Signature Rendu SEoptical build details, and comparison to opticalRendu+Sonore Power Supply

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The question is often asked, why does the Signature Rendu SEoptical cost what it does, and how does it differ from the opticalRendu + Sonore Power Supply. In this post I will describe the differences, and also point out some of the build details of the Signature level Rendu.

The Signature Rendu SEoptical (here forward SRsO) is custom built to order, one at a time, from start to finish, here at the Ice Station Zebra workshop. Each unit is then fully tested, playing back music for a minimum of 3 hours before boxing and shipping to the customer.

Differences between the SRsO and the opticalRendu/Sonore Power Supply:

1. Including the power supply and processing in a single chassis allows for closer coupling (no cable distance and connector losses) of the power supply. This close coupling reduces impedance between the power supply and the main board, allowing for a faster response of the power supply to transient current demands. In digital circuits like this, the response to transient current demands is critical to performance.

2. The SRsO features a beautiful, custom, made in the USA chassis of heavy gauge aluminum and steel (steel bottom and rear panels, Aluminum top, front, and side panels). This construction creates a solid, vibration resistant environment allowing the circuitry to perform its best free from degradation caused by external influences. Internally, there is a shield of a very carefully chosen alloy, between the AC input side and transformer, and the power supply and main board side of the chassis; this shield isolates the power supply and main board from any airborne AC line noise, and transformer's magnetic field (EMI).

3. The SRsO uses a custom, made in the USA, transformer developed in cooperation with, and manufactured by Mercury Magnetics. This transformer uses an EI style design, which rejects much more AC line noise than the standard toroid style transformer used in the Sonore Power Supply. BTW, the cost of the transformer is nearly 10x that of the one used in the Sonore Power Supply.

4. The SRsO uses super high quality, Mundorf electrolytic capacitors for the main power supply filter. It also has nearly 3 times the total capacitance in the power supply, resulting in further reduction of power supply noise.

5. The SRsO has additional filtering on the AC input, not present in the Sonore Power Supply, and has other parts upgrades in critical spots.

General build notes on the SRsO:

As many connections as are practical are made by direct soldering, as opposed to the push-on connectors found in so many audio products. Direct soldering creates an airtight, oxygen free connection of the lowest possible resistance, which will not degrade over time. In the two connections which cannot reasonably be done by direct soldering, carefully chosen screw terminals (with no steel parts, made of copper alloy) are used, which can be re-tightened if ever necessary. For these two terminal connections, the wire ends are treated with DeOxit during the build to guard against long term oxidation and improve conductivity.
In the US voltage units, the transformer primary wiring from the IEC connector is twisted into a star quad configuration which is a self shielding geometry which resits both external noise pickup, and airborne noise broadcast. 230 volt units only have two transformer primary wires, so those units use a twisted pair. All transformer secondary wires to the power supply board are also in a twisted pair configuration. Internal wiring from the power supply board to the main board uses very high quality, heavy gauge, silver plated copper wire, in FEP (AKA Teflon) insulation. As much hardware as is possible is stainless steel for long term, corrosion free performance.