Atlas Mavros Ultra 2 RCA to 2 RCA 1.5m Grun
RCA interconnect cable based on the same design objectives and manufacturing techniques developed for Atlas’ Asimi range, utilising copper rather than silver conductors. The new generation Mavros now features the Grun Coherent Earthing System.
The Mavros Ultra RCA uses the very highest quality ‘6N’ (99.99997% purity) copper manufactured using the OCC ‘Ohno Continuous Cast’ technique. Cables manufactured with lower grade materials and poor manufacture typically have a coarse, grainy structure which compromises sound quality. In the manufacture of Mavros, Atlas maximise the copper’s conductivity by ensuring that there is typically one grain in approximately 125 metres of conductor, allowing the signal a continuous unbroken path –in practice, the signal has a faster, cleaner and more direct path to follow.
The cable consists of a pair of conductors, each made up from six bundles of 12 multi-conductor wires, plus a thicker centre wire. This in turn is covered by a continuous copper/Mylar™ electrostatic screen with copper shielding braid, ensuring minimal susceptibility to RF interference and noise.
Theoretically, the best dielectric (insulation layer) is air. Conventional dielectric (insulation) materials impose their own signature distortion and loss on the signal. Atlas’ technique uses a microporous PTFE (Teflon™) tape, which is wound around the core conductors, then covered again and stabilised using a protective FPE (Flexible PolyEthylene) dielectric. This process maintains the required conductor geometry, and bestows greater manufacturing consistency. Termination is with Atlas’ low mass, high bandwidth, cold-weld Ultra RCA or XLR connectors, both of which have minimal effect on the integrity of the signal.
- Ultra RCA Plugs
- OCC Copper Conductors
- PTFE Dielectric
- Twin Multi-Core Construction
- Dual Drain (‘DD’) Technology
- Grun Coherent Earthing System
- Supplied with 1x Grun Achromatic RCA Adaptor to 2 Female Connectors
Ultra RCA Plug
The Ultra is a wide-band, OCC copper, constant impedance, self-cleaning, solder-free construction RCA plug.
In Atlas’ cables, the conductor to plug interfaces are solder free, and the gold-plated conjugate brackets act as the return signal path, helping to reject RFI. Both conjugate brackets (these grip the cable without the adverse effects of compressing it, which can alter impedance) have two asymmetrical leaves which spring open on insertion and wipe clean the signal path. To maintain a clean signal path, simply remove and re-insert them periodically.
The Ultra RCA connectors utilise low-mass non-magnetic connectors to minimise the negative effect of excessive metal in the plug itself.
Ohno Continuous Casting Copper (OCC Copper)
The Ohno continuous casting method re-heats the extrusion as the molten copper is forced out of the mould and very slowly and gradually draws the grain or crystal down the conductor”s length, creating a ‘single crystal structure.’ Actually, because no copper is 100% pure, there will always be a few boundaries produced by impurities. The frequency of boundaries created are quite insignificant. A typical crystal in a copper conductor drawn to 0.3 mm diam. using the OCC process is 125.00 metres long!
The benefits are obvious, with almost no crystal boundaries, the audio signal is no longer impeded down the copper wire and more information and detail is delivered faithfully to the receiving equipment.
|Copper Purity Comparison (0.3mm Diameter)|
|Gas Impurities (ppm)|
|Average Crystal Size (Metre)||0.007||0.02||125.00|
|Crystals Per Metre||150||50||0.008|
PVC (Poly Vinyl Chloride) is cheap to produce and, as such, is the most commonly used insulation in AV cables. However, PVC is the worst quality insulation a Hi-Fi or AV signal can encounter as its high loss causes a significant reduction in signal velocity. PVC is better suited to power cables and should be avoided in Hi-Fi and AV signal cables.
Other dielectrics in common use are Polyethylene, Polypropylene and Polytetrafluoride Epoxy (better known as PTFE (Teflon™) or Teflon,) and the new and unique Atlas (PTFE).
Microporous PTFE (Teflon™) is a unique, low density dielectric material, phase stable at room temperature, which offers significant performance improvements over solid PTFE (Teflon™) dielectric designs.
The table below shows the properties of a selection of dielectrics. Though not used as a dielectric in Atlas’ cables, PVC is included for comparison purposes.
|Dielectric Material Comparison (0.3mm Diameter)|
(FEP or PTFE)
(@ 50 -106Hz)
(% @ 50 – 106Hz)
(Ohms.cm @ 20°C)
|Max. Continuous Operating Temp.
|Min. Operating Temp.
|-15 to -40||<-60||-5 to -45||<-60||-250|
Twin Multi-Core Construction
A pair of identically matched conductors (one for signal path, the other acts as the return conductor) enclosed within a non-conducting screen. Combined with Atlas’ DD (dual drain) system which avoids distortion of the screening braid during assembly – this can change the impedance and therefore the performance of the cable.
Atlas DD (Dual Drain) System
Normally screened cables suffer from screen distortion when they are prepared for production. (If you’ve ever wired a plug or connector which uses a screened cable, you’ve done this yourself, cutting back and probably twisting the screening braid for termination). This distortion of the screen has a measurable impact, effectively changing the impedance and therefore the performance of the cable.
Twin symmetrical drain wires (each attached to 180° segments of the plug) are inserted between a 100% copper/Mylar™ foil and screen. The unique dd system connects the screen effectively to the cable return/plug interface, meaning the cable can be terminated without distorting, twisting or mechanically stressing the precision-laid screen. The benefits are in maintaining a consistent low impedance load to the plug, and a total 360° screening against noise and signal loss caused by RFI (Radio Frequency Interference).
Grun Coherent Earthing System
One of the biggest obstacles to achieving the performance levels equipment is capable of is noise. Low levels of RFI (radio frequency) and EMI (electro-magnetic interference) and noise on the signal ground all subtly modulate and degrade the overall noise levels of the system.
Ironically, this is generally only noticeable when eliminated – even though much of this ‘noise’ is theoretically at frequencies beyond the range of our hearing. The main sources are noise in the mains supply and component ground connections – mobile phones, ‘wallwart’ chargers and wifi networks are major offenders – while a percentage is actually generated within the equipment itself. Generally things have got worse with the advent of computer audio.
The Grun Coherent Earthing System addresses these issues by providing an ‘independent’ earth for users of Mavros and Asimi Ultra interconnects with the new Grun configuration.