For asymmetrical or quasi-symmetrical analog signal transmission between devices with RCA inputs and outputs. The very low-loss and low-capacitance HF coaxial cable is sheathed in a basalt braided sleeve, even inside the connector housings, ensuring crystal-clear signal transmission. When the C-C-C50-BA is connected between the RCA output of the Audio Optimum NOS-DAC and the analog quasi-symmetrical RCA input of the NOS-DAC 2 (NOS-DAC + preamplifier), there is no audible difference for cable lengths up to approximately 2 meters compared to the identical DA converter built into the NOS-DAC 2, which is internally connected to the analog preamplifier via circuit paths just a few centimeters long! No other RCA cable – even those shorter than 0.5 meters – has passed this ultimate test so far. Other cable lengths available upon request. Please contact us.

For the asymmetrical or quasi-symmetrical transmission of a digital SPDIF signal. Almost independent of the cable length, the basalt braided sleeve provides a noticeable improvement over bare 75Ω coaxial cable, as significant as with analog signal cables. By design, the signal edges of the SPDIF signal are flattened by the cable distance, causing jitter when – as is often the case – the receiving SPDIF-I2S converter has too large and undefined input hysteresis. The Audio Optimum NOS-DAC, which intentionally works without reclocking, treats the incoming SPDIF signal as an analog signal and restores the flattened signal edges precisely at zero crossing using a fast analog comparator. This avoids jitter, provided that the SPDIF source operates cleanly and the cable transmits the digital signal in such a way that the edge flattening remains relatively constant and symmetrical, regardless of the data stream. In this respect, the basalt braided sleeve appears to have an extremely positive effect. Connecting a good CD transport to the Audio Optimum NOS-DAC via the C-C-C75-BA cable can convince even die-hard analog vinyl enthusiasts of the quality of digital music reproduction. Other cable lengths available upon request. Please contact us.

For connecting devices or active speakers with a cold appliance plug of protection class I to the 230V power grid. A weakness of conventional power cabling systems is the use of Schuko plugs and sockets, which are not designed for shielding. Every Schuko socket is effectively a 44 mm diameter hole in the shielding, allowing high-frequency interference to enter. This issue is addressed with the Audio Optimum Direct Distributor, which directly and star-shaped connects up to eight shielded and ferrite-sheathed power cables. The connection is made via 24 Wago terminal blocks on two stacked circuit boards inside an RF-shielded aluminum die-cast housing. Beneath the distributor housing is a second housing of the same size containing the Audio Optimum-developed Power Cleaner. It consists of four copper plates insulated and mounted in defined distances on top of each other, with surfaces coated in black tourmaline. The two outer plates are connected to the protective ground, while the two inner plates are connected to neutral and phase, acting as X- and Y-capacitors with a lossy dielectric. Combined with the ferrite-coated input cable, which acts as a lossy inductor, an efficient second-order network filter is created. The ferrite suppresses high-frequency magnetic interference through remagnetization losses, while the tourmaline suppresses high-frequency electric interference through re-electrification losses. Unlike conventional power filters, HF noise is not reflected but converted into heat, making the Power Cleaner ideal for use before the distributor. The aluminum housings for the Direct Distributor and Power Cleaner, connected to the central grounding point, feature a stable tourmaline-polyurethane baked enamel coating on the surface, giving the overall construction the additional function of an effective ground box. Each outgoing cable has a two-stage special power filter integrated, extending the filtering effect of the ferrite sheathing to lower interference frequencies. The continuous HF attenuation spans from 300 kHz into the GHz range. The output cables are routed upwards, keeping the compact Direct Distributor space-efficient. In its combination of features, the Audio Optimum Direct Distributor is unique and guarantees the best possible sound quality for the connected system at any standard wall socket. The Direct Distributor is preassembled with three to eight output cables in the standard length of 1.6 m; for longer cable lengths, we offer custom quotes.

