This is a review and detailed measurements of the Pyle Pro PP444 phono preamplifier. It is on kind loan from a local member. The PP444 costs US $12.99 from Amazon with free shipping. No, you didn't misread it. It is actually just $13 including free shipping.If you are not familiar with Pyle brand, it is the name that goes on cheapest of cheap audio products. I associate it with junk and to-avoid but let's find out if the PP444 is an exception.From the outside, the PP444 looks like other bargain audio products:The box is solid enough given the price range.One look at the external switching power supply though tells you corners were cut. There is no regulatory/safety marks on it whatsoever. Worse yet, as I tried to unplug it once, one side actually caved in. So they even skimped on glue to mate the two halves. As the line in Adams Family goes: "be afraid, be very afraid" when using this power supply. Your life could literally be in danger.Let's put the thing on the bench and see what comes out.Here is our usual dashboard with 5 millivolt input to simulate a moving coil input:SINAD (signal over noise and distortion) is completely dominated by mains hum at 60 Hz. Now, this is common and usually I can remedy it some by playing with grounding. But here, that peak would not move a millimeter no matter what I did. So I ditched the power supply that it came with and powered it with my lab supply:Look at the radical reduction in mains hum and the rest of the noise spikes that were there. SINAD as a result improves a bunch to 65 dB.Is it good enough now? Not really. See the frequency response:The response starts to drop from 2 kHz on down. By 20 Hz, you are have lost 3.5 dB.Thinking something may be wrong with my setup, I replaced the PP444 with DJ Pre and got the sane response in dashed teal. So the PP444 is that messed up. If you use it, don't be surprised that your bass is gone or alternatively it sounds bright.As a last test before I could not handle it anymore, I ran a distortion+noise versus frequency measurement:As you see, even with my lab supply we are talking pretty elevated levels of distortion and noise.Do I need to spell it out? You paid very little but in return potentially put your life at risk with a non-certified switching power supply and copious amount of mains hum and noise. Maybe the LP grove noise and pops/clicks mask it. I don't know. What I do know is that I would stay far, far a way from this phono amplifier. You can pick up proper phono stages for the price of a dinner or two.------------As always, questions, comments, recommendations, etc. are welcome.FOLKS: if I die of depression due to all these poorly performing audio products, it will be on your hands! Don't let me sink too low by cheering me up with