Sutherland DUO Phono Preamplifier
No expense was spared in the design and construction of the DUO Phono Blocks.
The DUO is derived from the cost-optimized 20/20. The DUO Phono Blocks are at the pinnacle of phono preamp performance. It just doesn’t get any better.
The penultimate in the Sutherland line, the 20/20 was designed to get the most performance possible at its predetermined price point. To get there, extra was spent to get premium parts and circuitry into the signal path. Consequently, some expenses were squeezed out of less important areas. Those trade-offs have worked very well. The 20/20 has delivered an extremely high level of performance at a reasonable price. It is an incredible performance value.
What if all the price constraints in the 20/20 were lifted? The price goes up; the performance goes up. It starts looking a lot like the DUO Phono Blocks.
The actual signal path of the 20/20 is quite good. It uses a circuit very similar to the DUO Phono Blocks. In critical positions, it also uses the same premium quality (and high cost) components. Very little was held back in that area.
The opportunity for upgrade is focused on a more refined power supply, improved circuit board properties and dual chassis construction.
Each Sutherland DUO has a built in AC power supply.
There is an IEC power inlet on each chassis to accommodate the user’s personal power cord choice.
The shielded power supply module has one output. That output is split into two branches. One for each of the two gain stages. Each of those branches is independently filtered and regulated to provide a substantial foundation for the gain stages.
The 20/20 uses external, bench-top power supplies. They are cost effective, reliable and offer good performance. Each supply’s output is extensively filtered and regulated into one +/- 15 volt source for both of the gain stages.
Sutherland DUO GAIN ADJUSTMENTS
Each channel has two configuration headers: One to select cartridge loading and an-other to select gain. When changing configuration, be sure to set each channel to the same value. Options are printed directly on the circuit board next to the configuration headers.
There are five available gain settings.
- 40 dB
- 46 dB
- 52 dB
- 58 dB (factory setting)
- 64 dB
Gain is set using the supplied, gold-plated shunts. There is a gain setting header block for each unit. Position the shunt to the desired gain value. Be sure to set the gain of each unit to the same value.
Sutherland DUO LOADING ADJUSTMENTS
Each channel has two configuration headers: One to select cartridge loading and an-other to select gain. Options are printed directly on the circuit board next to the configuration headers.
There are five available loading settings.
- 100 Ohms
- 200 Ohms
- 475 Ohms
- 1k Ohms
- 47k Ohms
Loading is set using the supplied, gold-plated shunts. There is a load setting header block for each unit. Position the shunt to the desired gain value. Be sure to set the loading of each unit to the same value.
Sutherland DUO SPECIFICATIONS
A DUO consists of two matching units. The dimensions below are indicated PER UNIT.
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GAIN SETTINGS:
Gain is determined by the resistor value installed in the GAIN resistor socket.
Dale/Vishay RN65-style resistors are included with the following values.
- 40 dB gain
- 46 dB gain
- 52 dB gain
- 58 dB gain (factory setting)
- 64 dB gain
LOAD SETTINGS:
Cartridge loading is determined by the resistor value installed in the LOADING resistor socket.
Dale/Vishay RN65-style resistors are included with the following values:
- 100 Ohms
- 200 Ohms (factory setting)
- 475 Ohms
- 1k Ohms
- 47k Ohms
SIZE:
- 17” wide
- 12” deep
- 2 1/2″ high
WEIGHT
- 11 lbs.