DS1802 silicon potentiometer (2004)
AD844 common base I/V stage for TDA1541(A) DAC (2003)
I published this first as a part of my 2003 TDA1541A project. Despite its age, it is still highly recommended, both for its simplicity and exceptional sonic performance.
Distortion measurements of the AD844 common base I/V stage above (2004)
Discrete diamond non-feedback I/V stage for TDA1541(A) DAC (2004)
MAX436 based non-feedback I/V stage for TDA1541(A) D/A converter (2005)
The performance I initially found was inferior to that of AD844 and OPA861, and although I believed it was possible to improve on it, the MAX435/MAX436 went out of production, which discouraged further experiments. Still, it is a nice proof of concept that can also be implemented with discrete circuit(s).
Non-oversampling approach and analog filter design (2003, applies to 44.1 kHz sources)
Some of us took the problems with the low Fs non-oversampling approach very seriously.
KISS sin(x)/x compensation for non-oversampling DACs (2006, applies to 44.1 kHz sources)
Probably the most elegant yet satisfyingly correct way to compensate for sinc roll-off. It may help to achieve a proper tonal balance in some systems. However, I have given up on using such compensation circuits, both because they are always a sort of trade-off (frequency vs time domain), and because they must be designed specifically for a given Fs, which in today’s environments is not at all practical.
Asynchronous reclocker measurements (2005 and 2006)
Ryohei Kusunoki proposed this approach in his groundbreaking 1996/1997 articles in MJ Magazine, and I included it as an optional part of my early TDA1541A projects.
Today, we can probably easily solve the jitter causes way more consistently, in most environments. Nevertheless, the idea of rehashing and experimenting with jitter content and amount, and the possibility of completely breaking the connection between incoming and output jitter, without PLL or FIFO, was revealing.
Micro-Cap 6 files that plot bipolar transistor models’ Vce vs. Ic and hFE vs. Ic curves (2004)
Problem jittera u audiju (2006, in Serbian)
Struktura digitalnog PCM audija (2007, in Serbian)