PR502 2.0 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 PR502 assembly guide.

Thank you for purchasing a PR502!

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 a problem needs solving, 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.

Component Sorting Sheet top

To identify and keep track of every part in the kit, download and print the Component Sorting Sheet (PDF).

Check Revision Number top

This guide is for the PR502 2.0, released January 2020. For earlier versions visit the PR502 1.x Guide.

Resistors and Diode (Bag 1) 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 Diode top

Place the diode so that the line on the component matches the line on the PCB. Double check the orientation, then solder and trim.

Capacitors, LEDs, Switches, and Inductors (Bag 2) top

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.

Insert LEDs top

Place the LEDs, inserting them as far as the flat parts of the leads.

Polarity: Place the longer lead in the "+" hole.

Bend and Solder LEDs top

Bend the LEDs forward to where the rear panel will be, then solder and trim.

Populate SCR (U1) top

Place the SCR in the U1 position. Make sure to align it so that the silver metal part on the body aligns with the stripe on the PCB. Check the orientation, solder, and trim.

Populate LINK Header top

Place the 2-pin, LINK header with the longer leads facing up. Then place the 2-pin shunt over the pins and solder. You may need to use a piece of tape to hold the header in place for soldering.

Install Switch Cap top

Press the cap onto the switch.

Populate Switch top

Place the switch and use a small screwdriver to bend a couple of the leads against the bottom of the PCB. Solder and trim.

Populate Inductors top

Place the inductors in their positions, solder, and trim. Inductors are not polarized.

Quick Question top

Are you using the component sorting sheet?

Yes No

Populate Large Capacitors top

These capacitors are polarized, so they must be placed in a certain direction. The positive lead is slightly longer, while the negative lead is marked with a stripe on the body of the capacitor. Place the capacitors with the positive lead in the pad next to the "+" marking on the PCB. Double check their orientation, then solder and trim.

XLR Jacks and Standoff (Bag 3) top

Populate XLR Jacks top

Place the XLR jacks. Most will snap in place, but you may need to use some tape if they fall out before soldering. Solder the jacks but do not trim the leads.

Populate Standoff top

Place the long screw through the bottom of the PCB, then thread the two standoffs onto it from the top.

Card Edge Connectors (Bag 4) top

Install L-Brackets top

Place the brackets on the underside of the board as shown. It may be hard to see, but one end of the L-brackets is longer than the other. Fasten the longer end to the PCB via the short, silver screws from the top side of the PCB.

Populate Card Edge Connectors top

Place the card edge connectors through the side of the board labeled J7/8. Press the connectors down so they sit flush with the board. Solder the card edge connectors to the PCBs and trim the leads. Make sure to solder on the side that has no labeling.

Attach Card Edge Boards to Motherboard top

Place the shorter, angled pins of right-angle headers in the CON2 and CON3 positions through the bottom of the board. Then place the card edge board over the longer pins so they protrude through CON3/4. Then fasten the card edge board to the motherboard with the black screws.

Solder Headers top

Solder the headers to both the motherboard and card-edge board. Then trim the excess leads from the card-edge board.

Chassis (Bag 5) top

Attach Rear Panel top

Screw the rear panel to the XLR jacks. Place the lock washers on the lower screw hole of each jack.

Attach Side Panels top

Screw the side panels to the rear panel using the shorter, pan head screws.

Insert Top and Bottom Panels top

Slide the top and bottom panels into the channels in the side panel. Orient them so that the vents are near the rear panel.

Attach Front Panel top

Screw the front panel to the case using the flat-head screws.

Final Checks top

    Before you wrap up, check the following things:

  • Capacitor orientation: Is the stripe on the cap on the opposite side from the "+" marking on the PCB?
  • Diode orientation: Do the stripes on the diode match those on the PCB?
  • 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?

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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