Designing A Tube Guitar Amp: Part 8

el84_cabinet_sketchupCabinet Design

At one point in time, I wasn’t that great at designing cabinets. Even after creating several cabinets, I still have manufacturing defects in every finished product. the best cabinet I ever built as far a quality goes was the one that was covered in fuzzy carpet and had the corners covered with plastic edges. As I get more advanced with cutouts, I’m doing better at some things, and I’m still making mistakes while learning the new skills.

The cabinet design that I chose for this amp was similar to the 5E3 amp cabinets, but I wanted mine to be slightly smaller. Hindsight being 20/20 on this: I could have probably opted for a slightly larger cabinet; The parts (speaker and transformers) are going to be in very close proximity to each other. When I say close, I mean dangerously close. When all is said and done, there will only be a few hundredths of an inch clearance unless my estimates are off a bit. I’ll really find this out once I purchase the parts and start my dry fit.

I originally drew this cabinet to match the dimensions of a cabinet that I found in a Google search. Using Google SketchUp, I made each part of the cabinet and then fit them together. I decided I wanted to have a smaller amp, so I shrunk the dimensions and moved some stuff around. Even the image above has some parts in the wrong place. When I moved stuff the last time, some holes were shifted in the wrong direction. I didn’t let this hold me back. I went ahead and built the cabinet despite my drawing being a little off. I had a clear enough picture of what I wanted that I could make the final calls with the saw in hand. I was sure to measure more than once before cutting.

This is another one of those tasks that drawing it by hand might be easier than trying to figure out how to use a CAD program. If you do draw by hand, be sure that all of your measurements are logged. Do the math to make sure everything works out fine. you’ll still have to do this even if you use a computer to do the drawing for you.


  • Speaker diameter and depth
  • Chassis mounting points
  • Clearance given by parts on bottom of chassis
  • Baffle sizes
  • Plywood dimensions
  • Handles, feet, casters…you’ll want these!
  • Tube locations…think “HEAT!” Keep ventilation in mind.


About robbie

I am an electronics enthusiest and a ham radio operator (W1RCP). I like to play with electronics. It's fun and educational. I looked forward to working in the engineering field in the future. I have a BS in Electronics Engineering Technology from DeVry University. I also have an Associate's degree in Marketing Management from Moultrie Tech, and a diploma in Electronics from MTC.