NOYITO 12V High-Fidelity Microphone Pickup Module Noise Reduction Microphone Amplifier Board High Sensitivity Kit - Adjustable Sensitivity

I replaced the mirror (with integrated microphone) of the Ford 2009 Escape - leaving me without a microphone. I installed this unit in the overhead light assembly and drilled a small hole for the mic. Worked perfectly without adjustment and provided a clear noise-free microphone for hands-free phone calls. Pay attention to the reversed power and ground wires on the power connector! I switched the wires at the connector so that the wiring into the truck was correct.

I bought two of these condenser microphone preamplifiers in preassembled form to save me the time of having to assemble them. The first thing that I noticed was the polarity of the power supply connector and the polarity of the audio output connector. They are polarity opposites. The matching connectors that were furnished were of correct polarization for one of the preamplifiers, but for the second preamplifier, I ended up with two connectors with the positive lead to the right. It isn't a problem as long as it is noted and the cross connection is made. I haven't run any audio sweeps on these preamps, but intend to do so. Eventually, I intend to replace the integral condenser microphone with a condenser boom microphone since there is voltage present on one of microphone pins for the required condenser microphone DC bias voltage. The volume control on the preamp board works nicely to control the output amplitude. The preamp is powered with 12VDC and no other regulated voltages are required. The preamp chip is the ubiquitous 5532 IC

It worked as expected for the money, I needed more control for the volume, I tide it in with the Drock TDA7297 powered amplifier and it worked great for under $20.00.

After examining this preamp I did not even bother powering it up. I expected this to be a basic design found in any elementary design text, or even Google! But no, instead it's some nearly random collection of parts. So here's a fairly technical overview. Sigh, so where do I start listing the design problems? Several other reviewers had already noted the reversed red and black wiring on the power connector. I could live with that. Excessive decoupling on the microphone biasing, I could live with that too. But, incorrect biasing on the first op amp stage, and a pot that can take the gain negative. Op amps don't like that. The designer wasted the second op amp stage as a unity gain buffer. Should have spread out the gain structure between the two. But maybe that's just as well; two poorly-biased stages would be worse than one! A strange resistor R8 to AC ground. Is the first op amp unhappy and this is a fix? The photos show the "NE5532" IC in a socket. Nope, mine was soldered in. Huh, "NE5532" is in quotes? Yep, last but not least, the IC is a counterfeit, fake part! This is because there are no input protection diodes which the real parts have. Quite strange as genuine NE5532 are not that expensive, and the seller wants nearly US$9 for this preamp board. Here's the not-surprising ending: I am returning this preamp board for a refund!

Actually quite disappointed. Couldnt figure out why it wouldnt work right from the beginning and would produce a major hum when connected to any amp. Then upon further inspection it turns out the power connector is wired backwards from what the board silkscreening says. So its been shorting out my power supplies with the protection diode on it. That's the kind of mistake I'd expect to find on a cheap eBay module not from someone selling on Amazon. Quality control would be nice from the manufacturer.

As others have written, the power cable is backward as opposed to the industry standard of Red being positive VCC and Black being Ground. I guess this doesn't apply in this case. So be careful. The two center pins are grounds. Also, the chip is soldered to the boards instead of the picture clearly showing it's socketed. Luckily, it does seem to work fine so far.

connected red with black and black with red ,but both did not work ,not even a sound with 9,5 ,12 volts ,so now what ?

This is a cute little device. You'll probably notice right off, but the positive lead is black and the negative lead is red.