The DUO is derived from the cost-no-object PhonoBlock and the cost-optimized 20/20. 

No expense was spared in the design and construction of the Phono Blocks. The Phono Blocks are at the pinnacle of phono preamp performance. It just doesn’t get any better. 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 PhonoBlock. The actual signal path of the 20/20 is quite good. It uses a circuit very similar to the PhonoBlock. 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. Enter the DUO...

Each 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.

Features

• FR-4 fiberglass circuit boards
• Double-sided with plated thru holes
• 1/8” thick for extra rigidity and minimal dielectric influence
• Dale/Vishay 1 % metal film resistors
• Wima Polypropylene capacitors for power supply by passing and DC servo
• Custom wound, 1 % polystyrene film capacitors for equalization
• 14 gauge cold rolled steel base baked epoxy powder coat finish
• 1/2 “ thick anodized aluminum panel
• Anodized in front panel artwork
• Gold plated, Teflon insulated RCA connectors
• Gold plated configuration headers and shunts

Linear Power Supply Upgrade: Factory upgrade. Linear Power Supply reduces noise by transforming line voltage.