Most high-performance modern DAC ICs have differential outputs, even those targeting single-ended consumer applications. It’s a great way to reduce even-order nonlinearities in the chip’s conversion and output stages, and it gets you around 3dB better SNR.
But in most systems that support both “balanced” (i.e., differential) and RCA (i.e., single-ended) outputs, there is an existential battle between the two for primacy.
In the third installment of this series, I want to talk about one of the device types you’re almost guaranteed to encounter in low-voltage audio: the rail-to-rail opamp. More specifically, I want to talk about the terminology around rail-to-rail opamps and the techniques used by IC designers to achieve rail-to-rail behavior. So let’s start by answering a fundamental question.
A few years ago, I developed an audio gain cell that was exceptionally fast for a fully discrete circuit and quite clean. That design ended up being adopted commercially, including by Audio by Van Alstine, who are using it in their DAC MK 5 and Vision preamplifier. I like to think that this gain cell is a key factor behind why the owner of a well-regarded manufacturer of luxury loudspeakers called the AVA DAC MK 5 one of the best sounding DACs he’d ever heard and a model for other manufacturer’s to live up to.
In an earlier post, I talked about how I entered the world of low-voltage audio and my commitment to delivering the best possible performance subject to that constraint. In this post I’d like to consider some strategies for generating power in your LV application.
I just discovered that I got a mention in Doug Self’s book The Design of Active Crossovers for the work I did a while back on loudspeaker crossovers. If you don’t know who he is, he’s one of the big names in British audio engineering. He’s done work for Cambridge Audio, TAG-McLaren Audio, and other respected brands. Feeling warm and fuzzy.
Single-ended amplifiers, whether made with triodes (as in the single-ended triode, or SET, amplifier), pentodes, or solid state devices, entered the high-end consumer audio consciousness a couple decades ago, and they continue to have a particular pull for a certain camp of audiophiles. This may lead some of us to wonder whether these folks are onto something that we should pay attention to.
However, there seems to be some confusion regarding what exactly single-ended amplifier are. So I thought I’d try to clear things up a little.
This project pushed “constraints as creative resource” to the limit. The client specified that the design language and elements from the product’s predecessor be maintained—down to the knobs, faceplate treatments, and typography.
The project brief revolved around electronic and industrial design work to bring the client’s preamplifer platform up to functional parity with current market offerings within a framework that fits with the client’s existing manufacturing capabilities. The result is a platform that is significantly more capable than what it replaces yet easier for the client to manufacture. It is also amenable to comprehensive appearance changes if and when the client deems the timing is right.
So while it might not seem there’s much innovation on the outside, there is a lot of innovation for the client on the inside.