- This topic has 1 reply, 2 voices, and was last updated 1 year, 7 months ago by Lloyd-ss.
May 17, 2016 at 11:00 am #1197Glen v AModerator
The number one service call we get for the Cortado is “I get no signal. I must have fried the FETs. Please sell me a new pair”. (We have heard this maybe five times with hundreds of Cortados sold.) If the FETs are damaged, you will likely still hear SOMETHING getting through the circuit. It will sound faint, or constrained, like the signal can barely push its way through the circuit, but you WILL hear SOMETHING. If you hear NOTHING, the problem has always proven to be issues with soldering. Carefully make the rounds of the circuit with a tester, looking for points that should not be grounded but are. Measure the resistance across each resistor; if you see something far off the value listed right on the circuit board, investigate further! (The exception is R8; some boards display 1K5, or 1.5kOhm, but may be equipped with a 680R resistor.) It takes only a tiny particle of errant solder to bridge points on the board that should remain isolated. If you are over 40 years old, you probably need help seeing these things. (I am 52 and cannot solder at all any more.) Ask a younger friend to inspect your board for you, or take clear, high resolution photos under direct sunlight of both sides of the board and email them to @zeppelindesignlabs.com">email@example.com. We will take a look and recommend areas that you should clean or re-solder.June 19, 2018 at 7:34 am #3804Lloyd-ssGuest
Glen, I had to chuckle at your eyesight comment. I am well past you in years, and have been using a large magnifying light for close work for a long time. It makes it easy to see how crappy those solder joints are that looked ok to the naked eye, LOL.
I’ve been studying the various comments for when my kit arrives in a few days. Thanks for the thoroughness of the answers, and kudos to the SUPERB job on writing up the assembly instructions for the mic and preamp. You are setting your purchasers up for success when you provide that kind of support. I’ll let you know how things go with the tap dance setup.