For more info please see this blog post.

https://audiodiwhy.blogspot.com/2021/11/long-live-fracrak.html

If you're going to build your own audio stuff, you have to put it in a case, right? Ah, that's where the choices start. My DiWhy friends work with Euro mostly, some MOTM, and a few the social media savvy "kosmo" format.

My geek audio buddies still aren't sure why I build almost exclusively in Paia Frac, but I'm sticking to it.  

It's a pretty uncommon format, but this week as I was blowing up power supplies I was glad I use to it rather than some of the other more popular choices.

+/- 15V Frac power with temp front panel....

I was doing some recording when all of a sudden from my noise generator came a nasty 60 cycle hum. Not all my modules did this, just a few, and I quickly traced it to one of my original (circa 2003) Frac power supplies.   that were powering the noise modules as well as some balanced modulators.

I have already posted building a custom 15-15V linear supply (post is here).  

I hate 60 cycle hum, so let's build another.  

Frac power is modular, like everything else about it, and modular engineering is good engineeering.

A new linear supply is easy and uses mostly junk box parts:

I plugged in the new supply to test--SMOKE!  

This blew up a surplus16VAC 40VA wall wart as well as both of the regulators.  

Hello?  

The diodes used to safeguard the regs from reverse voltage looked like chunky diodes in my junk box, but turns out they were precision low value hight watt resistors. Ooops.  

Not a big deal to replace impacted parts and put in diodes where they are needed; now it works.

The good news here is that when you have a power supply problem with Frac, it doesn't take out your whole rig, and conversely, if you have a bad module (DiWhy--that will never happen right?) it won't take out your only power supply. Frac is also a reasonable size, not too tiny, but not like MOTM or Moog or synthesizer.com formats where it takes up your entire living room; Frac is really affordable, fits in a 3u 19" rack case, and maybe best of all, PAIA is a cool small mom and pop type company.

Overall I am sticking with it.

Note that PAIA supplies (this clone is based on some of their earlier designs, but beefier in terms of sourcing and sinking more current) use a ton of .1uF caps really close the the .1mil headers. I have discussed this with some real EE's and they say that .1uF cap inclusion makes no different close to the headers and can be omitted--these caps need to go on the boards that are being powered, not here. 

I may upgrade the design in the future, but for now, you can leave 'em off. So far I have left them off my recent builds and can't hear any difference with ripple, buzz, or other unwanted distortions.

You can download the gerber and BOM for the power supply I use here from my generous sponsor PCBway's project page, here. Please help support this geeky blog by checking PCBWAY out and please consider using them for any fab work you dream up.  

If you come up with any sort of mod or change comment below, I am curious what you folks, my trusted readers, might come up with.

See ya next time.