Building a tubescreamer 2/3

Here's the part that I said was harder than building a tube amp - the size! This little chassis (the size is called BB) will have three knobs, a foot switch, a power indicator, an input jack, output jack, external power supply, and three switches (popular mods to the TubeScreamer model). Oh, and I almost forgot that I need room for a battery on the inside! This is not as many holes as an amp chassis - but I bet the number of holes per surface area is more than double that of a tube amp!

Since everything is so cramped, I would drill a few holes, load up the components, test things for fit, and then remove everything to drill a few holes. I really love drilling out this kind of stuff. Knowing that the controls will be exactly where I put them requiring a lot of layout is a fun challenge. Besides, I never took metal shop in the eighth grade like the other guys (I think I took Spanish I). Here's making up for lost time!

I had to change my soldering iron to a needle-like tip for this close work. I think the next time I do this I will get one of those hobby items that has a magnifyng glass and something to hold your work up - I can definitely feel my eyes getting older doing this kind of close work. To do this part, you feed a component up from the top, and solder it here on the back. It's pretty straight forward (unless you lose yourself, which only happened 2-3 times). This probably took about 30 minutes to populate the circuit board - not too bad.

Here you can see that I started with some of the larger components first. I have seen recommendations to put the smaller stuff on first - but I follow this advice. The IC socket just has to go where its supposed to - and the larger capacitors also claim their own geography first. Here's one thing that bugs me about these little circuits - if I make a mistake it seems like it would be so hard to trace. With an amp you can really visualize how things are laid out in the larger chassis and the turretboard. You can trace the circuit by following the wires. Here, there are no wires, just circuit traces, and they are on the back. I just better get this right the first time because I don't feel like debugging something like this. (But, I have to admit, making a mistake, debugging, and finding it later is still a fun process and part of the whole experience.)

Okay, this looks horrible, and is a little deceiving. I built this fx pedal before I painted it (not what I do with tube amps). I guess I wanted to know if this thing actually worked before I spent time painting up a fancy box before chucking the whole project in the trash (and never blogging about it!). So, I had a working effects pedal and then took it apart to paint it. This is all the components taken out of the chassis and it gives the false illusion that I built it this way. This is close work, and hard (but not that hard!).

Here is the the chassis after being primed and painted with a flat white. As you can see, I have decided on a Bob Saget theme for this little guy. I am planning to give this one to my son after I'm done so he will be stuck with God's gift to comedy permanently adorned to his TubeScreamer. Of course, I have already tested this thing and it sounds absolutely awesome. So, I don't think he will mind. Drawing Bob Saget from my template may be a challenge. My first attempt on scratch paper looked like a young Bill Clinton.

I will then build a second one, after I work out the layout kinks. Of course I will need to pick another celebrity or image for that build.


--gh