Author Archives: John Atkinson

We began issuing recordings on the Stereophile label on the finish of the Eighties, each to make out there a few of take a look at tracks that we had been utilizing in our critiques and to allow readers to have entry to recordings the place the provenance was absolutely documented. That means the “Circle of Confusion” that Bob Katz mentioned on the Stereophile web site in 2017, the place the sound high quality of an audio part could not be judged utilizing a recording with unknown sound high quality potential, might be prevented. As Bob wrote, “How can any reviewer make a judgment a couple of transducer with out figuring out what a recording is meant to sound like?”

In 2017 we launched Tight Lines, an album of classical chamber works that had been composed by Sasha Matson. I had produced Tight Lines, as I had Sasha’s Cooperstown, a jazz opera about baseball, which was launched on Albany Records and was Stereophile‘s “Recording of the Month” for April 2015.

Working with Sasha and with famend engineers like Mike Marciano, Bill Schnee, and Michael C. Ross on these initiatives had been extraordinarily fulfilling. So when Sasha approached me within the spring of 2021 about producing an album of classical-themed works he had composed for a jazz massive band, I did not must be requested twice.

The works we had been to file had been a piano concerto, a symphony, and a tribute to Grateful Dead guitarist Jerry Garcia. Here is how Sasha described the works within the LP sleevenotes:

“Concerto For Piano & Jazz Orchestra options soloist Adam Birnbaum, with whom I first mentioned the piece at The Village Vanguard in New York. Adam has been a member of the Vanguard Jazz Orchestra in recent times, which supercharges that small stage on Monday nights. I thank him for serving to to woodshed the rating and elements for this composition—and for taking part in the heck out of it!

“Capt. Trips is devoted to the reminiscence of Jerry Garcia. Coming up via center and highschool within the Sixties in Berkeley, we regarded to members of The Grateful Dead as our massive brothers—as position fashions! I’m happy that guitarist Steve Cardenas introduced his personal sound to bear right here, summoning Garcia from the Isle of the Dead.

“Symphony No.3 For Jazz Orchestra started as sketches a few years again, after I participated within the BMI Jazz Composers Workshop, at the moment run by Andy Farber and Ted Nash. I thank them each for selecting up their horns and pitching in. The title of the fourth motion, “Life Against Death,” is borrowed from a guide of that identify by Norman O. Brown, who taught at UC Santa Cruz after I was a scholar there.”

The album, Molto Molto, is now out there on the Stereophile label with the catalog quantity STPH023 as a double-LP, 180gm set ($39.95) and a single CD ($14.95). The album might be bought from Amazon and later this week from Stereophile‘s Online Store.

Molto Molto might be streamed as 24/96 FLAC recordsdata on Qobuz, as 16/44.1 FLAC recordsdata on Tidal, and as lossy compressed 16/44.1 recordsdata on Spotify. Excerpts might be auditioned on Amazon and at Sasha Matson’s web site.

We began issuing recordings on the Stereophile label on the finish of the Nineteen Eighties, each to make accessible a few of check tracks that we have been utilizing in our critiques and to allow readers to have entry to recordings the place the provenance was totally documented. That manner the “Circle of Confusion” that Bob Katz mentioned on the Stereophile web site in 2017, the place the sound high quality of an audio part could not be judged utilizing a recording with unknown sound high quality potential, might be prevented. As Bob wrote, “How can any reviewer make a judgment a few transducer with out understanding what a recording is meant to sound like?”

In 2017 we launched Tight Lines, an album of classical chamber works that had been composed by Sasha Matson. I had produced Tight Lines, as I had Sasha’s Cooperstown, a jazz opera about baseball, which was launched on Albany Records and was Stereophile‘s “Recording of the Month” for April 2015.

Working with Sasha and with famend engineers like Mike Marciano, Bill Schnee, and Michael C. Ross on these tasks had been extraordinarily fulfilling. So when Sasha approached me within the spring of 2021 about producing an album of classical-themed works he had composed for a jazz massive band, I did not must be requested twice.

