Integrated Amp Reviews

Technics, an arm of the Japanese giant Panasonic Corporation, has long been a major player in the hi-fi world, even if, in some recent decades, it stayed below the radar.

In the 1970s, analog-centric audiophiles particularly praised the Technics SP-10, the world's first direct drive turntable. Created by Matsushita engineer Shuichi Obata in 1969, the SP-10 and its successors became the standard in vinyl playback for American radio stations during that heyday of broadcast radio. Because of its powerful motor, the SL-1200 became the spinner/scratcher of choice among hip hop DJs soon after its 1972 introduction; Grandmaster Flash, Kool Herc, and Grand Wizard Theodore are among the hip hop DJs who favored the SL-1200. (The latter is said to have invented the scratching technique.) Later versions of the SL-1200 maintained an important cult following among analog audiophiles.

Both 'tables continue in use today, and new versions of both were introduced in recent years, the SL-1200 G in 2016—the 50th anniversary of the SL-1200—and the SP-10R in 2018.

Even if the Technics story ended with turntables, its spot in hi-fi history would be secure. But it doesn't. 1965's Technics 1 loudspeaker advanced the design of sealed-box loudspeakers.

In 1966, the company introduced the 10A tubed preamplifier and 20A stereo power amp, the latter an OTL design that output 30Wpc into 8 ohms and 60Wpc into 16 ohms using 20 pentode tubes. Technics brought "linear phase design" to 1975's Technics 7 loudspeaker, an "isolated loop system" to 1976's RS-1500U reel-to-reel tape deck, and a class-A platform in 1977's SE-A1 DC power amplifier. Most important of all, Technics's solid and affordable receivers, turntables, and cassette players were enjoyed by pretty much every music lover of modest means who grew up in the 1970s and '80s.

The SP-10R and SL-1200G turntables were introduced soon after what Panasonic called the Technics relaunch, which commenced in 2014. There was also the SU-R1 Network Audio Control Player and the SE-R1 Digital Amplifier, which incorporated the "JENO (Jitter Elimination and Noise-shaping Optimization) Engine," "LAPC (Load Adaptive Phase Calibration)," and GaN (gallium nitride) FET driver transistors. 2017's SU-G700 Digital Integrated Amplifier introduced "High-speed Silent Hybrid Power Supply." Judging by these and other trademarked descriptors, the new Technics started to look like a high-tech innovator.

For sheer technological boldness, none of these other Technics products could match the SU-R1000 Digital Integrated Amplifier ($9499).

Why bold? The SU-R1000 digitizes all incoming signals, including those headed to its phono stage; that will ruffle the feathers of some and fascinate others, but it makes possible some manipulations that cannot be done in the analog realm. The SU-R1000 includes the LAPC and JENO Engine and adds ADCT (Active Distortion Cancelling Technology), AS2PS (Advanced Speed Silent Power

Supply), and four independent GaNFET (Gallium Nitride Field Effect Transistor) power supplies, one each for analog and digital processing, one each for the left and right output stages. The SU-R1000 allocates three distinct processing functions in the phono stage alone, naming the cumulative result Intelligent Phono EQ. See below for descriptions of the new Technics techniques.

Technical features
The R in SU-R1000 stands for Reference Class, alluding to this whole line of Technics Reference components. It's the same "R" that's in the SP-10R.

Some companies that make class-D amplifiers are content to have their technology labeled class-D—just don't call it digital. Technics is happy to have the amplification technology in the SU-R1000 called digital—in fact they insist on it—just don't call it class-D!

"Technics' digital amplifier is often mistaken as class-D, but strictly speaking, Technics' digital amplifier is not class-D," company CTO Tetsuya Itani writes in a Technics white paper. "Class-D ... is a ... method that applies analog signal technology such as sawtooth wave generation and comparator, so it has the drawbacks of conventional analog amplifiers, such as the possibility of distortion and noise mixing, depending on the accuracy of parts, etc. Further, since the input is an analog sound signal, it is necessary to [perform] D/A conversion on the digital signal, and there is a limit to accuracy in handling a high-precision signal such as high-res sound. Technics' full digital amplifier processes digital input as it is with high precision, so it is advantageous, especially when handling high-res signals. When dealing with analog signals, a 192kHz/24bit high precision A/D converter is used to ensure high performance." To perform this task, the SU-R1000 utilizes the AK5572EN 1740EAC ADC chip from AKM.

