing one a few years ago and had everything completed down to the PCB layout and bill of materials. When I costed out the parts, it was going to be almost as much as a commercial PS that had all the same capabilities, and would have been physically larger by a fair bit, so I didn't bother.

Another factor is fitting it on your pedal board. Many of the commercial units make brackets available to mount easily and nicely to PT style boards.

[roseblood11]

You have to decide whether you need UL, CSA, VDE or any other such approvals for something that plugs into the power line.  If you are building it for yourself, this may not be a problem.  If you are building it to sell, these things are necessary.

These things are necessary whenever you use it. If your homemade power supply causes a fire, you'll be in a deep shit. A burned down house, dead or injured people... And the insurance won't pay one penny.

[Ben N]

Some diy resources, should you go that route:
https://www.diystompboxes.com/smfforum/index.php?topic=83972.0
http://www.geofex.com/Article_Folders/Spyder/spyder.htm
http://geofex.com/article_folders/oldspyder/oldspyder.htm
https://www.tedweber.com/wpdlxfmr-1
https://www.tedweber.com/wpdlxfmr-2
http://www.muzique.com/power.htm