For the connection between power amplifier and multi-way speaker with passive crossover and bi-wiring terminal. Almost every passive multi-way speaker today has a bi-wiring terminal, though the practicality of this method is still debated. To test this at a high level, we chose a passive speaker originally not designed for bi-wiring: the Tannoy Cheviot, built in 1976. The 12-inch Dual Concentric drivers with Alnico magnets used at the time are still beyond reproach today. The internal wiring of the speaker cabinets was completely replaced with basalt-sheathed twisted pairs, and the signal paths for the high-frequency and low-frequency sections were separated on the original passive crossovers. A pair of SINCOS MonoAmps in full-range mode was alternately connected to the Cheviots using the 2-pole HS4-TP250-BA with bridged signal paths at the speakers or the 4-pole HS4-BTP250-BA with bridged signal paths at the MonoAmp terminals. Both cable pairs were 3.3 meters long. The clear result: the HS4-BTP250-BA is clearly superior, proving the positive effect of bi-wiring. While the sound difference is understandably not as pronounced as when the two Cheviots are driven by four SINCOS amplifiers via phase-parallel active crossovers, it is still clear enough to justify the extra effort for the 4-core special cable. The sound image appears tidier and clearer, and the spatial imaging is more precise. The HS4-BTP250-BA consists of two twisted pairs, each with a 2 x 2.5 mm² copper cross-section, where each pair is individually encased in basalt, and both pairs are enclosed by a larger basalt braided sleeve. This minimizes both mutual electromagnetic interference between the two wire pairs and external interference from high-frequency magnetic fields. Not only for modified Tannoy Cheviots but for all high-quality multi-way speakers with bi-wiring terminals, the HS4-BTP250-BA is perhaps the absolute best speaker cable available today, regardless of price! For amplifiers with one output per stereo channel, suitable adapters are included to connect the two wires directly at the binding posts. Other cable lengths available upon request. Please contact us.

For the connection between power amplifier and full-range speaker or multi-way speaker with passive crossover. It is now well-established knowledge that speaker cables, beyond their basic technical parameters (resistance, inductance, capacitance), have a significant impact on sound quality depending on both their mechanical design and the materials used. Why the new speaker cables from Audio Optimum enable a transmission quality that has rarely been achieved even with the most elaborate cables is not a "best-kept secret," but rather an honestly still unanswered question. However, we have the advantage that we can objectively hear our cables, and what is clearly audible and reproducible regardless of time and place cannot be dismissed as "voodoo," even if the differences are barely measurable and not yet fully explainable. The simplest version, the HS4-TP250-BA, consists of a twisted pair of copper cables (Twisted Pair), each with a 2.5 mm² conductor cross-section, which is encased in a braided basalt fiber sleeve. The cable ends are soldered with gold-plated 4mm hollow plugs, ensuring the lowest impedance and most secure electrical connection in all standard binding posts or 4mm sockets. With a certain amount of iron oxide, the basalt effectively shields against high-frequency magnetic interference without damping high-frequency reproduction in the audible audio range. The sound is incredibly precise, open, and neutral; the improvement in sound quality is noticeable with any high-quality amplifier-speaker combination. Other cable lengths available upon request. Please contact us.

For the connection between power amplifier and 3-way speaker with passive crossover and tri-wiring terminal. The HS4-TTP250-BA consists of three twisted pairs, each with a 2 x 2.5 mm² copper cross-section, where each pair is individually encased in basalt, and all three pairs are enclosed by a larger basalt braided sleeve. This minimizes both mutual electromagnetic interference between the three wire pairs and external interference from high-frequency magnetic fields. For all high-quality multi-way speakers with tri-wiring terminals, the HS4-TTP250-BA is currently perhaps the absolute best speaker cable available, regardless of price! For amplifiers with one output per stereo channel, suitable adapters are included to connect the three wires directly at the binding posts. Other cable lengths available upon request. Please contact us.

