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    Musical Fidelity Nu-Vista 600.2 Integrated Stereo Amplifier Preview

    Built on the same platform as its bigger sibling, the Nu-Vista 800.2, the slightly paired down Nu-Vista 600.2 offers a Class A tube stage consisting of highly famed Nuvistor tubes. The Nuvistor tubes were mass produced in the late 50s and early 60s and are known for their robustness and low noise and distortion. They were used in many applications due to their small size and durability. This Musical Fidelity integrated amplifier is analog only, which fits into the company’s philosophy that the best sound in audio is analog, and the best analog reproduction is with Class A amplification. The Nu-Visa 600.2 boasts 200 watts per channel at 8 Ohms, it’s designed to give the performance of its bigger sibling, while being more suitable for smaller rooms. The Nu-Vista 600.2 has the same casework as the 800.2 which is massively built. It is heavy with solid metal face plate and heat-sinks. It lacks a few more watts per channel and shaves off a few pounds, but it is still a beast at almost 80 pounds. I needed help getting it up 19 steps to my media room (thanks, wife). It exudes luxury in both looks and feel. The front panel display can show input source and volume, or be used to display live time VU meters that can be clearly seen from across the room. I live in an almost entirely digital world, but I was able to use the high-performance DACs in my Onkyo to feed the Nu-Vista 600.2 a clean analog signal from my streamer. The better your DAC, the better your analog output and the better the analog feed to the 600.2 will be. In my early impressions so far, I don’t wax into hyperbole often, but the difference in sound coming from my GoldenEar T66s has never been this good. Incredible sense of space between instruments and vocals, 3D soundstage, dynamics… it was all there. I literally got up a few times to make sure my surround speakers were not on by mistake, that is how 3D the sound was! Musical Fidelity Nu-Vista 600.2 Integrated Stereo Amplifier Specifications Power Output: 160W into 8 ohms, 300W into 4 ohms, 500W peaks into 2 ohms Frequency Response: + 0, –0.1dB, 10Hz to 30 kHz THD+N: 107dB ‘A’-weighted Input impedance: 100 k Ohms Dimensions (WxHxD): 483 x 187 x 510 mm Weight: 36 kg net / 44.3 kg boxed Product Name: Nu-Vista 600.2 Integrated Stereo Amplifier Product Type: Integrated Class A Amplifier MSRP: $9,999 Website: Musical Fidelity Nu-Vista 600.2 Company: Musical Fidelity I am excited to get into my media room and listen to music as soon as I am done with this preview! The early auditioning of the Musical Fidelity Nu-Vista 600.2 has already surprised me in regard to how well my T66s can sound. I really wasn’t expecting a vast change in the sonic soundscape, so color me surprised. My full review will be forthcoming in the next few weeks. I had never heard of Nuvistor tubes before and if you would like an interesting read on them, I provide this link: Nuvistor tubes The post Musical Fidelity Nu-Vista 600.2 Integrated Stereo Amplifier Preview appeared first on HomeTheaterHifi.com.

    McIntosh MSA5500 Streaming Integrated Amplifier Review

    I often rely on analogies to help develop my thoughts. This is a great way to take a known experience that I am relatively more familiar with to draw out the nuance of a less known experience – of course at some point all analogies fall apart and, therefore, they can only get us so far. I bring this up because I admit, when it comes to audio equipment that I enjoy listening to, I have a pretty sound understanding of my aural predilections. That was until I heard the McIntosh MSA5500 Streaming Integrated Amplifier – I now have a resolute understanding of my sonic tastes. While listening to the MSA5500, the analogy that came to mind was founded in my enthusiasm for cycling. Most of you are likely familiar with the fact that there are road bikes and mountain bikes. I posit that Mc’s first foray into creating a streaming integrated has resulted in something analogous to a mountain bike. Based on the body types trotting around AXPONA, the Venn diagram of audiophiles and cyclist has little overlap, so I’ll keep this succinct. On the farthest reaches of the road bike end of the spectrum, we have race bikes; designed to transfer power from rider to road as efficiently as possible, rider comfort – while considered – doesn’t top the list of priorities. Think, CH Precision 10 Series. Conversely, on the opposite end of the spectrum we have downhill bikes. Often incorporating suspension travel nearing 8 inches, rider comfort nears the top of the priority list hear if only to ensure rider and bike make it to the bottom of the mountain with one accord as quickly as possible. Think Dumbleland – and nobody could send that baby headlong down a mountain as well as Stevie Ray Vaughn. I’m going to let that analogy marinate for a bit while I touch on the specs and user experience with the MSA5500. Esthetically speaking let’s just say, if you lost your ability to see in 1975, even you know what this amp looks like. That is, Mc developed a design that connected with consumers decades ago and has leveraged that design to this day to remain one of the top selling brands in the industry. The MSA5500 is by no means a compact amp at roughly 18” wide, 6” high and nearly 19” deep. Coming in at 38 pounds, this Mc – like its siblings – is bound to make a statement. Okay, so this is McIntosh’s first attempt at an ‘all-in-one’ box and up until 4 weeks ago, I would have ignorantly said the only real difference between streamers is their software and how the unit displays “Now Playing” information. Two areas where McIntosh