With the adda191 reference, music transmission is taken to the extreme according to the ACOUSENCE philosophy. As with adda191, the focus is on natural sound and artistically rousing, emotionally moving music playback. Music should be converted back and forth between the analog and digital worlds as unaltered as possible.

However, the DA converter in the adda191 reference is now built in “arfi-reference-DAC” topology, which means that a total of eight DAC outputs generate the stereo signal in a sophisticated way via premium transformers in the I/V stage. This provides an even more refined resolution of the smallest nuances while maintaining a very coherent music reproduction. An external controller for the internally realised volume control is optionally available. This makes the DAC the ideal solution for high-end monitoring.

Compared to adda191, the AD-converter now comes with a whole range of functional extensions. This gives the user a wide range of sonic possibilities; basically, an entire colour box for creative producers: With the “passive” button, the adda191 reference can be set to the classic mode of the adda191 and its predecessors, where only our special purely passive analog input stage is used. Otherwise, however, the active amplifier stage is additionally looped in. The level of line signals can now be adjusted in eight 2dB steps (maximum 14dB additional gain). A completely new feature is the possibility to process microphone signals (eight 6dB steps and 72dB max.). In addition, the transmission ratio of the input transformers can be switched. The resulting level difference of 6dB can be compensated by the active stage, if necessary.  Thus, there are three different ways of processing the same signal level for line level and two for microphone signals. Each combination has its own discreet signature, which can be used creatively while maintaining our technical and tonal philosophy.

Otherwise, the adda191 reference, like the adda191, is a 19″/1U converter system, technologically based on the well-known arfi-adc2pro and arfi-dac2pro converters. The proven technology is complemented by the further optimised clock section, the Femto-Clock II, which is now also extended by the possibility of generating the high-precision reference clock from an externally supplied Wordclock. External sources via AES or Wordclock thus achieve a precision that could otherwise only be achieved using the internal clocks. This module also takes care of the clock distribution to the converter boards, thus ensuring shortest paths and highest precision.

On the analog side, the signal paths are slim and straight  – following the audiophile sense – and are realised with the best components. The analog signal routing and processing is completely balanced. The volume control, which can be used via an optional controller, is done in the best possible way via switched fixed resistors. With this controller, other important functions for monitoring can also be remotely controlled.

Different connection formats can be selected for the two digital inputs and the digital output. The standard is AES/EBU on XLR. However, AES/EBU on RJ45 and SPDIF on BNC/Cinch are also possible. An optic fibre module for bidirectional connection rounds off the optionally available range. This allows the ADDA to be connected to a computer without any interference from the sound-critical IT world on the sensitive analog signals (using a Toslink interface; not included in delivery).