L2A Assembly Guide
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Table of contents
- Required Tools
- Optional Tools
- Resistors and Capacitors
- Bend Resistors
- Sort Resistors
- Place Resistors
- Solder Resistors
- Trim Resistors
- Populate Small Capacitors
- Place Transformer
- Panel Components
- Populate Potentiometer
- Populate TRS Jack
- Populate Combo Jack
- Place Switches
- Attach Panel and Solder Switches
- Case Assembly
- Slide PCB into Case
- Fasten Panels to Case
- Fasten TRS and Potentiometer to Case
- Install Knob
- Apply Foam Pad
- Send Audio to L2A
- Connect the L2A to a Guitar Amp
- Check the Switches
- Help Us Improve
Required Tools top
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.
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.
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.
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:
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.
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.