didn’t seem to devote much time when developing the MSA5500. It shares the same dot matrix LED display panel as just about every other Mc product – again if it ain’t broke, don’t fix it – and relies on Connect services from the likes of Tidal or Spotify for software. Another option here is to connect via a Roon server – this is what I opted for when listening. The Mc specific software that did exist – both as a web app and mobile device app – offered nothing more than the ability to enable Google Cast and to change the network name of the device. These two setting, along with a handful of others, were also available within the units own 2-dial settings interface. In the past, the sonic difference between entry-level streamers that I was familiar with was quite small and difficult to articulate. That was until I heard the Antipodes Kala 50 that Tom had in his listening room – that listening session was seriously revelatory. Not all streamers are created equal. All of this to say, when I noticed the absence of a high-resolution color display on this streaming amp, I was hopeful McIntosh went the route of focusing on the sonic characteristics of the streaming DAC module. In an effort to approach this more scientifically, I enlisted the help of a Wiim Pro Plus streaming DAC. I first listened with the digital out from the Wiim in an attempt to mark the characteristic of the DAC in with the Mc. Then I switched to analog out using the single ended connections offered on the Pro Plus – bypassing the MSA5500’s streaming DAC altogether. I rounded out my experiment streaming directly from the Mc. I was a bit disappointed that the differences weren’t more than subtle. Especially seeing as how the McIntosh is an $8,000 US piece of equipment. But, McIntosh is primarily an amp manufacturer so enough with the potatoes and beans let’s get to the meat. At risk of being too vulnerable, this amplifier had me tearing up and feeling a bit nostalgic. Let me set the stage. I started down my typical path of analytical listening using familiar test tracks to really draw out what this amplifier had to offer, and I wasn’t initially impressed. I was trying to contrast this feeling with the understanding that there are a great number of audiophiles who hold McIntosh in high regard and – certainly – they can’t all be wrong, so I put my nose down and dug in to figure out what I was missing. After noticing subtle distortions in otherwise clear and detailed recordings, I began to think what if distortion was the name of the game and thought of 70’s rock. I had to go back and tap the annals of my childhood and was brought back to sitting in the child car seat in the back of my parents car in the early to mid-90s. At that time, my parents listened to the oldies station in our town and on that station: a lot of 70’s rock. So, I queued up some Boston and I was immediately transported back in time. I think this was the first time since I began listening to high-end gear that this genre sounded so right. The big sound of the 70s; meters waving away; this amp rocks! Brad Delp screaming away; Tom and Sib rocking out; A truly energetic and engaging performance. After wiping my tears of anamnesis, I returned to my familiar playlist of test tracks – music with breath, openness, and minute detail – to develop a clearer understanding of what the MSA5500 has to offer. This is where I return to my analogy; the MSA5500 is like a cross-country mountain bike which has suspension with minimal travel and wider tires to absorb some of the bumps along the way. It’s certainly more forgiving than the road race bike, but not so mushy gushy that you’ll wanna send it careening down the side of a mountain. This also means that if you just want a little easy listening in the back, the MSA5500 puts on quite a detailed and balanced sonic performance – the amp sounds well composed. It’s when you give the volume knob a twist that it begins to color the music a little more, favoring energy in the bottom end. For instance, on Tu Con El from Rauw Alejandro’s 2024 album Cosa Nuestra. Alexis Perez’s snaps on her upright bass are presented with force. This bump in bass energy left for relaxed and sustainable listening even if it didn’t offer the greatest fidelity. This favoring of the bottom end tends to leave the upper octaves sounding ever so subtly dissonant. That said, I feel this may we well judged by McIntosh as often listeners find equipment that more transparent in the upper half of the frequency spectrum to be fatiguing – although I argue this doesn’t have to be the case. With 100 watts per channel into 8 ohms, dynamically rich recordings are no trouble for the MSA5500. The Audiophile Society’s recording of the Czech National Symphony performing Strauss’ Also sprach Zarathustra is just one example of this. Many of you are likely familiar with this piece and this particular recording presents Strauss’ work in all its dynamic glory. I was blown away at how effortlessly the Mc rendered this and, again, a dramatic performance from the meters. With its gently juicy sound and powerful dynamic punch, this amp is likely to impress. If you’re more of an analytical listener who wishes to queue up an aria from an 18th century opera and settle in with a glass of wine, there’s equipment on the market that will certainly please you – this isn’t it. However, if you’re more inclined to grab some beers and rock out with some buddies while going hand after hand in poker or covering each other’s back in Call of Duty, look no further than the McIntosh MSA5500 Streaming Integrated Amplifier. And don’t forget to make listing fun again! The post McIntosh MSA5500 Streaming Integrated Amplifier Review appeared first on The Absolute Sound.

