Audiophilepure

https://www.hifichoice.com/content/audio-research-reference-80s

Impressive though Audio Research’s Reference 80S undoubtedly is, there’s a sizeable elephant in the room that should perhaps be put to one side before we go any further. With a £15k price tag, this absolutely isn’t typical HFC fare, which almost immediately puts it out reach of most wallets. Which is a real shame as this is a quite stunning power amplifier that does the easy bit of delivering the power, while handling the more challenging side of subtlety and fine detail with absolute aplomb. In the highly unlikely event that you inadvertently stumble across that lost winning lottery ticket or a rich relative that you never knew about leaves you stacks of cash only on the understanding that you spend them on hi-fi exotica, this is an absolute must-have. For the rest of us it’ll have to remain a dream to aim towards. Regardless, there’s no disputing that the way the Reference 80S delivers the sort of precision that’s more commonly the realm of solid-state rivals from glass tubes is nothing short of miraculous. 

https://audiophilestyle.com/ca/reviews/aurender-ap20-integrated-review-r1256

he design of the AP20 is really something to behold. It’s the right horse for not just a single course, but many courses. Its flexibility enables it to be used as an all-in-one or as a single component of a larger system, or as something that falls in between those two. I used it in two different systems, and mainly as the only component connected to my Wilson Audio Alexia V loudspeakers. I still have a smile on my face when thinking about playing Mahler’s Third through this system, with little volume attenuation. Enough transients to scare any listener and plenty of delicacy to please even the most discerning audiophile. The team at Aurender has seriously outdone itself.

https://www.stereophile.com/content/emm-labs-mtrs-power-amplifier

The EMM Labs MTRS is the finest, most musically complete stereo amp I’ve reviewed to date. As much as the word “neutrality” come to mind, it falls short as a descriptor of sound as honest, true, thrilling, heart-warming, and emotionally rewarding as the MTRS’s.

The MTRS is a must-audition for any music lover with the space and budget to give it a home. Hey, even if you don’t have the bucks to buy one, give it a listen. If you don’t, you’ll miss out on experiencing the significance of Ed Meitner’s accomplishment and the greatness of his team’s achievement.

https://www.hifichoice.com/content/audio-research-reference-80s

Impressive though Audio Research’s Reference 80S undoubtedly is, there’s a sizeable elephant in the room that should perhaps be put to one side before we go any further. With a £15k price tag, this absolutely isn’t typical HFC fare, which almost immediately puts it out reach of most wallets. Which is a real shame as this is a quite stunning power amplifier that does the easy bit of delivering the power, while handling the more challenging side of subtlety and fine detail with absolute aplomb. In the highly unlikely event that you inadvertently stumble across that lost winning lottery ticket or a rich relative that you never knew about leaves you stacks of cash only on the understanding that you spend them on hi-fi exotica, this is an absolute must-have. For the rest of us it’ll have to remain a dream to aim towards. Regardless, there’s no disputing that the way the Reference 80S delivers the sort of precision that’s more commonly the realm of solid-state rivals from glass tubes is nothing short of miraculous. 

The reason a low output impedance is important is that, with the input impedance of a speaker being about 4-8 Ohms, the amplifier’s output impedance forms a voltage divider such that there is a voltage drop across the speakers. The ideal output impedance would be zero Ohms. Since this is not possible, what we would hope for is 1/100th output impedance compared to the input impedance of the device connected to the output. This is easy when connecting the output of a preamplifier to the 10 kOhms – 100 kOhms input impedance of a power amplifier. But for a power amplifier connected to a pair of speakers with 4-8 Ohms impedance, this is much more difficult. The output impedance of a solid-state power amplifier is usually less than 1 Ohm, but for a tube power amplifier, it is usually between 1 and 5 Ohms even with the output transformer. So, at least a small amount of voltage drop is inevitable with the tube amplifier. The V 110 SE has an output impedance of 2 Ohms.

https://www.soundandvision.com/content/arcam-a25-and-st5-stereo-system-review

When connected digitally, there is just a single volume control displayed on the A25; when using the analog connection from the ST5, each device has independent volume controls. As such, it was possible to overload the inputs to the A25 by maxing out the volume from the ST5 while the volume on the A25 was low. The slight distortion vanishes after balancing the gain between these units, and using the TOSLINK or digital coax connection completely eliminates it. I found no reason to use the analog connection, especially considering the ST5 uses a high-quality ESS ES9018K2M high-resolution DAC. This same DAC is used in the A25.

I prefer to stream Tidal, especially for sound quality evaluations. I queued up Norah Jones’ latest release, “Staring at the Wall”, a delightful collaboration with Leon Michels. The ST5 and A25 captured every nuance of this upbeat and insanely catchy song. Jones’s tripled vocals with lead and harmony were distinct, and even the slightly detuned piano was conveyed transparently. The overall mix has a raw, garage-studio quality, and all of the imperfections of the performance are captured.