***CORTADO MKII TROUBLESHOOTING GUIDE***

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I am posting some technical details here to aid in troubleshooting the Cortado MkII circuit.

If you are having any trouble with the circuit (or the mic in general) the first thing to do is make sure the all voltages around the circuit board are within range. Use this graphic to test these points. Measure against ground…which means your meter’s red probe is testing these points while the black probe is on a common ground point, like the chassis (if it’s properly grounded), or pin 1 of the XLR jack (labeled “XLR1” on the pcb), or one of the unused holes in the corner of the PCB. The board needs power when you take these measurements…so plug it into phantom power.

Testing all these voltages should get you pretty far into figuring out what might be wrong. These voltages can be “off” by 5% or so (which depends on the characteristics of the FETs in your kit), but they should be in the same range relative to each other.

By far, the most common problem we see with non-functioning Cortados is bad solder joints. Please make sure your kit’s solder joints are good and solid…but that is easier said than done, especially if you don’t have much experience soldering, or don’t even know what a good solder joint looks like. In this case please look up some good Youtube videos on how to solder on hole-through components on circuit boards. But knowledge will only get you so far because soldering is a skill, so it also helps to practice. When I was learning to solder, I would take apart old, broken electronic equipment and practice soldering on those circuit boards…I encourage anyone who needs practice to do the same.

Soldering Pro Tip: Use small diameter solder…it’s much easier to control and not get too much solder on each joint. The solder we use is .031″ (.8mm) wide. Also use good quality, rosin core solder…”Kester” brand is the best and most reliable (IMHO).

The second most common problem we see is issues with the piezo disc. Piezo discs are very fragile and hard to solder to, so it can be difficult to get and maintain a good electrical connection. The main problem we see with these discs is that they end up cracking in assembly. Fortunately, a cracked disc will still (partially) work, and you may never even know it’s cracked. But if the disc is under the right kind of pressure the crack may worsen and the signal may start cutting out or “popping.”
One of the big things we see is when the customer puts too much strain on the cable, near the piezo disc. Often times the solder joint between the cable and ceramic part of the disc can start cracking and pulling the ceramic off the disc. You’ll start hearing “popping” and distorted sounds when the cable is barely moved. If this happens to you, the only thing you can do is start over with a new disc and shielding tape. Cut off the old disc, strip the cable wires and re-attach a new disc with a grounded shield. Don’t try to remove the tape from the disc, it will just get worse…the only thing to do is replace it.

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