The era of the analog preamplifier has come and gone and in its place we have a new class of product: a digital preamplifier – a term that may be new to you. First, a bit of history.
In days past when analog was king we needed a way to aggregate and control all our analog sources like turntables, tape decks, radio tuners and yes, CD players – as they too became just another analog source – despite the fact you placed a shiny silver digital disc in one end – what came out was analog no different than that of a radio tuner.
But today a growing number of our sources are purely digital in nature: CD/DVD transports, streaming media players, USB out from your computer, NAS drives, USB sticks with music on them etc. and so we also need a central place to aggregate and control all our digital sources. That class of product is currently called a Digital To Analog Converter or DAC – but it is more appropriately called a Digital Preamplifier – just people haven’t gotten their heads around this major paradigm shift we’re right in the middle of.
So we have moved from the need for managing a group of analog output devices to the need of managing a group of digital output devices. Central to this new paradigm is a fundamental change: instead of requiring every source to have a built in converter that outputs a proper analog signal, we now move to every source remaining in the digital realm with but a single converter at the output of the device. In other words, we now have but one analog converter accessed by many digital sources.
In fact, if you think about it, every DAC that’s ever been made was at least a multiple input switching device – where you could connect multiple digital sources aggregated on the rear panel and then select which of those to convert to analog – just like a preamp. All those earlier DACS lacked, to become a digital preamplifier, was a volume/balance control. Once that feature was added there was no reason to call it anything other than what it is, a Digital Preamplifier. Yet we all still cling to the term DAC – DAC with a volume control.
Change is tough but once we see the writing on the wall, we can all start to adjust.
Tomorrow I want to cover how the output stage of an analog preamp is pretty much identical to that of a digital preamplifier, thus removing another possible roadblock in our acceptance of the preamp paradigm in the digital age.
Paul McGowan – PS Audio, Intl.