Audiophilepure

https://www.stereophile.com/content/fern-roby-amp-no-2-integrated-amplifier

One night, as I was listening to my system with the Amp No. 2, I found myself thinking, Omg! This amp is really lighting up those DeVores! I wondered how F&R managed to get this much vivid, high-energy excitement out of an amp that looks laid-back and tasteful. Then I remembered that the Amp No. 2’s designer, Michael Bettinger, and his company G.A.S. have carried on a 40-year relationship with the designs of one of my heroes, James Bongiorno, chief designer at SAE, G.A.S., and Sumo.

As I remember it, Bongiorno’s wild-style Ampzilla was the opposite of tasteful and domestic. It had an industrial look and a type-A personality, and it was the first solid state amp I felt I could marry and settle down with. During these auditions, Fern & Roby’s Amp No. 2 performed like a silk-suited version of that renowned monster. And that is extremely high praise.

https://www.stereophile.com/content/linn-klimax-solo- Review800-monoblock-power-amplifier

The amp’s support feet, derived from those on Linn’s flagship Klimax DSM network music player, are machined stainless steel with an impressed silicone O-ring to aid isolation. Their height ensures that Linn’s natural convection cooling process functions as intended. Nonetheless, Rodger gave me the okay to try aftermarket feet, noting that during the design process, Linn listened with its own feet and “very standard interconnects and speaker cable.”

More on this topic follows. Linn doesn’t think the Klimax Solo 800’s Utopik power supply requires external power conditioning, and Rodger doesn’t think the monoblock will feed back noise into the line. “That said, if an end user wants to employ a high-end [power] conditioner, and they like what it does to the sound of the whole system, we have a saying in Scotland: ‘Fill your boots,’ which means ‘that’s your prerogative, so go for it.'”

Upon receiving the Linns, I was advised to leave them on 24/7. Standby kicks in after 20 minutes of silence; when it happens, what Rodger called “a jaunty little animation” appears on the tastefully illumined LED roundel in the center of the front panel.

https://www.hifinews.com/content/hifi-rose-ra280-integrated-amplifier

There’s no power or agility lacking here, so the RA280 typically communicates dynamics and excitement without edging into extreme warmth or betraying an undue focus on high treble detail. However, what might be described as a pleasantly ‘organic’ sound can have its balance tipped by the speaker. Its coupling with the DALI Rubicon 2s appeared a little lighter-sounding than usual, for example.

If it wasn’t for Damon Albarn standing in as producer, Bobby Womack’s The Bravest Man In The Universe [XLCD561] wouldn’t have sounded like the album it does. Or even existed, as the soul crooner seemed to be fin de carrière until he met with Albarn on the Gorillaz project. Fortunately, the record came to be, and contains some fabulous tracks, including ‘Dayglo Reflection’ featuring the backing vocals of Lana Del Rey. Here, the RA280 floated her typically languid voice above the electronic beat and grittier lines sung by Womack.

https://www.stereophile.com/content/balanced-audio-technology-rex-500-power-amplifier

I decided to evaluate the amp in three ways. First, I went without a preamp, using the volume control of my main source, an Aurender A20 digital transport and server. Then I listened to the REX with the Aurender connected via the line stage of my Benchmark HPA4. Finally, I pressed the VK-90 into service, again using the A20 as a source.

While I did indeed prefer the sound with the BAT preamp in the chain by a small margin, I spent the least amount of time with that combination because I wanted to home in on the sonics of the REX without the wild card the VK-90 presented.

BAT co-founder Steve Bednarski told me he’s keen on listening with a preamp in the system. I asked him why: What’s the downside to feeding a power amp the output stage of a DAC or other digital source? “A well-designed active line stage will provide greater current delivery from its output stage than almost any source omponent,” Bednarski emailed back. “Current delivery gives a sense of liveliness and joie de vivre to the reproduction of music. For instance, a CD player that uses an op-amp–based output stage will provide weak current delivery. When such an output stage is connected directly to an amplifier, the music can sound flat and uninvolving.”

https://www.hifichoice.com/content/rotel-michi-x5

The X5 comes across as rather more programme-dependent tan the X3, even if it’s hard to pinpoint exactly why. With the Jared Sacks recording of the Oyster Duo’s Stolen Pearls recital there’s the odd effect of Nicky Schwartz’s double-bass dominating the piano of his wife, Anna Fedorova, and for all the weight and resonance of the double-bass here, the two sound like they’re playing some way away with the surrounding acoustic tending to swallow them up. Of course, sometimes this slight lack of ambience can help – or at least change – the sound of a recording. For example, John Challenger’s beautiful Salisbury Meditation recital is curated from 270 hours of live recordings made while the newly-restored organ was played in Salisbury Cathedral during the on-site Covid-19 vaccinations – the ambience of the instrument accompanied by the hushed bustle going on down in the cathedral’s nave. Via the X5, there’s still a fine sense of the instrument in the lofty space, but that rustle of atmosphere is somewhat diminished, which is a good thing for focus on the playing, but it may rob the recordings of a little of their magic.

Rather than testing total harmonic distortion at full scale at 1kHz as many do, I prefer to understand what the amplifier is doing over a broader range of frequencies and at a more reasonable output level. So, I do a frequency sweep from 10Hz to 20kHz at 5 watts RMS into 8Ω instead. For reference, 5 watts will usually produce somewhere between 85-105dB sound pressure level depending on the connected speaker’s efficiency. I personally find 85dB to be quite loud for extended listening sessions. (I usually listen in the 75-80dB range for longer sessions to protect against hearing damage.) At 5-watt levels, we see that total harmonic distortion is dominated by 3rd-order products up to about 2.5kHz where 2nd-order distortion takes over. At 20kHz, distortion is about 0.04% which is very close to the manufacturer’s published <0.03% THD.