    PS Audio Stellar Strata MK2 Integrated Amplifier Review

    I have known Paul McGowan, CEO of PS Audio, for many years and have reviewed a number of his products. They always deliver good value for the dollar, and the PS Audio Stellar Strata MK2 Integrated Amplifier is no exception. We (Dr. Yongki Go) reviewed the first version back in December 2020, and here, in the summer of 2024, it’s the MK2, reviewed by JJ with lots and lots of revealing bench tests. Highlights PS Audio Stellar Strata MK2 Integrated Amplifier Highlights Plenty of features, including DAC and phono preamplifier Compact Introduction PS Audio is an audio icon in the industry. Paul McGowan has helmed it for decades, although his son is now becoming more in charge. One of the first PS Audio products I obtained was a power regenerator that took the incoming 120 Volts AC, converted it to DC, and then regenerated the power by using a 60 Hz sine wave. The output was 2,000 Watts of 120 Volts, 60 Hz power with no noise. Over the years, I corresponded with him and did a video interview with him during his early years at CES in Las Vegas. Those power regenerators are now all Class D, as is the current product under review, the PS Audio Stellar Strata Integrated Amplifier. This is the MK2. We reviewed the first version several years ago. The MK2 has an MM/MC phono preamp section that the first version did not have, and the first version had a streamer capability, while the MK2 does not. Also, the DAC was completely redesigned for the MK2. PS Audio Stellar Strata MK2 Integrated Amplifier Specifications BASICS: Integrated Stereo Preamplifier and Power Amplifier POWER OUTPUT: 150 Watts per Channel into 4 Ohms POWER TYPE: Class D INPUTS: XLR and RCA Analog, Phono RCA Analog (MM and MC), Digital: USB-B, RCA, Optical, I2S, DSD OUTPUTS: RCA Preamplifier, Speakers, Headphones, Trigger, USB-A (for Software Updates) VOLUME CONTROL: 100 dB in 1 dB Steps BALANCE CONTROL: ± 14 dB in 1/4 dB Steps PHASE CONTROL: Digital Sources DIGITAL FILTERS: Three for PCM Sources INPUT TRIM: ± 10 dB for Each Input DIGITAL FILTERS: Three for PCM Sources INPUT IMPEDANCE: 47 kOhms RCA, 100 kOhms XLR MAXIMUM INPUT LEVEL: 16 Volts RMS PHONO INPUT LOADING: 47 kOhms, 100 pF for MM, 100 Ohms, 470 pF for MC PHONO INPUT GAIN: 40 dB MM, 57 dB MC FREQUENCY RESPONSE: 20 Hz – 20 kHz, ± 1 dB THD+N: 0.02%, 10 Watts, 4 Ohms HEADPHONE OUTPUT: 300 mW @ 300 Ohms, 3.25 Watts at 16 Ohms DIMENSIONS: 2.8″ H x 17″ W x 13.5″ D WEIGHT: 21 Pounds MSRP: $3,499 USD Website: https://www.psaudio.com/ Company: PS Audio SECRETS Tags: PS Audio, Stellar, Strata, MK2, Integrated, Amplifier Secrets Sponsor Design The PS Audio Stellar Strata is a medium power (100 Watts per channel into 8 Ohms) integrated design that includes a DAC, capable of 24/384 sampling, DSD 256, and an MM/MC phono preamplifier section. The power amplifier is Class D. This means high efficiency, but also, it is compact enough that it really looks nice (hint: spouse approved). It only gets warm during use, never hot, so ventilation is easy. The rear panel has a plethora of inputs and outputs. Click on the image below to see a full-sized version. There is one set of RCA and XLR analog inputs, MM and MC analog phono inputs, analog RCA preamplifier outputs, and a full set of digital inputs including RCA, HDMI, USB, and Optical. The two sets of speaker binding posts are heavy-duty. There is a separate USB-A input on the left side for software updates. The 120 Volt AC input socket is grounded, and there is a toggle on/off switch. The front panel has another on/off (standby) button on the left side. On the right end of the front panel is a 1/4″ stereo phone jack to plug in your set of headphones, using the built-in headphone amplifier (3.25 Watts into 16 Ohms). The remote is small, with buttons for power, volume, phase, dim, mute, and input selection. HT is for the HDMI inputs. Volume control is by the unlabeled horizontal button in the middle, but you can also adjust the volume using the up and down arrows. I took this photo on my dinner table placemat. I had to find a space that didn’t have spaghetti sauce stains. In Use I used the PS Audio Stellar Strata Integrated Amplifier with an HP Laptop USB-A digital output to the digital USB-B input on an AURALiC ALTAIR G1 Digital Audio Streamer and a VPI HRX turntable with Sumiko Blackbird MC cartridge. Speakers included Aperion Verus III Concert V8B and Polk Audio R200AE (both of these models are stand-mount speakers). The cables were by Clarus. Here are my standard test albums. I don’t use them all with every review, but I do use some of them. Art Pepper, “Art Pepper meets the Rhythm Section” First, my favorite album for tests, is Art Pepper’s classic, Art Pepper meets the Rhythm Section. It is fantastic in either digital or vinyl versions. I have both, and they sounded great either way. I also used this album to test the headphone amplifier in the Strata. I had a set of HIFIMAN HE-400 over-the-ear headphones on hand. When headphones are plugged in, the speaker outputs are muted. There was plenty of volume, and the sound was clear. Anne Akiko Meyers, “Mirror in Mirror” This album, Mirror in