The following explanations of the SU-R1000's processing functions were based on a recent webinar focused on the SU-R1000; email conversations with Frank Balzuweit, Technics's business-development manager for consumer electronics; and online sources.

The JENO engine
"JENO" is short for "Jitter Elimination and Noise-shaping Optimization."

"To eliminate the degradation of sound caused by jitter, Technics has developed an original jitter reduction circuit"—the JENO engine—"comprising a clock generator in the noise-shaping system to reduce jitter in the low-frequency range and a high-precision sample rate converter for suppressing jitter in the high-frequency range. Thus it reduces jitter in an ideal way over the entire frequency range."

The JENO engine is employed during the conversion of PCM signals into PWM—pulse-width modulation, similar to the technology behind DSD. "In the JENO Engine, there is a low-jitter sample rate converter, lifting all incoming signals to 32-bit/768kHz PWM," Balzuweit explained in an email. "Then 1-bit conversion is performed in the Delta-Sigma converter to form an intermediate signal as a preparation to drive the output transistors."

"After the Delta-Sigma converter," he continued, "there is another stage, the PWM converter, which forms a so-called 'ternary' (2-bit) signal out of the 1.5MHz 1-bit signal. So, each transistor only has to handle a switching speed of 768kHz/1-bit, which is easier to handle in terms of the natural response time of a GaNFET. "This is an important bit: gallium nitride field-effect transistors—GaNFETs—are capable of higher switching speeds with low distortion and little ringing. "Actually, the two signals of 768kHz/1-bit are overlapping: Each one addressing either the + or the – driver effectively work as a 1.5MHz, 1-bit (binary) signal. There is no D/A conversion needed to drive the speakers. The data flow of the ternary output is driving the speakers directly."

What's ADCT?
ADCT is short for Active Distortion Cancellation Technology. "ADCT addresses the distortions at an amp's output caused by the back electromotive force of the speakers," Balzuweit wrote. "You can apply negative feedback to the input, but this is only partially effective and negatively affects transients. With ADCT, we extract the distortion caused by the back electromotive force. The output signal, which is analog, is digitized and then calibrated. As [that] signal has high level, it is reduced in gain and purified [of] eventual DC offset. The resulting signal then is compared with the pure, undistorted signal directly at the JENO Engine's output. Both signals are subtracted, the result is the distortion part only! This signal part is fed back with [a] negative signal to the JENO's input, and distortion is thereby effectively eliminated. We aren't feeding back the full music signal, only the distortion. This is unique, and you can never ever do the same on an analog linear amp."

And LAPC?
LAPC stands for Load Adaptive Phase Calibration. It uses DSP to "measure output gain and impedance phase characteristics of the amp and speaker, creating an ideal impulse response for any speaker," Balzuweit told me. LAPC is measured and implemented using a series of test tones enabled by pressing the remote's LAPC button. It seems to resemble Devialet's SAM—short for "Speaker Active Matching"—although there are some obvious differences.

AS2PS
AS2PS, or Advanced Speed Silent Power Supply, refers to the SU-R1000's switching power-supply technology, which is said to be much quieter and stabler than typical analog power supplies. The SU-R1000 has four power supplies—one for analog, one for digital, and one for each output stage—separated and shielded by steel divider plates, which help block interference and further reduce transmitted noise.

Intelligent Phono EQ
Perhaps the SU-R1000's most radical technology is reserved for the oldest medium the amplifier supports. Intelligent Phono EQ comprises three features: Accurate EQ, Crosstalk Canceller, and Response Optimizer. Technics calls it a "hybrid" system: "The high-gain low-pass filter (LPF) performs analogue processing, while high frequencies are raised after the A/D conversion." The SU-R1000 offers a choice of seven EQ curves: RIAA, Decca/London, Columbia, AES, IEC, NAB, and RCA.