The works we have been to file have been a piano concerto, a symphony, and a tribute to Grateful Dead guitarist Jerry Garcia. Here is how Sasha described the works within the LP sleevenotes:

“Concerto For Piano & Jazz Orchestra options soloist Adam Birnbaum, with whom I first mentioned the piece at The Village Vanguard in New York. Adam has been a member of the Vanguard Jazz Orchestra lately, which supercharges that small stage on Monday nights. I thank him for serving to to woodshed the rating and elements for this composition—and for taking part in the heck out of it!

“Capt. Trips is devoted to the reminiscence of Jerry Garcia. Coming up via center and highschool within the Nineteen Sixties in Berkeley, we appeared to members of The Grateful Dead as our massive brothers—as position fashions! I’m happy that guitarist Steve Cardenas introduced his personal sound to bear right here, summoning Garcia from the Isle of the Dead.

“Symphony No.3 For Jazz Orchestra started as sketches a few years again, once I participated within the BMI Jazz Composers Workshop, at the moment run by Andy Farber and Ted Nash. I thank them each for choosing up their horns and pitching in. The title of the fourth motion, “Life Against Death,” is borrowed from a e-book of that title by Norman O. Brown, who taught at UC Santa Cruz once I was a scholar there.”

The album, Molto Molto, is now accessible on the Stereophile label with the catalog quantity STPH023 as a double-LP, 180gm set ($39.95) and a single CD ($14.95). The album will be bought from Amazon and later this week from Stereophile‘s Online Store.

Molto Molto will be streamed as 24/96 FLAC recordsdata on Qobuz, as 16/44.1 FLAC recordsdata on Tidal, and as lossy compressed 16/44.1 recordsdata on Spotify. Excerpts will be auditioned on Amazon and at Sasha Matson’s web site.

Although NAD was based in England in 1972 as New Acoustic Dimension, my introduction to the model was in 1980. I purchased an NAD 3020 built-in amplifier after listening to it efficiently drive Acoustic Research’s current-hungry AR9 loudspeakers. Designed in England by Bjørn-Erik Edvardsen (footnote 1) and manufactured in Taiwan, the ridiculously cheap 3020—it price simply $135 again then—confirmed that an amplifier did not want machined faceplates, intimidating heatsinks, or technically glamorous parts to have the ability to drive real-world audio system. In 2002, the 3020 was nominated by Stereophile‘s writers and editors as one of many 100 most vital audio merchandise within the journal’s first 40 years (footnote 2).

NAD was little identified in 1980, however the 3020 put the model on the map, the corporate promoting 1.1 million models over the amplifier’s lifetime. NAD subsequently went by way of possession modifications and in 1999 was bought by Canada’s Lenbrook Group, the model’s Canadian distributor since 1978.

Stereophile has favorably reviewed many NAD amplifiers over the many years. One of the latest was the Master Series M10 class-D streaming built-in amplifier, which I bought to make use of as my every day driver after I reviewed it in January 2020. The M10’s value included a free license for Dirac Live low-frequency room equalization, which I discovered invaluable with my long-term reference standmounts, the KEF LS50s. So after I discovered that NAD was introducing a fiftieth Anniversary built-in amplifier, the C 3050 LE, which additionally included Dirac Live, I requested for a overview pattern.

The C 3050 LE (Anniversary Edition)

The LE within the amplifier’s title stands for Limited Edition—simply 1972 samples might be offered at a US value of, you guessed it, $1972. (1972 was, as talked about above, the 12 months of the corporate’s founding.) The value consists of an MDC2 BluOS module. (There might be a non-LE model, which is able to price $1899 with the BluOS module, $1299 with out it.)

With its wood-grain vinyl wrap, the cursive-font “New Acoustic Dimension” brand on the entrance panel, and its twin, illuminated VU meters, the amplifier’s styling is distinctly retro, resembling that of the NAD 3030 amplifier from 1976. Inside, nonetheless, the C 3050 LE is completely trendy. The BluOS module permits audio to be streamed from native storage on the proprietor’s community or from Tidal, Qobuz, Amazon Music Ultra HD, Deezer, TuneIn radio stations, and different streaming providers,with digital decision as much as 24bits and a pattern price of 192kHz. MQA unfolding is supported. Audio will be streamed from iOS units with Apple AirPlay 2, and the BluOS module works with the Spotify Connect and Tidal Connect apps. Music may also be streamed from cell units to the amplifier or from the amplifier to wi-fi headphones with two-way Bluetooth aptX HD. Playback will be voice-controlled utilizing Amazon Alexa, Google Assistant, or Apple’s Siri. An IR distant management is offered, and multiroom operation and integration with sensible home-control programs is supported.

