Ken Davis, our sales manager, is smitten with the Technics SU-R1000.
What does your microwave have to do with your class-D amplifier?
The Technics SU-R1000 is packed with technology, and Ken Davis, our sales manager, dives deep in his video, even saying "Gallium Nitride Field Effect Transistor" with barely a flinch. But the video's most important takeaway is when he says, "Don't get lost in the specs; don't get lost in the technology."
"We were pulling people away from their desks," says Ken, describing the scene in the office as the SU-R1000 played in a demo room. "We were saying, 'I don't care what you're doing, come listen to music."
That's the magic of the Technics, but even so, it would be a pity not to delve into the included technology. However, before getting into LAPC, JENO Engines, and phono calibration, here's a basic primer on how class-D amps work.
Your Oven, But Faster
Many people don't realize that irons, microwaves, ovens, ACs, and heaters don't have power levels. They are either off or 100% on. To get "power levels", they cycle between the two states at different rates, so at half power, they are on as much as they are off, in other words, a 50% duty cycle. At very low levels, they're simply off more than they're on. You can hear this with your microwave on the defrost setting, where the magnetron buzzes only briefly, with long gaps of just motor and fan hum in between.
Since your microwave or AC can turn on and off only so quickly, we're talking about cycles that are well below 1 Hz, often measured in minutes rather than seconds. Increase this on-and-off ability to 150,000 times a second or more (in Technics' case, to 400,000 Hz), and you can now create many "power levels" with tiny jumps between each. You now have enough shades of "on-ness vs. off-ness" to replicate the sine waves of a music signal, and this is exactly how the output stage of a class-D amp works (with some filtration to smooth everything out, and vastly more complexity than we suggest here.)
The Technics SU-R1000 might be packed with technology, but it's also a joy to listen to and interact with.
Digital All the Way
The digital representation of being switched on and off at high speed to represent different power levels is called pulse width modulation (PWM). The higher the point on a sine wave that's being represented, the wider the pulse (the longer the output circuit stays on). Most class-D amps convert the analog music signal into a PWM signal near the output stage, and use that to drive the output transistors. This means a PCM or DSD digital input must be converted to analog, go through the amp's input and gain stage, and then be converted back into digital (PWM) for the output.
Technics had the great idea to create a "digitally controlled class-D" amp, meaning that a PCM or DSD signal from your streamer is never converted to analog, so you don't get any artifacts from that process. It is converted only in a final D2D process to PWM for the output stage. This means tremendous accuracy and directness in the sound, and this is why Ken is so thrilled with the Technics SU-R1000.
Does My Analog Become Digital?
Short answer, yes. A turntable connected to the Technics SU-R1000 will have its analog signal converted to digital. Is this a problem? Depends on you.
Sharp-eyed readers of the previous article will see that in a "digitally controlled class-D amp," all analog input signals are converted early on to digital. (In any class-D amp they are eventually converted to a pulse width modulated digital signal).
So, yes, the signal through the Technics SU-R1000's on-board phonostage is converted to digital and stays digital. Is this a problem? That depends on your point of view. On the one hand, we respect and understand wanting to keep your analog signal in the analog domain. Many of us here are of the same mind.
On the other hand, getting too militant about "analog vs. digital" raises uncomfortable questions about whether any music today has not, at some point, been digital in the loooong chain from studio microphone to home speakers.
If you're open to the idea of using the Technics amp with a turntable, you should know that Technics puts this digital conversion to full use by offering a calibration LP and then using DSP to compensate for cartridge crosstalk and frequency non-linearities.
But if one of vinyl playback's biggest attractions to you is that it is analog, know that the SU-R1000 quickly converts analog to digital in the phonostage: The cartridge's signal goes through an analog high-gain low-pass filter after which it is converted to digital for high-frequency processing and the application of crosstalk correction and phono optimization DSP.