Mirror, Anne Akiko Meyers (Violinist) is a very important one to me in my listening tests because she hits the highest violin notes I have ever heard in a recording, and the high frequencies are more difficult for amplifiers than low frequencies. They sound a bit bright with the Strata but not objectionably bright. Actually, they are stimulating. The bench tests indicate some increasing distortion at such high frequencies. Uranienborg Vokalensemble, Elisabeth Holte, Inger-Lise Ulsrud, “Himmelrand” Himmelrand is a beautiful album with powerful deep organ notes. It is also a very full-bodied sound since many organ keys are being played at the same time. I was surprised at how well the PS Audio Stellar Strata handled them. Really deep and intense. Louis Lane, Atlanta Symphony Orchestra, “Copland: Appalachian Spring Rodeo, Fanfare for the Common Man” Another good test album, and my favorite recording of this composition: Copland’s Fanfare for the Common Man, Telarc. It has very powerful bass drum thuds throughout the recording. The Stellar Strata handled them perfectly. The London Oratory Schola Cantorum, Charles Cole, “Sacred Treasures of Venice” Sacred Treasures of Venice, Hyperion, 2024 is a 24/96 recording. I am glad to see that new releases these days are more commonly in high-resolution sampling. It has taken a surprisingly long time to get here. Anyway, this is an album of religious choir music. All the various voice levels, basso, tenor, alto, etc. were separable from one another when they were all singing together. In other words, no congestion. I was in Venice in the Spring of this year. The pizza was great! Tony Bennett & Diana Krall, “Love Is Here to Stay” I listen to a lot of Tony Bennett and Diana Krall, and some of my standard albums are their music. This one has them together, Love is Here to Stay. Very smooth and easy to listen to. Secrets Sponsor On The Bench It was a pleasant surprise to see that, at low output (2 Watts), into 8 Ohms, distortion was primarily 2nd-ordered (Figure 2 below). So, at background levels, you will get a very musical, warm sound. This test was with a 1 Volt input, Volume set to 48 (max is 100), and an output of 4 Volts. Unless otherwise specified, I used the XLR analog stereo inputs on the Strata. With the same settings, but with a 4 Ohm load, the results were about the same (Figure 2). With the same input, but the volume adjusted to 78, the output was now 20 Volts. Into 8 Ohms, THD+N was 0.037%. The 2nd-ordered harmonic was about the same height as the 3rd-ordered harmonic, which is good. Same settings in Figure 4 as in Figure 3 except it was into 4 Ohms. The output voltage dropped a bit, and THD+N was almost twice as much as with an 8 Ohm load. And, now the 2nd-ordered harmonic is substantially lower than the 3rd-ordered harmonic. Moving on to the use of 19 kHz and 20 kHz sine waves, this first spectrum (Figure 5) is 1 Volt input and 3.1 Volts output into 8 Ohms, Volume set to 48. There are four distinguishable side peaks on either side of the fundamentals. And, with the same settings into 4 Ohms, Figure 6 below, the output was reduced to 2.5 Volts. There are still only five visible side peaks though. Increasing the volume setting to 78 resulted in 15.6 Volts output into 8 Ohms. There are now nine visible side peaks. This is what happens with all amplifiers. The question is how many side peaks and how high are they? The results here are about medium for a power amplifier. At 4 Ohms (Figure 8), the voltage dropped even more, to 12.85 Volts. However, the number of side peaks did not increase, although their height is a bit more. I am pleased and surprised at this result with such a reasonably priced amplifier. A standard IMD test uses 60 Hz and 7 kHz sine waves. Here (Figure 9), we used 1 Volt which produced 3.34 Volts out into 8 Ohms. IMD was 0.045%. Changing the load to 4 Ohms (Figure 10) reduced the output voltage a bit and increased the IMD. This is expected. Figure 11, below, shows the IMD at higher voltage into 8 Ohms. IMD was 0.07% which is not bad. With a 4 Ohm load, distortion was still quite manageable at 0.052%. The Frequency Response into 8 Ohms is shown below in Figure 13. The response is within 1.5 dB, 20 Hz – 20 kHz with a rise in response above 20 kHz to a maximum at 60 kHz, then a decline due to the low-pass filter that is necessary with Class D amplification. The response into 4 Ohms (Figure 14) shows a decline in response at 20 kHz rather than an increase that was shown in Figure 13 at 8 Ohms. This is typical of Class D. The sharp decline above 60 kHz is the low-pass filter. The peak at 70 kHz is the low-pass filter resonance frequency. For THD+N vs. Frequency, first the spectrum for low voltage into an 8 Ohm load. You can see a rise in distortion above 4 kHz maxing out at 0.3% at 20 kHz. Low voltage into a 4 Ohm load produced about the same results, Figure 16. Higher voltage (20 Volts) into an 8 Ohm load (Figure 17) shows more distortion in the high frequencies. And, with a 4 Ohm load, distortion is also high in upper frequencies. The spikes are caused by the Audio Precision occasionally not being quite able to handle Class D switching. Class