My store bought Effects power supply has been annoying me lately, it's buzzing both from the box and in the guitar signal,it's bad tempered and cuts out and generally just puking up it's entrails, I've been fixing it over and over for years and I finally thought "bugger it I will make a new one" so I did.
It is a very simple build however it is not one to be taken lightly as it involves the mains so you need to take all due care and attention.
Use a metal enclosure and Earth the Chassis, this both adds safety and cuts any stray noise.
Make sure you use a fuse - in my case I used a connector that had a fuse compartment built into it
You will notice that I used a uncommon type of regulator, you can of course substitute this with a LM7809 Regulator, they are pin compatible though I suggest you try and find the ones noted on the stripboard layout.
Be Careful