arfi-dac2 - artistic fidelity da-converter
24/192 digital-analog converter
Our first DA converter is now available. We have consciously added this development in our chronology after the afis, USB module and AD converter. The concepts introduced by the afis and USB module are necessary starting points for convincing music playback. During the development phase, the arfi-adc2 was an important "tool". Because only when the AD conversion succeeds as well as possible can the original analog signal be the valuation standard for the DA converter.
With our arfi-dac2 you can hear our many years of experience in music production and thus the sound concept of real instruments and ensembles. Comparisons to the best analog technology and vinyl records have always important to us. So basically, the result is an arfi-adc2 "in reverse". Here we also see the precisely contoured image of transients along with tonal purity and a full, round basic sound. Fine musical details, atmosphere and emotions have seldom been so audible, but the important this is: listening to music is simply an unbelievable pleasure.
The arfi-dac2 adheres to the concepts behind the afis, afi and USB module - this means: interfaces, HF interference and clocking. Therefore, we consciously go our own way, analogous to the arfi-adc2: consistently sticking to the basics. The arfi-dac2 itself has only one single input; however, since it is RJ45 Ethercon, it is a technically perfect connector and thus harmonises well with our other components. If several sources are desired, then an afis can be used additionally as a main switch. The USB connection is integrated here as well. If a USB connection is enough, then an afi+USB can also be directly connected via RJ45-Ethercon. The great afip power supply unit completes this trio and feeds both devices.
A special feature to be mentioned is the master clock input in the same format as the arfi-adc2 masterclock output. This input can be switched to use this as a clocking source. Thus the internal PLL (clock recovery from the digital signal) is avoided and PLL no longer plays a role. The DA converter directly follows the master clock of the oscillator unit in the arfi-adc2.
On the analog side, you again find, fully in the interest of audiophiles, short and simple signal paths; these are again highly sophisticated and equipped with the best components. There are several design detail decisions that differ from the mainstream. We consciously do not use DSD in the arfi-adc2 (see article "Apply the sampling theorem correctly!"). Also, we do not use user-friendly gimmicks via microcontroller and FPGA like integrated upsampling, switchable filters or the like. Computers are establishing themselves anyway as the ideal way to listen to music, and there is surely hardly a better source than the afi(s) + USB to make it possible. And this is why every form of digital signal processing should take place in the computer. Here, the highest precision with 64-Bit floating comma is possible and HF-generating calculation processes take place far away from the analog electronics and from digital sections disruptive to clocking, shielded in the best possible way. Also, music that is only available in DSD can be perfectly converted on the computer to 176.4 kHz PCM and thus as a rule this delivers better results than with a native playback with a conventional DA converter connected via USB. The moving coil indicator, which displays the sampling rate, also serves to bypass the microcontrollers. Here, we also try to concentrate on our core task - digital to analog conversion - omitting unnecessary dead freight.
Another central characteristic is the total forgoing of any type of active amplification between converter chip and analog output; no transistor, no operation amplifier and no tubes. Instead, eight converter outputs, interconnected with each other in a highly sophisticated way via two high-quality transformers to create an analog stereo signal. In our view, this is the key to music in terms of "artistic fidelity": natural sound, artistically compelling and emotionally moving music playback!