This is a review and detailed measurements of the Sony HAP-S1 digital player, server, streamer and integrated amplifier. It is on kind loan from a member and costs USAD $998 on Amazon including Prime shipping.I must say, having worked for Sony years back (1990s), I still have a soft spot for the company at some level. So keep this in mind as you read the review.From the outside, the HAP-S1 looks pretty nice:There a lot of features here from internal storage of music on 500 Gigabyte hard disk (as shown) to network streaming. I am not going to review any of that. I suggest reading the write-up on Archimago's site for that (and painful limitations within): http://archimago.blogspot.com/2018/05/review-sony-hap-s1-by-allan-folz.html While the LCD is nice and larger, don't expect mobile phone class performance and smoothness when it comes to scrolling and such. Mind you, it is not horrible but it is the typical slow microprocessor struggling to move pixels smoothly.I had no issues navigating the menus using the rotary control which has a switch to select options.The volume control though, is horrid. It is so stiff and you may need to go and get a large pair of pliers from hardware storey to turn it! As if they thought by making it stiff it will feel luxurious which it does not in any form or fashion. The control is digital and has pretty large steps. And oh, when you first turn on the unit, the volume control works for for good few seconds, you get no indication on the screen as to its value! Seems to be a software app that takes a while to start after the unit powers on.Connectivity in minimal:The "line out" is actually not line out. It is DAC out. Nothing from analog inputs gets routed there.Very strangely, there is no USB input! There is USB host interface for a thumbdrive and such but no way to use this as a USB DAC.Let's get into measurements and see if she lives up to Sony brand of yesterday or not.For DAC measurements, I fed the HAP-S1 using S/PDIF and measured the output using the D/A output. Its level is fixed and slightly above 2 volt we like to see:Yuck. 84 dB SINAD (Signal over noise and distortion)??? Sony goes out of its way to advertise this as a high-resolution player and it can't even do justice to 16 bit CD (dynamic range of 96 dB)?No, it is not any kind of digital clipping. Lowering the level -1 dBFS only improved SINAD slightly. Distortion is dominated by the second harmonic.Needless to say, this type of performance puts the HAP-S1 in the tier 4 (lowest) of all DACs tested:Jitter performance could be better but not an audible concern:The spikes on the left are power supply noise which you can also see in the FFT in the dashboard. I tried to lower then by playing with grounding but only got this far.Linearity is not bad but definitely fails us as far as high res content is concerned:We have $99 DACs that are nearly ruler flat here to -120 dB (20 bit performance).THD performance usually predicts Intermoduation distortion and this is no exception:We have elevated noise and distortion that dominates at around -13 dBFS.Multitone test dramatically shows the problem with high harmonic distortion we saw in dashboard:I think this is the worst performance I have seen since I started to run this test. Higher frequencies in real music are at much lower levels and likely will get swamped by the spray of harmonic distortion from lower tones. High-res promise forgotten for sure.Let's take some bets before I show the headphone measurements. Who thinks they are going to be good or bad? Let's find out.Here is what we get with 300 ohm load:Wow. That is incredibly high noise level. There is good amount of power though which "smells" to me that they output is coming from the power amp and hence the much higher noise level.Let's see what happens when we reduce the load to 33 ohm:Crap is what happens. We lose a ton of power. Usually we get more power when we go down in load impedance. Not here. We are left with incredibly low 45 milliwatts of power. I suspect your phone puts out more power than this desktop product. What is wrong? This is what is wrong:Yup. We have 400 Ohm output impedance! So our suspicion is correct. They did not design a dedicated headphone amp. Instead, they put a 400 ohm resistor on the output of the power amplifier and called it done. Never mind that we now have huge losses and impedance that will likely change the tonality of most headphones you throw at it.You could have predicted this book by its cover (DAC measurements), could you not?Can the power amplifier save the HAP-S1? Let's find out.Let's start with our usual 5 watt dashboard. I used the S/PDIF digital input:0.03% distortion? Why would anyone care about high-bit-depth content on an amplifier that can't remotely resolve 16 bit content? We are 50 dB short of resolving 20 bits!Even if the harmonic distortion was not there, all of those mains harmonics would have gotten us.Frequency response is flat enough for CD playback but for high-res we have some peaking which an be forgotten:Sony does not spec the power level at 4 ohm. This is what I got:Not bad as far as power goes for a desktop amp but as expected, noise level is pretty high. Best case performance is 0.01% THD+N (really +N). Should be good enough for small desktop/bookshelf speakers.I think we need to stop punishing ourselves and stop here.To say the Sony HAP-S1 has disappointing performance is an understatement. There is not one subsystem that is designed for excellence. You can tell no one cared for was proud of the audio performance since the "specifications" on Sony site has essentially no data. The engineers that designed the good Sony gear back in 70s, and 80s must be long retired by now. Morita-san (co-founder of Sony), may he rest in peace, would have a heart attack over what this HAP-S1 produces.The engineers are not the only ones at fault. The marketing department is to blame too for demanding a list of modern features, forgetting what it means to build an audio product with Sony name on it. Clearly they are out of touch not realizing the importance of good headphone amplifier design for example.The amount we have regressed in audio performance over the years is astonishing. Companies have forgotten where they have come from and what their brands stood for. It is not like they can compete with software giants like Apple. The least they can do is build great performing hardware. The guard is asleep, leaving it to "chinese" companies to build state of the art desktop audio products. Imagine the shame in that. I hope there is a serious wake up call at Sony.Now please excuse me as I go and edit out Sony out of my resume.------------As always, questions, comments, recommendations, etc. are welcome.Have craving for some good Dim Sum. Nearest place is 35 miles away so I need gas money for that. Please considermoney using: https://www.patreon.com/audiosciencereview ), or https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ).