Located in Guangzhou, China’s third-largest city and the birthplace of Cantonese culture and language, Denafrips is focused on developing high-end-audio equipment at competitive price points. Since its inception in 2012, the company has grown to over 40 employees. The owner and founder, Mr. Zhao, has managed to assemble a team with deep knowledge of both analog and digital circuits. Almost everything is done in-house with full control over product quality and manufacturing costs. Global sales and marketing are handled by Alvin Chee of Vinshine Audio in Singapore, who also provides direction regarding specifications and quality control. Denafrips is best known for its own line of R-2R DACs, in which the $4498 Terminator currently sits second from the top, eclipsed only by the Terminator-plus.
For PCM digital-to-analog conversion, the choice of an R-2R design fits perfectly with Denafrips’ philosophy of emphasizing sound quality over measurements. According to Mr. Zhao, total harmonic distortion at levels lower than 0.003% has almost no perceptible effect; indeed, excessive pursuit of low distortion levels per se may have an adverse effect on sound quality. Therefore, his first priority is to minimize digital-conversion artifacts without exceeding this distortion guideline. The end result sought is smooth, analog-like sound quality.
The R-2R resistor ladders are discrete and contain about five hundred 0.005% precision resistors per channel for 26-bit resolution. The Terminator is capable of reproducing PCM up to 1.536MHz and DSD up to 45.2MHz (DSD1024) in native mode. The PCM digital-to-analog conversion scheme is based on sign-magnitude technology, which was introduced in the early 1990s by Burr-Brown in chip form. Such designs have also been referred to as “push-pull,” since there are two identical DAC sections per channel, with negative and positive polarity digital words being handled by separate sections. The net effect is to add and subtract voltage from the resistor ladder starting from the zero-crossing point, thereby resulting in smaller steps as bit switches are turned on and off. On average, the smaller step sizes result in less transient-induced noise and greater precision at low-levels. Execution is critical, so no expense was spared in the Terminator, as in deploying Crystek FEMTO clock oscillators designed specifically for high-resolution audio applications to ensure that the DAC clock is independent of the input signal.
Native DSD decoding is performed via a programmable FPGA and represents a complete break from the constraints imposed by traditional chip-based DSD bitstream decoding. All of the advanced number crunching, including oversampling and filter functions, is performed by a STMicroelectronics microcontroller running an ARM computer processor. The microcontroller is also used to implement a proprietary USB decoder, which, based on my listening tests, is far superior to the industry-standard XMOS solution. And that is great news, since the bulk of my digital files stream off my laptop through the USB input.
This is one beefy DAC, weighing in at 42 pounds. Essentially, all the weight is due to a massive linear power supply, featuring dual toroidal power transformers and ultra-low-ESR capacitors. The power supply is enclosed in a thick metal-alloy enclosure located underneath the DAC board, with an additional steel-plate divider between supply and DAC. There is a full gamut of digital inputs on the back panel, including USB, I2S, and every SPDIF type known to man. Both RCA and balanced XLR analog outputs are provided
The front panel is logically laid out. Selections are made via a series of pushbuttons. In addition to input source selection, mute, and phase reversal, oversampling (OS) or non-oversampling (NOS)modes can be toggled on and off. In OS mode, oversampling takes place up to 1.536MHz. DSD is converted in its native resolution with no upsampling. One of two digital filters (slow and sharp) may be selected for PCM playback via the mode button, though the initial default selection is the slow filter. There is no volume control or remote control. I didn’t object to having to change settings on the front panel manually, but with my limited vision, I found the status-indicator LEDs way too small and faint for comfort.
Original Resource is Articles – The Absolute Sound