BluOS is an app-based multiroom “music ecosystem” (assume Roon) which supplies entry to your personal content material and integrates a lot of music providers—not simply the same old suspects like Tidal and Qobuz but in addition some obscure ones, comparable to nugs.web, IDAGIO, and Bugs, which is out there solely in South Korea. If a streaming service is not accessible, you’ll be able to ship it to the C 3050 LE with BlueTooth or AirPlay.

The C 3050 LE accepts knowledge by way of HDMI eARC, Type A USB, and coaxial and optical S/PDIF inputs. The C 3050 LE’s D/A circuit makes use of Texas Instruments PCM5242 differential-output DAC chips. These can decode PCM knowledge as much as 32 bits and 384kHz, although the amplifier’s playback is restricted to 192kHz. Installed on the decrease left of the again panel is the MDC streaming module (however non-obligatory on the forthcoming non-LE model) with an Ethernet port, mounts for the included Bluetooth and Wi-Fi antennas, a service port, and a USB-A enter to attach a reminiscence stick or “supported peripherals.” The Gigabit RJ45 (Ethernet) enter helps sampling charges as much as 192kHz and bit depth as much as 24. Analog inputs embrace one pair of line-input RCA jacks and one pair of RCA jacks for MM phono enter; all are digitized by the C 3050 LE, and RIAA correction is carried out digitally. Jumpers join a pair of single-ended preamp output jacks to single-ended amplifier enter jacks. The offered subwoofer output will be adjusted with the BluOS app, and there is a ¼” headphone jack on the entrance panel.

Front-panel controls enable the person to regulate treble and bass—these will be bypassed with the BluOS app—in addition to steadiness and quantity. A rotary change selects both or each loudspeaker outputs, turning them off for headphone listening. The C 3050 LE’s energy amplifier stage makes use of HybridDigital UcD class-D modules and the utmost steady energy is specified as 100Wpc into 8 or 4 ohms; instantaneous most energy is specified as 180W into 8 ohms, 250W into 4 ohms, and 300W into 2 ohms.

Setup

Installation of the C 3050 LE was easy. I linked its Ethernet port to my community and arrange its Wi-Fi connection. I put in the BluOS app (v.3.20.2) on my iPad mini 2 (above) and used this to examine that the amplifier’s firmware was updated. I then logged into my Qobuz and Tidal accounts. The BluOS app positioned and listed the audio library I exploit with my Roon Nucleus+. (Though the Roon app acknowledged the NAD, it reported that “the producer has not but accomplished certification for this gadget.”) I linked the single-ended analog outputs of my Ayre Acoustics C-5xe^MP disc participant to the NAD’s line inputs with Canare interconnects, the participant’s AES3 output to the TosLink enter by way of a Z-Systems RDP-1 used as a format converter. The NAD’s speaker outputs have been linked to my KEF LS50s with AudioQuest Robin Hood cables.

A rear-panel change selects whether or not the C 3050 LE’s front-panel meters present the enter or the output sign ranges, set with a back-panel change. I caught with the previous. The amplifier’s quantity setting is indicated with a row of LEDs on the suitable of the entrance panel. The leftmost LED is orange, and inexperienced LEDs successively mild as much as its proper as the quantity is elevated. A button on the distant management permits these LEDs to be dimmed, however even on the lowest setting, they’re nonetheless vivid. Fortunately, they are often turned off utterly. The VU meters stay illuminated.

