Audio Research

Last year we talked about the introduction of the first product in the new Foundation series, the LS28 preamplifier. Now Audio Research has completed the introduction of this series with three new offerings, the VT80 power amplifier at $8000, the DAC9 Digital-to-Analog Converter at $7500, and the PH9 phono preamplifier at $7500.

The VT80 is from the same design and engineering team responsible for the award-winning Reference Series. This new power amplifier combines an enticing new aesthetic with worry-free operation and great performance. It is a vacuum-tube amplifier that will make Audio Research accessible to a larger group of music lovers. With its beautiful new look, flexible connection options, and important new features, the primary goal of the VT80 is to provide an incredible musical experience. The core of the VT80 is adapted from the Reference 75, including the same power and output transformers, a similar circuit topology, and many of the same parts.

Two important new features never before offered by Audio Research are at the heart of the VT80. The first is a proprietary auto-bias circuit developed entirely in-house by Audio Research's chief analog engineer. Once the tubes are installed and the unit is powered-up, the VT80 will automatically adjust bias for each output tube. The circuit adjusts for tube wear or fluctuations in the power in real time and does not compromise performance. The VT80 will also work with different types of output tubes, including 6550, KT88, KT90, KT120 and KT150. The second new feature includes individual fusing of each output tube. In case of a fault condition, a replaceable fuse blows, providing worry-free operation.

The 75 watt-per-channel VT80 is a balanced design that provides startling dynamics, powerful bass, and natural clarity combined with a very holographic presentation. The open architecture of its extruded metal chassis provides beauty and a rigid structure from which two 6H30 driver tubes and four KT120 output tubes emerge. Available in both natural and black anodized finishes, the low profile front panel contains a black inlay that matches other Foundation Series products, along with a power switch, flanked by two handles.

The rear panel contains both single-ended RCA and balanced XLR input connectors that allow the VT80 to be integrated into virtually any system. In addition to a tube hour meter, there is also a switch to defeat the auto-off function which otherwise turns off the amplifier when no input signal is encountered for two hours.

The new DAC9 is a straightforward DAC with a vacuum-tube analog section and the latest digital design, capable of decoding DSD music files, upsampling to 384kHz, and the ability to accommodate multiple digital inputs. DAC9 design features include:

• Native DSD file decoding which converts DSD files to a true Direct-Stream-Digital signal running at 2.8224 MHz or 5.6448 MHz. DSD-to-PCM file conversion is not necessary.
• There are two distinct digital paths to the DAC9's D-A converters, one path for PCM music files from 44.1kHz to 384kHz sample rates and a separate path for serial DSD music files at 1x and 2x DSD clock rates.
• Quad D-A converters: Each channel uses dual stereo DACs running in mono to increase dynamic range and lower the noise floor.
• The DAC9 uses two different TCXO crystal Master oscillators, one for 44.1-88.2-176.4-352.8 kHz sampling rates, the other for 48-96-192-384 kHz sample rates. this assures proper integer decoding so there are no interpolation distortion errors that would degrade sonic purity. The proper time clock is selected automatically.
• Native sample rate upsampling is available for all inputs, up to 352.8kHz for 384kHz for non-DSD (PCM) music files.
• Selectable digital filters are available, with both Fast and Slow roll-off, so the user can customize according to personal taste.
• Four galvanically-isolated inputs include RCA, AES/EBU (XLR), BNC and Toslink to assure no ground loops.
• The zero-feedback, pure Class-A analog section features two high performance, long-life 6H30 vacuum tubes directly coupled to the D-A converters, with no capacitive coupling to diminish low-frequency response at this critical point.
• The DAC9 is fully balanced, with both XLR (balanced) and RCA (single-ended) analog outputs.
• 8 very low-noise, low-voltage regulators are used in the digital section, with a low-noise, high-voltage regulator for the vacuum-tube analog section.

The DAC9 is the most technologically advanced digital product ever developed by Audio Research and represents a sonic breakthrough in digital-to-analog music reproduction.

The PH9 is the latest in a long series of phono preamplifier designs from a company that never abandoned fine LP playback as one of its most important goals. With three high current 6H30 tubes, the PH9 provides higher transconductance, better dynamics, and better sound. With a new copper-wrapped R-core transformer and a larger, higher-current power supply, the sound is more powerful and dynamic, with deeper and tighter bass and greater musical authority. As in the Reference Phono 3, the PH9 also has vacuum-tube regulation in its power supply, using a 6550 and a 6H30. With a fixed gain of 58 dB, and loading options of 100, 200, 500, 1000 and 47k ohms, a very wide variety of phono cartridges can be accommodated. The single-ended RCA inputs and outputs assure compatibility with almost any system, and its low output impedance gives the PH9 the ability to drive long interconnects. All functions are readily available from the front panel or from the handy remote control, making the optimization of your cartridge's loading easy to hear from your listening chair. An hour meter, accessible from the remote, keeps you aware of just how many hours are on the tubes of your PH9, making regular maintenance a snap. The result of all of this technology is that the PH9 allows the beauty and naturalness of vinyl to shine.