D amplifiers have to use a low-pass filter at the amplifier’s output before the speaker to reduce the amount of the switching frequency noise to be passed. The switching frequency of the PS Audio Stellar Strata Integrated Amplifier is 100 kHz. A generic low-pass filter schematic looks like this (Figure below). The output from the power amplifier is on the left, and the RL on the right is the speaker. The problem with putting the low-pass crossover frequency too close to 20 kHz is that the roll-off will include significant amounts of energy below 20 kHz since a crossover results in roll-off below the crossover frequency as well as above it. Putting the low-pass frequency out beyond 20 kHz allows harmonic distortion in the 20 kHz to 40 kHz region to pass through to the speakers. If the filter is not strong enough, then a significant amount of the switching frequency will enter the speakers and be emitted as RF interference. On top of all this is the fact that the inductors in the low-pass filter will act as antennae and pick up the 60 Hz power supply frequency if they are not orientated properly. Even though Class D is an analog process and not digital, the switching signal does still plots sample voltages along the waveform, so the mathematical deconstruction of the waveform still produces harmonic distortion. For a switching frequency of 100 kHz, there are five voltages plotted for a complete waveform at 20 kHz. It’s all a tradeoff, but Class D is definitely in the future of audio in a big way. Power supply decoupling and audio signal filtering for the Class-D audio power amplifier THD+N vs. Power (Watts) output into 8 Ohms is shown below in Figure 19. The knee is at 75 Watts, and clipping (1% THD+N) is at 105 Watts (per channel). With a 4 Ohm load, the knee is at 135 Watts, and clipping is at 180 Watts. Testing the preamplifier by itself and using the RCA digital input jack, the results of activating the three available digital filters on the frequency response with 16/44.1 sampling are shown below in Figure 21. The digital input was 0 dBFS which means full DAC analog output into the preamplifier section, The Volume was set to 48. Each filter delivers a different roll-off response at 20 kHz. You just need to try them all to see which one you prefer. Filter 2 gives the most high-frequency roll-off, and this will make the sound a bit smoother. Since this Class D amplifier has quite a bit of high frequency distortion, start with Filter 2, and then switch to the others, using music that has a lot of high frequencies, such as violins. Figure 22 below shows a 19 kHz, and 20 kHz test with the RCA digital input, 16/44.1 sampling, and the DAC set to minus 5 dBFS. Volume was set to 48. Output was 176 mV. There are only 2 side peaks (2 on either side of the 19 and 20 kHz fundamentals), indicating the DAC and analog preamplifier section are quite good. Figure 23 below shows a 1/10th decade response of the preamplifier, using the XLR analog inputs, preamplifier outputs, 1 Volt input, and volume set to 48. Distortion is relatively low. and it is spread evenly throughout the audible spectrum. And, finally, the phono preamplifier. There are two sets of phono preamp RCA input jacks on the rear panel, one set for MM (Moving Magnet) cartridge inputs, and a second set for MC (Moving Coil) cartridge inputs. Using whichever set you need, connect your turntable cartridge outputs to the appropriate set, then, pressing the menu button to the left side of the front panel display, you hold it down until the menu items appear, then click the button several times until you reach “Audio”. At that point, you have about 1 second to click the menu button twice, which brings up a set of sub-menu items. Click the menu button until you see MC or MM, whichever one happens to be currently selected. Then turn the volume control until you get the one you want, either MM or MC. Then press the Input 3 button on the remote control, which will take you back to the main display, showing “Phono” as the input. Turn the volume control down put on an LP, and adjust the volume up as needed. Shown below in Figure 24 are the frequency responses for MM and MC inputs. MM has less gain because MM cartridges generally have higher output than MC cartridges. The volume control setting will also be different. You can see that the MC input has less gain in the lower frequencies than the MM input. The Number of FFTs Affects the Shape of the Sine Wave Spectral Peaks A bit about the shape of the sine wave spectral peaks. When a test signal is analyzed, an FFT (Fast Fourier Transform) is used. This is a digital mathematical procedure that deconstructs the analog waveform into its fundamental frequency(ies) and harmonics, whether the harmonics are from musical instruments or harmonic distortion peaks. In the figure below, connecting the output of a laboratory-grade soundcard to its input, a 1 kHz sine wave spectrum is shown, resulting from a 128 FFT analysis. Note that the base of the peak is wider than the top of the peak. This is an FFT artifact due to FFT analysis limitations. We can increase the number of FFTs to 256 as shown below. Note that the base