L2A Assembly Guide

Safety Precautions, Warranty, and Disclaimer Improper soldering and handling of electricity can cause serious injury and damage to your property. Read and understand the instructions below before beginning your project. Follow the instructions, build carefully, and use the appropriate tools. Build at your own risk. DIY Recording Equipment, LLC is not responsible for any damage or injury resulting from the assembly or use of your kit. You are the manufacturer of your kit. It is your responsibility to turn this group of parts into a working piece of recording equipment. DIY Recording Equipment, LLC does not guarantee the success of your project and disclaims any Implied Warranty of Merchantability. Please visit the support forum for assembly support.
Damaged or Missing Parts All kits and parts are checked before being shipped to you. If something arrives damaged or if your kit is missing a part, please open a support ticket to inquire about a replacement. Missing parts will be replaced at our expense. Damaged parts should be returned for verification. If the part shows signs of use beyond what was necessary to determine that it was damaged, DIY Recording Equipment, LLC reserves the right not to replace the part.
Welcome to the L2A assembly guide.

Thank you for purchasing a L2A Re-amplifier Kit!

This guide is for the L2A Rev E, launched August 2021. If you have an earlier version, head over to the L2A Rev D Assembly Guide.

If this is your first DIY project ever, we recommend reading our Getting Started Guide.

Required Tools top

Soldering Iron
We recommend an adjustable-temperature station, such as the Weller WLC100.

You can use 60/40 "leaded" solder or lead-free. We recommend 60/40 because it flows better and is easier for beginners to use.

Wire Cutters
You'll need a pair of good "snips" for cutting of the excess leads after soldering.

Phillips Head Screwdriver
A #1 Phillips head screwdriver.

Optional Tools top

If you run into problems, a multimeter can come in handy. You can also use it to sort resistors.

Desoldering Pump
If you accidentally solder something in the wrong place, a desoldering pump can save the day.

A bit of clear tape will help hold some tricky components in place for soldering.

Resistors and Capacitors top

Bend Resistors top

Bend the resistor leads 90 degrees at the body so they can be inserted into the PCB.

Sort Resistors top

Resistor sorting made easy! Enter a value to find the color bands, or enter your color bands to find the resistor’s value. Type in the value of the resistor you need and this tool will show you the corresponding color code.

Place Resistors top

Place the resistors into their respective positions on the PCB. As you place each resistor, bend its leads against the bottom of the PCB so that it stays in place during soldering.

Solder Resistors top

Solder the resistors to the PCB. Observe good soldering technique: heat the pad and lead for 2-3 seconds, apply a small bit of solder, and continue to heat the pad for another 2-3 seconds. The finished joints should be shiny and should have just enough solder to cover the pad entirely.

Trim Resistors top

Use clippers to trim away the excess leads. Clip as closely as possible to the joint without clipping the joint itself.

Populate Small Capacitors top

Place the smaller capacitors in their respective places. These capacitors are not polarized and therefore can be placed in either direction. Solder then trim the leads.

Transformer top

Place Transformer top

Place the transformer on the PCB in the area marked "X1 / 10K/10K." Note that there's a small notch in the plastic near pin 1. Line this notch up with the corresponding one on the PCB. Then solder the transformer to the PCB. To prevent damaging the transformer, leave 20 seconds between solder joints. This allows the coil wires time to cool down between joints.

Panel Components top

Populate Potentiometer top

Place the potentiometer. Bend the two outer leads against the PCB, then solder and trim.

Populate TRS Jack top

Remove the nut and washer from the TRS jack and set them aside. Place the TRS jack. Hold it in place with tape or by bending the leads, then solder and trim.

Populate Combo Jack top

Place the combo jack. Lay the jack on it's back with the PCB lying on top of it to solder. Solder the metal pins of the jack but do not trim the leads.

Place Switches top

Place the two toggle switches in their respective positions and bend the leads, but do not solder yet.

Attach Panel and Solder Switches top

Attach the input panel over the switch and XLR jack, and screw the panel to the XLR jack. Since these screws are cutting their own threads, you'll feel some resistance the first time you put them in. Make sure that the switches are sitting nicely in the panel, then solder and trim the leads.

Case Assembly top

    Before putting case together, check the following things:

  • Resistors: Are all the resistors in the correct positions?
  • Soldering: Is every solder joint shiny and clean? If one is cloudy or misshapen, try reheating it for 8 seconds and adding a tiny bit more solder.
  • Trimming: Are all of the excess leads trimmed down as close to the joint as possible?

Slide PCB into Case top

Slide the assembled PCB into the lower channel in the case. The input panel should be on the side of the case nearest the "L" in "L2A."

Fasten Panels to Case top

Screw in the eight mounting screws. It's a good idea to install all four screws on one panel loosely before tightening each one.

Fasten TRS and Potentiometer to Case top

Fasten the TRS jack and potentiometer to the case with the included washers and nuts.

Install Knob top

Set the potentiometer to the middle position (10 clicks). Then place the knob over the shaft and orient it so that the indicator line faces 12 o'clock. Then fasten the knob to the shafts by tightening the set screw with the included hex wrench.

Apply Foam Pad top

Remove the backing from the foam pad and apply it to the bottom of the case.

Testing top

Send Audio to L2A top

The L2A accepts a balanced input via the XLR/TRS combo jack. Run an XLR or balanced 1/4" cable (TRS, two stripes on plugs) from a balanced ouput on your audio interface to the LINE INPUT. Then send a signal to that output with your DAW. The signal can be anything—whatever you want to hear the first time you plug in your L2A!

Connect the L2A to a Guitar Amp top

First, turn the LEVEL control down completely (counter-clockwise). Then run an unbalanced 1/4" (TS, one stripe on plugs) from the OUTPUT to a guitar amp. Turn on the guitar amp and slowly increase the level of the L2A. If you hear your audio signal clearly through the speaker, your L2A is working correctly.

Check the Switches top

While still playing audio through the L2A, check the filter positions. With a wide-bandwidth audio signal such as a guitar playing chords, you should clearly hear the high- and low-pass filters.

Then switch between the LIFT and GROUND positions. With some setups one position will be noisier than others, while in other setups the switch will not make a difference. When in doubt, the preferred position is LIFT. If you don't hear a difference, don't worry—the switch may come in handy someday with a different amp.

Finished! top

All good? Congrats on finishing your build! Have a question or problem? Drop us a line.

Help Us Improve top

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