Here you will find Audio Oriented projects, many in the German Language. There is one - Converting Analog into Digital (IIR) Filters which is useful for Mixed Design students. Then there is a FPGA-Based Digital Audio Peak Level and Correlation Meter with many features. The Hi-Fi Audiophile will like the Tools - Audio Preamplifier, Weighting Filter Set and Universal Filter.
DIY Electronics Section of Beis.de
DA2USB - Digital Audio to USB Interface
The DA2USB is a USB interface for connecting digital audio sources (S/PDIF or Toslink, with adapters also AES3) to a PC. It comes without proprietary drivers, i. e., there is no software to install and there is no threat that the hardware sometime will become obsolete waste because the manufacturer does not support it any more with up-to-date drivers (like my fine and expensive sound card did).
Other Interesting Projects here are
24 Bit / 192 kHz Audio ADC and DAC AD24QS and DA24QS
"It is very well known what kind of deviations from the original signal a human ear is able to hear (e.g. distortion, frequency response, noise etc.) and also in which amount and under which circumstances this is the case. All these deviations from the original signal are measurable with a precision and sensitivity far, far superior to the human ear...."
An Introduction to Delta Sigma Converters
Delta sigma converters are different from other converters. Note that I do not make a difference between analogue-to-digital (ADC) and digital-to-analogue converters (DAC). Both are very similar and what is realized in one of them using analogue signal processing circuitry is implemented in the other one using digital signal processing and vice versa. I will explain the delta sigma technique with the analogue-to-analogue delta sigma converter as the first object.