of the 1 kHz peak is narrower than with the 128 FFT analysis. Let’s go to 512 FFTs. The base is even more narrow. And, now, 1 Million FFTs. The base of the 1 kHz peak is really narrow. One can go on and on, even out to 4 million FFTs. It all depends on what you want to show. The problem with a high number of FFTs is that it takes a lot longer for the analysis to finish. Also, the FFT size alters the resolution of the resulting spectra. The number of spectral lines is half of the FFT size, and the frequency resolution of each spectral line is equal to the sampling rate divided by the FFT size. I use either 256 or 512 FFTs in my analyses. But, what I wanted to show here is that the wide base of a spectrum peak is not a Device Under Test (DUT) problem. It is just an artifact in the mathematical process of analyzing an audio signal. It can be broadened by noise that modulates (IM) the frequency peak, but it is still an artifact because the modulation peaks are not individually resolved. Conclusions For $3,499, the PS Audio Stellar Strata Integrated Amplifier is a very nice package. The Class D power amplifier has its advantages and disadvantages, but it will get the job done. The whole thing is very compact, and as such, looks great on a hi-fi stand. Its power amplifier doesn’t have the watts to blow the walls out, but that is not its purpose. Women have good equipment too. Likes Good-looking component Solid construction Lots of features Excellent value Would Like To See All menu and submenu items accessible from remote control The post PS Audio Stellar Strata MK2 Integrated Amplifier Review appeared first on HomeTheaterHifi.com.

    Ollech & Wajs 8001 Hands-On Review

    Ollech & Wajs 8001 Integrated sports watches have been all the rage and OW pulled from their archives to create this Ollech & Wajs 8001. The 8001 is inspired by the OW Reference 8000 below and is updated for 2023. Well, I shouldn’t say updated as clearly, these are different watches. Still, they took that retro TV cushion chronograph design, and modernized It to a 3-hander date model, with a lot of water resistance, the familiar OW look that they have been doing the past few years, a massive crown, a Havana fume dial, and well a bracelet that is not going to fit everybody. OW Reference 8000 Specifications: 39.5mm by 39.5mm stainless steel case 12.7mm thick 55mm “lug to lug” 187 Grams Soprod Newton P092 COSC Movement 300m Water resistant Sapphire Crystal Screw Down case back and crown Quick Extension bracelet Price $2,034 https://ow-watch.ch/collections/ollech-wajs-watches/products/ow-8001 Let’s start with the overall look of the Ollech & Wajs 8001. I think this is a pretty cool and funky-looking piece and the big part of the appeal for me is the blocky case, with the all-squared-off design, and all-brushed finishing. This is not a standard design at all, and it was one of the things that initially drew me to this watch when I saw it last year. From a visual aspect, this watch stands out! The design is definitely out there from the side view especially, and from the top down it still has a distinctive look, but when wearing it on the wrist, that’s a bit of a different story. And I am not going to make you wait to get to the real issue with this watch. I will discuss the dial and movement and everything else down below, but let’s not keep you in suspense. There is a big problem with this watch and it’s that not everyone is going to be able to wear it, and that is simply because of how this is integrated and lug construction. Now I really get into this in the video, but to condense it a little bit, basically, the lugs are made by the bracelet itself and they attach to a solid male link coming off that blocky case. Those “end links” also smack right up against the case, meaning there is no articulation whatsoever for the lugs. And the lugs point outwards, not down, so effectively this makes the lug to lug 55mm, on a watch that is only 39.5mm wide. As you can see in the above photo, that is going to make it interesting to wear for people with wrists smaller than, you know what, scratch that, it’s going to make it interesting for people with wrists, period. Yeah pretty much this is going to wear long and a little odd on pretty much anybody’s wrist and I think anyone considering this watch needs to be aware of it. The lugs do not curve at all, and in the above photo you can see how the top lugs are kind of kinked and there is a big gap underneath. That’s just how this watch wears. It looks like a bangle, a big, blocky bangle that tells time. My wrist is 7.5 inches (19.05cm) and 55mm is the absolute limit for my flat wrist, and while it does technically fit, the lack of articulation in the lugs is just weird. If the lugs were able to swing and move down, or the case curved down, this would wear very differently, and even though it’s not uncomfortable, it is just a bit odd. The bracelet of the Ollech & Wajs is a chunky oyster-style bracelet with screws and a rachet quick extension clasp, although this is the older style, long clasp, not the newer sleeker ones, with this watch design, this blocky clasp works here. So you can size it easily