Audiophilepure

https://www.theaudiobeat.com/equipment/convergent_audio_technology_jl5_limited_edition.htm

After 25 years, I’ve still not discovered a single amp that’s everything to everybody, if such a beast even exists. But I’ve now heard one that comes closer than any other. The CAT JL5 Limited Edition brings together tremendous drive with transparency and, for lack of a better term, humanness. It has the body and presence that bring performers to life, the power reserves to keep up with seemingly any music played at any level, and the clarity to reveal the qualities of each recording. And the JL5 has its own set of super powers, which include exceptional control, wide dynamic range and high resolution, all while driving any speakers (or a pair of huge passive subwoofers). It also displays the tonal beauty of great tubes, in a package that costs less — even far less — than other stalwarts.

Ken Stevens is a unique audio character and as confident as a shaman in his message: that everything that goes into creating audio electronics matters to the sound, that tubes don’t have to give to and take away from the music, that an all-triode amp doesn’t have to peter out when the music gets really loud or really dynamic, and that a stereo amp that achieves all of this doesn’t have to cost six figures. How the JL5 is a Limited Edition is a mystery, because I’m sure CAT will make as many as the company can sell, but it is an audio rarity, and a musical revelation too.

https://www.stereophile.com/content/dan-dagostino-master-audio-systems-progression-m550-monoblock-power-amplifier

Following late-night phone consultations with Editor Jim Austin, I awoke to speak with Bill and Dan about the possibility of delaying the review and sending the amps back to Arizona for repair. Dan, though, was certain that the amps were fundamentally sound. He thought the discrepancy was caused by a shift in biasing, which presumably happened during shipment.

Two tension-fraught days later, Hans Brackmann, Definitive Audio’s store manager, drove to Port Townsend to rebias the amps. All D’Agostino dealers are prepared to rebias the M550s whenever necessary.

Sure enough, rebiasing was called for—just that, nothing more. By the time Hans left, both channels sounded the same (save for minor discrepancies caused by room imbalances), and I heard even more of the beautiful, smooth, finely detailed, impeccably controlled, remarkably dynamic, slightly warm and glowing sound that had made me fall in love with the Progression M550s.

My listening room was designed from the start to provide a fairly close approximation of the Cardas Golden ratio, and was wired with dedicated outlets for the audio stack. I’ve since upgraded the setup with AudioQuest Edison NRG power outlets, and with the other AudioQuest Niagara equipment that I’ve been able to add, I’ve achieved an incredible level of quietness within my room and system. So I can easily discern any electronic hum or buzz coming from any particular piece of equipment within the room. A very slight hum emanated from each piece of the Wells Audio equipment that was clearly audible when standing near them, but was much less obvious from my listening position, which is about 18 feet from the equipment stack. During operation, no noticeable noise was present in the audio spectrum with either analog or digital sources. 

I run the LRS loudspeakers full range with a pair of subwoofers, a REL T1 and a Definitive Technologies Powerfield 1500, with no crossover employed between the loudspeakers and subs. Over the two years the LRS has been in my system, I’ve gotten the sub placement and levels dialed in to the point that playback is absolutely seamless with any musical genre. The LRS has the uncanny ability to produce shockingly loud SPLs with music that pushes levels that approach total realism for orchestral and even rock music. Which is completely surprising, especially for such a seemingly fragile technology that employs aluminum foil that’s glued to a mylar substrate. I’m pretty convinced that providing a great, high current amplified signal to the LRS is the key to getting perfect musical performance.

https://www.hifinews.com/content/bat-vk-3500-integrated-amplifier

The more time I spent with the VK-3500, the more strings I found to its bow. When fed some modern, techy electronica (and even with a regular-sized standmount), the impression is that it wouldn’t be out of place doing front-end duty in a nightclub. Paul Oakenfold’s ‘Save The Last Trance For Me’ [A Lively Mind; Perfecto PERCD003] came straight out the gate at full-throttle, a pounding drum track underneath waves of reverberant synths. Yet this slab of euphoria was peppered with surprisingly delicate touches, such as an isolated high-pitch woodblock that echoed serenely right

And with a track where bass is less prominent, the VK-3500 is able to shift gear easily. Through the big Paradigm Founder 100F loudspeakers, the sustained organ notes, soft strings and falsetto vocals of ‘Pause’, by multi-instrumental outfit Emily Barker & The Red Clay Halo [Almanac; Everyone Sang; 88.2kHz/24-bit], were painted in varying subtle shades. The recording was utterly spine-tingling.

Even though the Shinai offers a nice dose of bloom and gentle warmth, importantly, there’s absolutely no excess of warmth and also no “saddle” effect, in which the midrange is structurally dialed back compared to the bass and treble. Principally, the amp just sounds linear, and it adapts to the music. When playing Toni Braxton or Anita Baker, the Shinai delivers the music with what seems like a subtle golden glow but as soon as you play something spicy like Robert Palmer’s You Are In My System, or basically, anything produced by Michael Frank, the amp immediately flexes its muscles, throws out any idea of sugar-coating and slaps me right in the face with its immediate dynamics! It may sound as if I am being overly dramatic, but really, I am not exaggerating. Whenever I play something spicy, it comes out as such, totally unrestrained.

It’s the seemingly impossible: a very neutral and linear amplifier that is fast, expressive, and dynamic but equally lush, liquid, and seductive, but this is exactly what the Shinai + Combo Stand achieves.

This bass response was partially due to the KT120, but was primarily due to the fixed bias nature of the amplifier. In tube amp design there is a debate over whether fixed bias designs or cathode bias designs are better. Fixed bias will almost always produce better bass, but it may make the amp less dynamic and airy. The Bryce Monos though had it all, great bass and airy and extended highs. Whether it was Alanis Morissette or Mika, trumpets or cymbals, these amps simply delivered in extensions and airiness.

Like ampsandsound’s other single-ended amps the Bryce Monos have a reference midrange. Voices appear to float in the center of my listening room. It draws you in with a texture that makes you want to reach out and touch the invisible person singing in the center of your room. Closing your eyes, you can begin to make out the movements of the singers jaw. This is not an overload of detail, but simply the Bryce’s ability to render an incredibly high resolution experience. This is particularly apparent on The Mountain Goats, Jordan Lake Sessions album. As John Darnielle belts out the word to “This Year” you can feel the emotional toll the year has taken on him, as well as the rest of the band. You can also very clearly hear the room he is in. The saxophone remains locked in place, swinging on the stage in a disturbing but shockingly realistic way. I realized I was literally hearing the saxophonist rock back and forth to the beat.

https://www.stereophile.com/content/audio-research-vt100-power-amplifier

Timbral Coherence: With the VT100 it became irrelevant to speak about how the amplifier recreated the bass, the midrange, the highs. The amplifier did not break down a musical event into its component tonal parts. Given a good recording, the VT100 recreated the timbral architecture of the voice or instrument as a single, coherent musical event.

Given a very good recording, the VT100 caused me to throw my notebook away. I recently acquired a bunch of Classic Records jazz reissues and, using the VT100, set out to undertake a comparison of the LPs with my originals. With each recording, I lost sight of my mission. By the end of the listening sessions, I realized I’d never even bothered to dig out the originals. The Classic reissues sounded so lifelike I didn’t care what the originals sounded like.