BAT - VK-85 Preamplifier
BAT - VK-85 Preamplifier
Introduced simultaneously with the REX 300 power amplifier, the Balanced Audio Technology VK-85 preamplifier blurs the lines between the finest tube and solid-state sound. VK-85 features BAT’s trademark high-current Unistage topology with transformer-coupled outputs that anchor the full line of Balanced Audio Technology’s preamplifiers. VK-85’s second-generation output transformers work in conjunction with a symmetrical N-channel Unistage gain block to provide the high-current operation that is a BAT hallmark. A revised connection scheme for the SuperPak Quattro technology used in REX 300 offers beguiling levels of musical finesse and textural beauty. More
Product code: PRD00245 Shipping and Payment
Introduced simultaneously with the REX 300 power amplifier, the Balanced Audio Technology VK-85 preamplifier blurs the lines between the finest tube and solid-state sound. VK-85 features BAT’s trademark high-current Unistage topology with transformer-coupled outputs that anchor the full line of Balanced Audio Technology’s preamplifiers. VK-85’s second-generation output transformers work in conjunction with a symmetrical N-channel Unistage gain block to provide the high-current operation that is a BAT hallmark. A revised connection scheme for the SuperPak Quattro technology used in REX 300 offers beguiling levels of musical finesse and textural beauty. More
Product code: PRD00245 Shipping and Payment
SuperPak Quattro
The revised power supply of VK-85 incorporates the same fourth-generation SuperPak used in REX 300. In addition to providing four levels of filtration, it is connected in a new manner that dramatically lowers the preamplifier’s overall noise floor. The parts used in SuperPak Quattro include premium silver foil/oil capacitors that improve harmonic accuracy — and go far beyond the red chiclet-style caps found in most power supply bypass designs.
Unistage Design
Simplicity of design, especially in the direct signal path, remains a hallmark of Balanced Audio Technology’s purist approach to circuit topology. The signal in VK-85 is transmitted through only one gain stage — one free from the negative artifacts attributable to both extremes of modern preamplifier design: passive preamplifiers and multi-stage buffered active circuits. BAT’s trademarked Unistage circuit provides the ultimate simplicity of amplifying the incoming signal just once while using no global feedback to double-back on the integrity of that signal.
High-Current N-Channel MOSFET Circuit
The VK-85 circuit is based on N-Channel MOSFET devices. Solid-state designs customarily use complementary N- and P-Channel devices in the gain stage. Such configurations are easier to build but suffer from an important drawback: P-Channel devices are inherently inferior to their brethren because they are much slower. In VK-85, both sides of the waveform are handled by identical devices – in identical circuit configuration – assuring symmetry of the resulting signal.
Specifications
Inputs: 3 XLRs + 2 RCAs
Outputs - Main: 2 XLRs
Outputs - Tape: 1 RCA
Maximum Gain: 20dB
Global Feedback: None
Volume Control Resolution: .5dB
Volume Control Number of Steps: 140
Frequency Response: 2Hz to 200kHz
Input Impedance (minimum): 100k each phase
Output Impedance: 200 ohm each phase
Noise (unweighted): -96dB
Distortion at 2V output: .01%
Maximum Output Signal: 20V
Absolute Polarity: +/- via front panel switch
Power Consumption: 250VA
Tube Complement: 80VA maximum
Dimensions: 19" × 5.75" × 15.5"
Weight: 40 lbs.