and have a clasp that will allow you to get an even better fit, but it won’t do anything for how the lugs wear on your wrist. Unsized, this watch weighs around 187 grams, so it’s not exactly lightweight either. Okay, so I’ve covered how it wears, but what about the rest? Well, like I said, this design, I do love it. The dial of the Ollech & Wajs 8001 is a fume dial, a Havana fume dial to be exact, which means it has a brownish tinge to it, that can look grey in certain lighting and that gets lighter towards the center of the dial, which doesn’t work on every way but suits this piece just fine. And while there may be a few lines of text and a logo and the brand name on the dial, it doesn’t feel cluttered or overdone, mostly due to the fact the text and logo are all printed in white and seem to kind of just blend in. And of course, the date is located at the 6 o’clock position, my favorite place for a date and it keeps it all symmetrical. Weirdly though, only 3 indies are applied indices, the rest are painted on the dial, something OW has done with a few other watches in their lineup, and those are the only indices that are lumed as well. More on that in a bit. The overall dial layout is very similar to the OW 350CI, though the hour, minute, and second hand are right off the M-110 I reviewed a few months ago, with the hands and indices having that rough brushed finish, a finish that complements the brutalist design language of this watch. The bezel is fixed, even though it has numbers and markers on it, and the large, almost 8mm crown adds to the style of this watch while also being very functional and easy to grasp and operate. The crown does screw down as does the case back and oddly enough this non-dive watch is rated to 300m of water resistance. This means you can pretty much take this to the ocean, to the lake, in that YMCA pool, or Niagra Falls and it should hold up well, but 300m is probably a little overkill for a watch that is not a dive watch. Still, it does make this kind of a GADA type of watch, though I am not sure this one would look good with a tux. People where Apple watches with tuxes these days, so what do I know? Powering the Ollech & Wajs 8001 is the Soprod Newton P092 movement, a movement OW worked closely with Sorpod with, and this time it is COSC. OW used this movement in the OW M-110 and as I said with that model, I found no issues with it, winding and using the crown are very smooth, with the power reserve as stated. I know initial reports of this movement (not this modified OW one) stated it had crown issues and floaty hands, but I have experienced none of that in two different models. I will state my time before a review is usually limited to a few weeks, but I have not seen reports of issues with the OW models that have these movements. And like I said, this one is COSC and has been keeping time at 2 seconds fast per day. As I mentioned earlier in this review, only 3 of the indices are lumed, along with the hour, minute, and secondhand arrow. Unfortuanly this is not the first watch from OW that I have experienced this with, and while the light blue (C1?) SuperlumiNova does glow well on the areas it is applied, I wish they had just lumed all of the indices. I was excited to get this watch in hand for review. Like really excited. I loved the look of it from the moment I saw it, and when the watch was on the way to me, I looked up a few reviews and saw the issue about the lugs and lack of articulation. Still, I thought, it can’t wear that bad, and it isn’t that long right? Well, I do not think it wears as bad as some claimed, and it’s not 60mm in overall length like some claimed either, but yes, this watch does not wear like I thought it was going to, or I guess I should say like I wished it would. The look is still very attractive to me, and even at 39.5mm wide, which is generally smaller than I like, the watch head does not feel small to me, probably because of the blocky case and that large crown. I can wear this watch, and it’s quite the statement piece, but it’s not a watch I would probably wear often and while not uncomfortable, I am very aware of this big block of steel on my wrist while wearing it. At just a little over $2000, the Ollech & Wajs 8001 does have a lot to offer with the COSC movement, a unique and retro design, a beautiful dial, and very good build quality, but I think many will be put off by how this wears. I will say it doesn’t seem like OW is shying away from how it wears though, as even on their website there is a pic of a model with it on, and it is jetting off his wrist as well, more so than it does on mine. It seems this design and implementation of the lugs was clearly on purpose and this is the look they were going for. Still, I would have loved this watch so much more if the bracelet lugs were able to swing freely from the male end link and drop downwards. It would change the entire feel of the watch. Maybe one day Ollech and Wajs will make a 2.0 version. Until then, visit the OW website if this watch interests you or if you want to check out the rest of their lineup. The post Ollech & Wajs 8001 Hands-On Review appeared first on WatchReport.com.