For connecting devices or active speakers with IEC connectors of protection class I to the 230V power grid. Power cables can have a greater impact on sound quality than, for example, signal cables. The power cables themselves do not have a sound character, but they differ in how they suppress and shield high-frequency interference, which the devices cannot protect themselves from. Conventional power filters, as built into most devices, suppress frequencies up to about 50 MHz. However, it is precisely the higher interference frequencies (mobile networks: 900 MHz to 2.6 GHz) where devices are particularly sensitive, and these can only be effectively suppressed with a ferrite filter section. In addition to a continuous ferrite coating on the phase, neutral, and ground conductors, the SK-GK-NFE-BW features a foil shield and an outer covering made of pure cotton, which, by absorbing natural humidity, dissipates static charges and high-frequency leakage currents from the surface of the cable jacket. The foil shield is galvanically grounded at the Schuko plug and capacitively grounded at the IEC connector, ensuring that the shielding is connected on both sides at high frequencies and on only one side at low frequencies, preventing equalization or leakage currents from flowing through the shielding foil. Only the combination of all these characteristics guarantees interference-free operation of the connected device; other features (oversized copper cross-section, gold-plated plugs, etc.) are comparatively insignificant or even harmful (e.g., plastic mesh covering) to the resulting sound quality. Since the ferrite coatings make the cable conductors thicker and less flexible, a copper cross-section of 3 x 1 mm² was deliberately chosen, which is sufficient for a continuous power output of up to 2.3 kW. A larger copper cross-section is oversized for hi-fi devices and impractical to handle. In combination with our 4-way, 6-way, or 8-way power strip with star-wired internal cabling, the SK-GK-NFE-BW forms perfect power cabling systems for high-end systems and studio equipment that work without limitation at any standard wall socket.

For connecting devices or active speakers with IEC connectors of protection class I to the 230V power grid.The SK-GK-NFE-FI-BW shares all the essential characteristics of the reference power cable SK-GK-NFE-BW and additionally features an integrated special power filter that extends RF suppression to lower interference frequencies. The continuous ferrite coating of the power cable achieves its full damping effect above 100 MHz. For the interference frequency range below, the integrated special power filter takes over, resulting in continuous RF suppression from 300 kHz up to the GHz range. Unlike conventional power filters, the two-stage special power filter is a 4-wire system, where protective earth and shielding are conducted separately. Moreover, it is effective in a frequency range approximately ten times higher (300 kHz to over 200 MHz) than conventional power filters (30 kHz to about 30 MHz), ensuring no oscillation tendency in conjunction with a power filter already built into the connected device. The SK-GK-NFE-FI-BW is also designed for a maximum current of 10 amperes, making it universally applicable for both analog and digital source devices, as well as for power amplifiers or active speakers.In combination with our 4-way, 6-way, or 8-way power strip with star-wired internal cabling, the SK-GK-NFE-FI-BW forms perfect power cabling systems for high-end systems and studio equipment that work without limitation at any standard wall socket.

For symmetrical transmission of a digital SPDIF signal (AES/EBU). Especially for longer distances between the CD transport and the DAC, the XF-XM-TP34-BA is advantageous, but even for shorter distances, symmetrical transmission should always be preferred, provided both devices offer this connection option. Other cable lengths available upon request. Please contact us.

For symmetrical analog signal transmission from the preamplifier to the active speakers or to separate power amplifiers. Compared to the XF-XM-TP56-BW, the XF-XM-TP75-BA offers even more bass control, enhanced musical detail resolution, and extraordinary spatiality. The low-loss base cable with a large conductor cross-section and low capacitance delivers an extremely high-resolution yet slightly hectic sound image without the basalt sheath. With the fine basalt fiber braided sleeve, the sound becomes absolutely authoritative and holistic. It gives the impression that the preamplifier has complete control over the active speakers, while the finest musical details become audible. The presentation of spatial reproduction is unique. Other cable lengths available upon request. Please contact us.