NAD says that the MDC2’s two-way communications enable Dirac Live to work with all sources linked to the C 3050 LE. To use Dirac Live with the amplifier, I plugged the included microphone into the three.5mm jack on the also-included USB adapter then plugged that into the C 3050 LE’s USB Type A port. I put in the Dirac Live app (above) on my Mac mini, after first ensuring that it and the C 3050 LE have been linked to the identical Wi-Fi community. The app discovered and recognized the amplifier as “C 3050 – 0184n.” I then adopted the on-screen directions for “tightly centered imaging,” inserting the microphone in every of the 9 positions specified by the app and performing a “chirp” take a look at at every. Dirac then calculated a correction filter working under 500Hz (under) and requested first for it to be named, then to be saved to one of many 5 slots within the C 3050 LE’s DSP reminiscence. When I ran the BluOS app on the iPad, the Audio Settings menu now included an on/off change for the Dirac filter. With Dirac lively, there was a 10dB discount in stage, presumably to maintain the equalized digital sign from exceeding 0dBFS.

Footnote 2: Also see en.wikipedia.org/wiki/NAD_3020.

Stereophile‘s March 2023 issue includes two follow-up reviews of high-performance digital playback products: the Benchmark DAC3 B D/A processor; and the Rotel Diamond Series DT-6000 DAC Transport (a CD player with digital inputs).

When he reviewed Benchmark’s DAC 3 HGC D/A processor/headphone amplifier in the November 2017 issue of Stereophile, Jim Austin was impressed by what he heard, as was I by its measured performance. “This is as good as a DAC can currently get!” I wrote. So when I was given the opportunity to live with the stripped-down DAC3 B version, which costs $1799, significantly less than the HGC’s $2299, I jumped at it. You can find my thoughts on its sound here.

In his Gramophone Dreams #69 column, Herb Reichert described the Rotel DT-6000 as a “well-built, great-sounding, reasonably priced CD player.” He had so much fun using the Rotel—”rediscovering the Joy of CDs: one-box simple, stress-free, plug’n’play, and something physical to touch, scrutinize, and collect”—that he suggested I examine its measured performance. You can find my measurements here.

“A 10″ two-way?!?!” I couldn’t help gasping in surprise when I unboxed the MoFi Electronics SourcePoint 10 standmounted loudspeakers, which cost $3699/pair.

Some background is in order. Using a large-diameter woofer endows a conventional two-way speaker with potentially high sensitivity and extended low frequencies. However, the large woofer’s radiation pattern narrows at the top of its passband, whereas that of a tweeter mounted on a flat baffle is at its widest at the bottom of its passband. Even if the drive units’ outputs are well-matched in the speaker’s on-axis response, this discontinuity in the speaker’s off-axis behavior results in an in-room balance that will sound bright. This is why favorably reviewed two-way designs tend to use a woofer with a 6.5″ or even smaller diameter.

But …

The SourcePoint 10 was designed by Andrew Jones, a well-respected veteran loudspeaker engineer with highly regarded models from KEF, Infinity, Pioneer, TAD, and ELAC in his resumé (footnote 1). Andrew, who is now celebrating two years with MoFi, has indeed done something different with his first design for the company.

The SourcePoint 10
The first thing you notice about this speaker is that the sculpted, 2″-thick front baffle has a single, centrally placed drive unit with a 1.25″ soft-dome tweeter mounted concentrically at the center of the 10″ woofer’s paper-pulp cone. The second thing you notice is that instead of a conventional half-roll rubber surround for the cone, the woofer, which is reflex loaded with twin ports on the rear panel, uses an old-fashioned corrugated surround. The third thing you notice is that this is a large, heavy design for a standmount; it measures 22.5″ × 14.5″ × 16″ with an internal volume of 50l—that’s 13.2 gallons—and weighs just over 46lb.

Andrew Jones and MoFi’s Jon Derda visited the day after I unboxed the SourcePoint 10s. As they prepared to set up the speakers in my room, I asked Andrew why he had settled on a two-way concentric design rather than a three-way and why, considering that, he had decided to use such a large woofer (footnote 2).

“Pretty much 100% of the designs I’ve done with concentric drivers have been three-way. And that’s because with a concentric driver, you don’t want the cone moving too far. The more movement you allow it to have, the more compromises you’re getting, because you get amplitude modulation. … You also need a bigger surround, [which] disrupts the wavefront from the tweeter, [and the] delayed reflection off the cone causes differences in the frequency response.