    Integration Tests in .NET WebApi

    In software development, testing is an essential aspect that ensures the stability and reliability of applications. Three primary types of tests are commonly used: unit tests, integration tests, and end-to-end tests. In this blog post, we will discuss these testing types in the context of a .NET WebAPI project and provide an example implementation of integration testing using an in-memory database. Unit Tests, Integration Tests, and End-to-End Tests: What’s the Difference? Unit tests focus on testing individual units or components of your application in isolation. This type of test verifies whether the unit/component works correctly and adheres to its business logic. Integration tests aim to test multiple units or components together, ensuring that they interact properly. Integration tests can uncover issues related to data flow, communication between components, and external dependencies like databases. End-to-end (E2E) tests simulate a complete user scenario by testing the entire application from start to finish. E2E tests can help identify issues related to multiple components, external APIs, and user interfaces. Example Implementation in .NET To perform integration tests, we will use an in-memory database and the WebApplicationFactory feature of ASP.NET Core. This approach allows us to test our WebAPI application with a real web server in memory, simulating how the components interact with each other when making requests. First, let’s create an InMemoryDbAppFactory that sets up our in-memory web server and database: public class InMemoryDbAppFactory : WebApplicationFactory { private readonly string _environment; public InMemoryDbAppFactory() { _environment = "IntegrationTests"; } protected override void ConfigureWebHost(IWebHostBuilder builder) { Environment.SetEnvironmentVariable("ASPNETCORE_ENVIRONMENT", _environment); builder.UseEnvironment(_environment); builder.UseSetting("https_port", "8080"); builder.ConfigureTestServices(services => { services.RemoveAll(); services.TryAddTransient(); // Anonymous authentication services .AddAuthentication("Test") .AddScheme("Test", options => { }); }); } } In order to use an in-memory database, we will override the connection string injection in our ServiceCollectionExtensions: public static partial class ServiceCollectionExtensions { public static IServiceCollection AddDbContexts( this IServiceCollection services, IConfiguration configuration, IWebHostEnvironment environment ) { if (environment.IsEnvironment("IntegrationTests")) { var connDb = new SqliteConnection("DataSource=db;mode=memory;cache=shared"); connDb.Open(); services.AddDbContext(options => options.UseSqlite(connDb)); } else { services.AddDbContext( options => options.UseSqlServer(configuration.GetConnectionString("ConnectionString")).UseExceptionProcessor(), ServiceLifetime.Scoped ); } return services; } } Finally, this is how a test looks like: [Collection("MemoryDbIntegrationTests")] public class ApiTests : IClassFixture { private readonly InMemoryDbAppFactory _factory; private readonly HttpClient _client; public ApiTests(InMemoryDbAppFactory factory) { _factory = factory; _client = factory.CreateClient(); // Ensures a clean database before each test factory.ResetDb(); } [Fact] public async Task GetList_Should_Return_List() { // Arrange // Act var response = await _client.GetAsync("/api/list"); var content = await response.Content.ReadFromJsonAsync(); // Assert response.EnsureSuccessStatusCode(); // Status Code 200-299 content.Should().NotBeNull(); content.Should().HaveCount(2); } } Using an in-memory database for integration tests has both advantages and disadvantages: Advantages: Faster test execution: In-memory databases provide quicker test execution times since the data is stored in memory instead of on disk. This can significantly improve your overall testing performance and help you find issues faster. Easy to set up and tear down: In-memory databases are easy to create, modify, and delete without the need for external dependencies or configuration changes. This makes it easier to write, run, and maintain your tests. Consistent test data: In-memory databases allow you to create a known set of data for your tests, ensuring that each test starts with the same initial conditions. This can help reduce the likelihood of inconsistent test results and make it easier to identify issues related to data flow or dependencies between tests. Disadvantages: Limited scalability: In-memory databases have limited capacity and may not be suitable for testing large datasets or complex scenarios that require high levels of concurrency. Lack of realism: In-memory databases may not accurately represent the behavior or performance of a production database, especially when dealing with complex queries or data modification operations. This can make it difficult to identify issues related to database schema, indexing, and query optimization. Limited support for advanced features: using SQLite as our in memory database we don’t have support for multiple schemas and some advanced query features. Seed data: the need to create seed data can be tedious and time consuming. When deciding whether to use an in-memory database, mock data, or a real web server in memory for your integration tests, consider the specific requirements of your project and weigh the advantages and disadvantages of each approach. In many cases, using a combination of testing types and approaches can help you ensure the stability, reliability, and performance of your .NET WebAPI application. The post Integration Tests in .NET WebApi appeared first on Blog IT.

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