With the launch of LG V20 in India, “Quad” DAC term has led to a fair bit of confusion. With some wondering if LG is counting the number of outputs, or if there’s multiple DACs for different audio paths. I assure you that this isn’t the case, but a proper explanation is far more complicated. So without getting into complexity,I’ll try to explain (also keeping it as easy as possible) what exactly is “Quad” DAC or Hi-Fi DAC.
According to the press release – The ES9218 is a 32-bit 394kHz and DSD512 capable component, with some nifty sounding analog audio controls, jitter controls, and integrated headphone amplifier. The chip also promises 130dB SNR, 124dB DNR and -112dB THD+N to please audiophiles. Importantly, the release says that this is a stereo (2-channel) component with no mention of a differential output, so the quad output theory instantly goes out of the window. Even so, the release is still cluttered with references to this mysterious “Quad” technology. So let’s try and figure this out.
What does DAC Means?
DAC (Digital-to-Analog Conversion) takes digital data from your audio file and converts it into an analog waveform which can be sent to headphones or a speaker driver. The idea is to reproduce the analogue signal with as little added noise or distortion as possible.
Now, What is Quad DAC?
According to Mr. Ken Hong, global communications director for LG
The signals from each DAC path adds together but noise does not, resulting in higher signal with less increase in noise. Each doubling of converters results in half the decimation noise
In other words, it’s possible to improve the noise performance of a sigma-delta modulator (method for encoding analog signals into digital signals) further through the use of multi-order designs. This is pretty much essential if we want to produce a DAC that approaches or surpasses 16-bits worth of resolution for top-quality audio. Fortunately, clever engineers have come up with advancements to this core design that can greatly improve noise and resolution performance. Either through the use of higher-order, multi-bit, or multi-stage architectures, or a combination of the three. It’s the use of multiple sub-DACs that ESS is likely giving mention to with its Quad DAC title.