Here's a cheap way to make a tilted stand for your guitar amps.
The measurements I made for the stand are for my Vox Cambridge Twin Reverb amp that measures 22.5inches x 9inches x 16inches and weighs 40 lbs.
I'm pretty sure most combo amps will fit on this stand.
Step 1: Materials
20 feet PVC pipe (I only used 15 feet)
4 pairs of PVC elbow connectors
5 pairs of PVC T-connectors
Step 2: Back and bottom support for the amp and bottom frame layout
I then laid out the elbow connectors to see where the bottom frame support will be.
Step 3: Assembling the middle part and getting the tilt
Step 5: Bottom frame and back supports
Made a minor adjustment to one part, since it became short when the bottom frame got completed.
Step 7: Glueing parts together
I also found it easier to assemble them from right to left.