adda191 is a modularly configurable converter system in 19″/1U format, technologically based on the well-known arfi-adc2pro and arfi-dac2pro converters. The proven technology is complemented by a completely new power supply and the further optimised clock section, which can generate the high-precision reference clock from an externally supplied word clock as well.

The standard configuration of the adda191 is the ADDA converter, a 2-channel AD converter plus a 2-channel DA converter. Alternatively, partial configurations as a pure AD-converter or a pure DA-converter are possible.

On the analog side, the signal paths are slender and straightforward – following the audiophile sense – and are realised with the best components. The analog signal routing and processing are completely balanced. The AD-converter uses our unique purely passive analog input stage. There are only two high-quality input transformers between the analog inputs and the AD-converter chip, thus, no amplifier stages in the signal path before the actual converter. The DA converter is a built-in “arfi-DAC” topology, which means that a total of four DAC outputs generate the stereo signal in a sophisticated way via transformers in the I/V stage. An upgrade to “arfi-reference-DAC” topology is also available, and we also offer various options for the interfaces.

Our Femto-Clock II is used in the clock section. This module also provides the clock distribution to the converter boards, thus ensuring shortest paths and highest precision. External sources via AES or Wordclock thus achieve a precision that could otherwise only be achieved by using the internal clocks.

Out of sonic conviction we have made some design decisions in our converters that deviate from the mainstream. As with all our previous devices, DSD is deliberately not supported (see the article on our website “Getting the sampling theorem right!”) and there are no other user-accessible gimmicks such as integrated up-sampling, switchable digital filters or the like.

The only exception is a unique analog filter that can be activated on the DA converter and helps to compensate for deficits in recordings with standard sampling rates (44.1kHz and 48kHz).

All this together is the key to music in accordance with ACOUSENCE: natural sound, artistically rousing and emotionally moving music playback!