“The problem [with a three-way] is the complication, the extra cost, … and trying to pick the frequency where you should cross over” from the woofer to the midrange. “Should it be as low as 80Hz? That would be very, very costly to do in terms of parts costs for a passive crossover. And how far down do I want to take that midrange, especially given its size and everything I need to do to control how well it works as a waveguide for the tweeter? So, could I do a two-way concentric? Because if I’m concerned about minimizing movement of the cone in a concentric, there’s only two ways to do it. One is to restrict the frequency ranges, which is what you do when you turn it into a three-way. Or you make the woofer so big that most of the time it doesn’t have to move hardly at all. Going from a typical 4.5″ or 5″ driver to a 10″, I’ve got nearly four times the area and a quarter of the movement, which is significant.

“Because one of the briefs from MoFi was to have good, impactful, and extended bass. As well, as it’s getting back into fashion to have big woofers, it would be fun to work with a big woofer. That could be cool, but I’d never done one before.”

I asked how, in a two-way design with a 10″ lower-frequency driver, which will start beaming at a relatively low frequency, does he match it to the wider dispersion of a tweeter?

“When you put the tweeter in a waveguide, it’s not that it’s narrowing the directivity everywhere. It’s narrowing it at the lower frequencies, which is where you have the problem in matching the directivity to the woofer. So now you’re going to narrow it progressively as you go down in frequency, correlating with how much sensitivity you gain due to the waveguide loading at the lower frequencies. With a good waveguide, you can reach about +10dB of on-axis output compared to no waveguide. And that’s a huge advantage for working the tweeter because 10dB is a 10th of the power input you need in a critical range where there’s still a lot of energy in the music. The waveguide … reduces the energy input, the thermal compression, and the excursion requirement [of the tweeter].

“So if you can engineer a low resonant–frequency tweeter, you can run it down to a lower frequency”—it’s 1.6kHz in the SourcePoint 10—”because it’s running at a lower excursion compared to not having a waveguide, which more than makes up for the extra extension that you need to cross over the tweeter lower. And with a 10″ waveguide, the improvement in efficiency or sensitivity and the reduction in excursion more than make up for the fact that you’re crossing over at 1.6k. It enables you to get a very good, progressive, consistent off-axis performance.

“When the waveguide also needs to be a woofer or midrange cone, you’ve got to decide what is the best shape for it to act as a waveguide and what is the best shape for it to act as a cone, with controlled cone resonances. You hope that it’s the same shape. So there’s a choice of sizes and materials and everything else to optimize both the shapes simultaneously. So I started designing waveguides and getting them 3D-printed to see, what were the directivity characteristics? I came up with a shape that seemed to work very well. So the next thing was, okay, so now I have a cone that’s going to work and need a surround. I knew I couldn’t have a half-roll surround because that would disrupt the [tweeter’s] wavefront. So it’s got to be one of these corrugated surrounds like they use on pro speakers.”

I asked Andrew why he had chosen a paper cone for the woofer. Wouldn’t a 10″ paper cone break up at a low frequency?

“About 3kHz. It’s very smooth up to that frequency if you have the right curvature and the right pulp. So I tooled up some cones, tooled up some surrounds, got a sample built, which sounds easier than it actually was. … It took a long while before I had anything that I could start listening to.”

We discussed the MoFi’s soft-dome tweeter, which, as well as being larger than usual for a two-way design, has a relatively large surround. Andrew explained that the surround acts as a ring radiator, emitting sound. He said that with a conventional tweeter, the surround’s output at very high frequencies may well be in the opposite polarity to that of the dome, resulting in a loss of output. “I knew I wanted a slightly larger diameter, 1.25″ rather than 1″, with a wide roll surround, because that gives you extra capability at the lower frequencies. Counterintuitively, if you put a wider roll surround on the tweeter, you actually improve HF response. You think it would interfere and cut off earlier, but it doesn’t; it actually extends it. … [T]he phases will be additive up to a higher frequency.” Andrew said the SourcePoint 10’s tweeter goes out to beyond 30kHz.

Footnote 2: A white paper on the design of the SourcePoint 10 can be downloaded here.