This is a review and detailed measurements of the STR-DH190 stereo amplifier. I was talked into buying it to review a while back. The STR-DH190 costs an incredibly low US $140 from Amazon including free shipping! The economics of this is impossible to fathom. If I had to sell you its empty box I could not make a living at this retail price. So I imagine Sony is losing money on every one of these.From the outside, the STR-DH190 looks like a smaller version of Sony AVRs with a rather elegant look:I did not expect a full display and microprocessor to drive it but that is what we have. Likely because this is a featured AVR. Everything looks great until you touch the volume control and realize it is a stiff feeling thing, best left to look at than use. Fortunately a remote control is included so you can do exactly that.You even get a radio and phono stage in this thing. And even a button named "pure direct" which did nothing but turn off the display.The back panel shows the connectivity you expect in an analog amplifier:I hated the spring loaded speaker terminals as I could not stuff my banana plugs into it. But hard to complain too bitterly at this price. Ditto for non-removable cord.There is a "hot" symbol on top of the amp for a reason: even at modest output power this thing gets really warm and toasty on top. For this reason, and wanting to pass UL certification with respect to heat generated, Sony only specs the STR-DH190 for 6 ohm speaker load and higher. Don't worry, it works "fine" at 4 ohm as well as my measurements show.As a sign of corners being cut to save money, notice how the rear feet are just the chassis bulge with a tiny little pad. The front feet that you do see are proper round plastic ones! Reminds of stainless tips on car exhausts to make you think the rest is made the same way.Let's run our dashboard with 4 ohm load and 1 kHz tone and see what happens:Typical power supply ripple is visible which we see in many amplifiers. I wish both channels were as good but they are not with one having good bit more distortion than the other. Averaging the SINAD for both channels lands the STR-DH190 in the middle of all amps tested with this metric:Signal to noise ratio is "OK":Frequency response measurement had me stomped for a while because it was anything but flat. There is no eq in this thing so what could it be? Then I realized it was the amplifier that was reducing power after a few seconds even though I was just running it at just 9 watts or so! You can see that in the top graph:The sweep starts from right and goes to left and hence the reason you see the drop there. Running the same test with 5 watt output didn't cause that problem. But showed the same persistent rise in low frequencies.32-tone test track shows what we already know as far as distortion floor:At low frequencies power supply complains with rising ripple causing those spikes between our tones. At high frequencies the amp runs out of gain-bandwidth so distortion naturally rises some.Most important here is the power versus distortion and noise so let's look at that with an 8 ohm load:We just shy of the 100 watt rating of the amplifier which is fine.With 4 ohm load we get lots more power still:Again, wish one channel wasn't acting up but otherwise, we have lots of power here.We can even get more if we measure max and peak power with 1% distortion into 8 ohm:Couldn't run this test at 4 ohm because the amp would either shut down or when I reduced the level, not achieve 1% THD. More on this in a bit.THD+N versus level and frequency shows orderly response, had it not been due to each channel acting differently:At this point, I decided to run the 20 to 20 kHz power sweep, regulating the output to 1% THD. This involves the analyzer at each frequency point, raising and lowering the input level until distortion equals 1%. I kept failing to get there at all frequencies with the amp shutting down or not getting to high enough distortion. Needing to play with the parameters a lot, I put a fan on top the amplifier heatsinks and kept playing around. Next thing I know, it shuts down but no longer powers up. The power LED lights up but the rest of the display does not. And after about 8 or so seconds, it shuts itself down.Left it to cool overnight but this morning still does not power up. Nothing is smoked in there but there is a smell of burnt varnish which points the finger likely at the power transformer.Lowing our lofty standards good bit, the Sony STR-DH190 seems to be a good amplifier. It looks nice, has remote, multiple inputs, phono, etc. and produces a lot of power. It is certainly much better than a lot of Internet specials when it comes to amplifiers. What you pay for it gets you headphone amplifier and that is it. The value is therefore remarkable.The beheaded pink panther is making a showing here naturally due to the unit failing. The protection circuit should have saved this product but it did not. Likely it doesn't look to the power supply getting overburdened. Now I have to figure how to get this unit serviced. If they tell me to ship it to them at my expense, that will be the end of this journey as it wouldn't be worth the cost or aggravation. We do have a Sony repair center about 40 miles from here but who wants to drive back and forth and wait for who knows how long to get this fixed?Of course, I waited months to test this so can't return it to Amazon where I bought it.I suspect none of you will stress it to the extent I did though. As a back up if you drive it hard, you may want to get one of those fan coolers and put it on top.No recommendation one way or the there. You have the data to decide.------------As always, questions, comments, recommendations, etc. are welcome.The "talent" fees are double the usual amount due to the need to hire two panthers for the product shot. So, appreciate you allgenerously so I am not out that fee on top of lost $140 for this amplifier using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/