I have to admit that I was quite disappointed when I took a look at the back of the R-580. The fact that there is only one stereo input can, in my opinion, easily be forgiven. But the circumstance that the R-580 only connects to the tonearm cable via two RCA jacks doesn't make sense to me. After all, the generator of a cartridge is a free-of-ground, balanced signal source. Michael Børresen of course knows that, too, and that's why the RCA jacks conceal a discreetely designed, floating, balanced input circuit, which operates with ultra-low noise bipolar transistors. By connecting several pairs of transistors in parallel, an extremely low-noise input section was thus created: The signal-to-noise ratio is said to be 94 decibels at one kilohertz. Considering the balanced signal routing via RCA, the shielding of the tonearm cable and the ground wire of the tonearm should ideally be connected to the phono stage via the grounding cable alone. Therefore I asked Morton Thyrrestrup to include a suitable tonearm cable in the shipment right away, as cables are readily available in the group of companies, which also comprises Ansuz. He recommended a Signalz Interconnect Tonearm D-TC2, which takes up the number two in the product hierarchy, offering connections for a PowerBox, but which remained unused here.

As expected from a component developed by Michael Børresen - I was already given the opportunity to familiarize myself with the Ansuz PowerSwitch and the Børresen 01 Silver Supreme -, there are also innovative and exciting solutions to be found in the R-580, some of which he specified to me in a telephone conversation: In the input stages of phono preamplifiers commonly MOSFETs are used, while he uses in his circuitry however bipolar transistors and namely BISS types. The acronym stands for "Breakthrough In Small Signal". The noise level of these transistors approximately equals that of a two-ohm resistor, being therefore extremely low. The disadvantage of such a circuit design is evident in the cartridge having to be protected from voltage feed from the amplifier by a capacitor. In a floating, balanced circuit using BISS transistors, however, one could do without the capacitors. Therefore, in the Aavik phono preamps arrays of BISS transistors selected in pairs form these floating, balanced input stages. To the best of his knowledge, no other circuitry can achieve such a good signal-to-noise ratio, Michael Børresen explains.

Eleven Ansuz dither circuits are used in the R-580, whose very low-frequency voltage ratings around seven to eight hertz modulate the DC voltage provenient from the resonant-mode switching power supply. The modulation voltage ranges about 140 decibels below the DC voltage. Still, they keep the voltage regulators "busy", so that they are able to step in more effectively in smoothing the ripple on the DC voltage. Since I couldn't spot any relay on the circuit board, I asked Michael Børresen how the various load impedances are to be set on the R-580: He refuses to use mechanical switches or relays, because the fine detail information carried in the fragile phono signal would get lost. He relies on photoresistors or LDR sensors instead. A light source is controlled via the menu, the intensity of which would then realize the selected resistor value in the LDR: a completely contact-free solution that is also common in studio compressors in a similar form. The developer also revealed that the equalization is performed partly active, partly passive and that the R-580 gets by with only two voltage gain stages. Apart from the significantly higher number of elements used for suppressing RF interference and noise from the mains, the R-580 also differs from the R-180 and R-280 by even higher quality and more strictly selected components.