Sutherland 20/20 Mk2
The Sutherland Engineering 20/20 was created with a vision to achieve an extremely low noise floor and precise resolution. It is derived from the best elements of the previous models, the PH3D and the Hubble. It has an elegant aesthetic of performance, value, craftsmanship and minimalism. That heritage, however, does not keep the 20/20 design from taking on its own unique character.
Everyone wants the advantages of AC power line isolation offered by battery operation. The 20/20 is for the person who wants those advantages but does not want to mess around with batteries. The 20/20 comes as close as possible to offering an equivalence of battery isolation from AC line power. It is AC powered and super quiet!
The 20/20 is a one box solution with literally two identical mono RIAA phono preamplifiers within. Each channel is on its own circuit board, has its own shielded compartment, power indicator, its own AC power supply and its own power cord. It is the ultimate in channel separation.
The resulting sonic performance is superb, with a very natural, smooth articulate sound.
In the quest for the ultimate in stereo separation, the 20/20 goes beyond dual mono, offering instead what Ron Sutherland likes to call “two-mono.” Many audiophiles prefer using mono-block amplification for the benefits of eliminating crosstalk and other noise contaminants associated with shared power supplies. They also prefer the benefit of each amp having its own reservoir of power, increasing dynamic capabilities, and giving the amp a sense of ease. This is exacerbated in a phono-preamplifier environment where noise is the worst of enemies. The 20/20 may look like a conventional stereo phono stage but if you take off the cover you will discover two identical mono phono circuit boards, sharing only the same front and back panels. Power supplies, power cords , and all circuitry are separate. Even the power indicator lights are independent.
The 20/20 uses two regulated tabletop power supplies (one for each channel) to taps mounted toward the front of the dual mono circuit boards. These are SMPS units and the cables are “figure 8” with DC plug terminations like used on portable laptops. Only DC is present on these cables so the RF is not near any electronics. You plug these in on each chassis underneath then install the chassis in the rack. The wires are then groomed out the back to the wall or to the power strip of your choice. To understand why Sutherland have designed the power supply system in this way, let’s look at AC to DC power supply elements required for no-compromise high-end performance:
- Rectify the AC to DC
- Filter that DC
- Use that raw DC to power a regulating DC to DC switching inverter (this stage also provides galvanic isolation between the AC power line and the DC load)
- Provide additional levels of filtering to remove the high-frequency ripple from the switching inverter.
- Provide additional levels of noise isolation from the switching inverter to the load
- Provide local voltage regulation right at the audio circuitry.
From an engineering viewpoint, items 1, 2 and 3 can be accomplished with a well chosen, off-the-shelf table top power supply. It does those tasks well, reliably and at a very reasonable cost. The supplies included with the 20/20 are rated at a MTF (Mean Time between Failure) of over 100,000 hours. They are used at less than 10% of their rated capacity, so reliably should be even further increased. If one were to fail, replacement is simple and inexpensive. In addition to that functionality, they are already safety tested and approved for use all over the world. A great deal more time, effort and money could be spent on custom circuitry – but to no performance advantage.
From an audiophile viewpoint, it is items 4, 5 and 6 that determine the quality of DC available for the sensitive audio circuitry. That function is so important it takes up over 2/3 of each amplifier’s circuit board area. Ten cascaded stages of passive RC filtering provide an enormous distance from the preamp area to the incoming DC power connector. There are over 35,000 microfarads of capacitance on each board. The electrical ‘distance’ is so great, when power is first applied, it takes over 10 seconds for the power to travel through these ten sections of filtering and reach the preamp stage. Voltage slowly ramps up until the zener diodes clamp it to the correct value. Until that voltage is reached, the audio output is muted. It is this section of circuitry that provides the extreme isolation from AC power line affects.
DC Connector Location
There are no power connections on the back panel. Instead, you will find them located at the front and under the cover. That is one of those form follows function design decisions. The front of the circuit board is where the power enters the circuit, therefore that is where the connector is located. On your car, the gas cap is very near the gas tank. It is not located at the opposite end of the car.
Putting the entry point at the front permits power supply wires (low voltage DC) to be routed well away from all the sensitive part of the circuit. Contrast that with the AC IEC power connector (high voltage AC) conventionally located on the back panel very near the preamp circuitry and all the input/output jacks.
Beautiful on the Inside
It is the internal design and execution of the phono preamplifier which is responsible for its contribution to the sound. For those clients who are knowledgeable about electronic design, note that the 20/20 has FR-4 fiberglass circuit boards (double-sided with plated thru holes), Dale/Vishay 1% metal film resistors, Wima Polypropylene capacitors for power supply application by-passing custom-wound 1% polystyrene film capacitors for equalization. The chassis is 14-gauge cold rolled steel with a baked epoxy powder coat finish. The 1/2“ thick anodized aluminium front panel features anodized artwork and the RCA connectors are gold plated & Teflon insulated. The configuration headers are also gold plated.
This intelligent architecture, attention to detail and craftsmanship results in a phono amplifier that sounds wonderful and gives you confidence that it will continue emotionally connecting you to your analogue music for many years to come.
- Plentiful loading and gain options for both MM and MC cartridges
- Compact, discreet chassis is impressively well-built and solid
- Quiet, dynamic, and musical beyond its price
Sutherland 20/20 Phono Preamplifier: Two-Mono Analog
Ron Sutherland Talks About the Sutherland 20/20 Phono Preamp
Sutherland 20/20 Phonostage Review w/ Upscale Audio’s Kevin Deal
|Gain Settings||40, 46, 52, 58 or 64dB|
|Loading||100, 200, 425, 1k or 47k Ohms|
|Power Requirements||20 watts (10 watts per channel)|
|Operating Voltage||100 to 240 volts (universal, no adjustments)|
|Power Supply||2 x External Regulated Tabletop Power Supplies|
|Dimensions||432mm (wide) x 305mm (deep) x 57mm (high)|
|Shipping Weight||8.6 kg|