Soldering Musikding "Der Acapulco" overdrive kit

I took advantage of the winter holidays to solder and assemble “Der Acapulco” overdrive pedal kit from Musikding.de. The pedal is a clone of the “Acapulco Gold” pedal from EarthQuaker Device, which is itself based on the power section of a vintage Sunn Model T amplifier. The circuit is very simple, it consists of two LM386 op-amps in series and a single large knob to adjust the volume.

It was my first soldering experience, and I must say that it was not difficult, once you acquired a minimum of soldering technique and found the right combination of solder and soldering iron temperature.

General soldering tips

• This HackMakeMod video is the best soldering tutorial I’ve found online
• I was happy with 0.5mm solder wire, 60/40 lead-tin
• Using the video table I set the soldering iron to 370°C
• The best soldering technique I’ve found so far is:
  1. touch the tip of the soldering iron to the metal base of the hole and the leg of the component
  2. bring the solder wire close to the point where the three elements touch
  3. let the solder melt for a few seconds (the amount is learned with experience)
  4. remove the solder wire, leave the soldering iron for a few more seconds
  5. after the solder has flowed into the hole, remove the iron

At first I had trouble making clean solder joints with the classic inverted cone shape, but I was using a solder wire too large, with a melting temperature too high and I was keeping the soldering iron at a low temperature. Once these three parameters were adjusted, it was much easier to make soldering joints like those seen in online tutorials.

Specific advice for “Der Acapulco”

In the kit, even if the enclosure is included in the order, there is no knob for the potentiometer. It must be added separately to the order, otherwise, like me, you will be forced to order another pedal kit and an extra knob.

Like most guitar pedals, the input jack is on the right and the output jack on the left. At my first power-on test I thought my pedal didn’t work, but I had only reversed input and output.

The footswitch has no direction, you can only mount it on the daughter board with the pins aligned horizontally, but you can swap the top with the bottom with no consequences.

When the instructions say that the LED must have the long pin on the right side, it means on your right side while looking inside the enclosure. the long pin must go in the hole on the board indicated with the +.

When soldering capacitors, the positive side is indicated on the board with a +, while on the capacitors themselves, the negative side is indicated with a light band, so the light band must be soldered opposite to the +.

Resistors do not have a direction, they can be soldered in both directions, as well as the ceramic capacitor, the one indicated on the board as C4.