Balanced Audio Technology VK-90 Preamplifier

Second-Generation Transformer-Coupled Outputs Provide Exceptional Purity

Featuring transformer-coupled, high-current, single-gain stage topology, VK-90 is the finest single-chassis preamplifier ever created by Balanced Audio Technology. Wound with Cardas’ finest copper wire, the second-generation transformer-coupled outputs catapult the performance of this fully balanced, zero-feedback design to a reference level. Each transformer comes encapsulated within a mu-metal shield for the ultimate in signal purity and noise isolation. Electrically, these second-generation transformers improve VK-90’s ability to drive low-impedance loads. Sonically, they offer greater transparency than the already revered performance established by BAT’s first-generation transformer design.
 

User-Friendly Interface and Customizable Options

Boasting one of the most flexible user interfaces in the industry, VK-90 offers customizable options that range from dimming to fading and source-naming. It can also be fully upgraded to a REX 3 preamplifier. And you can always get the volume just right courtesy of a proprietary electronic shunt volume attenuator that offers 140 steps of 0.5dB resolution. In the design, discrete metal film resistors bleed the unused signal to ground. From deep bass to extraordinary dynamics and layered transparency, VK-90 is your new reference.

Look Under the Hood: Eight 6H30 SuperTubes

More than a decade ago, BAT introduced the world to the 6H30 SuperTube. VK-90 continues the tradition by using eight 6H30 SuperTubes to form an extraordinarily high-current, low-impedance drive engine. As BAT wrote upon introduction, “comparing the 6H30 tube to a standard 6922 is like comparing a Formula 1 race car to a family sedan.” In VK-90, the signal is effectively transmitted through only one gain stage. The Unistage™ circuit provides the ultimate simplicity of amplifying the incoming signal only once, while using no global feedback to double back on the straight-through signal integrity.

Breakthrough Design: Third-Generation SuperPak

VK-90 touts Balanced Audio Technology’s all-new, third-generation SuperPak in its power supply design. It's a significant rethinking of what is possible from an energy storage device. For the first time, the BAT SuperPak features hybrid construction that incorporates two capacitors built and potted into each individual shell. An additional silver-in-oil capacitor—arguably the finest-quality capacitor offered at any price—is used as part of the Gen 3’s construction. The two capacitors are then assembled into a new low-resonance shell. The result: Low-level detail is revealed in a clear and unforced manner, while the overall sound has a beguiling sweetness and naturalness from top to bottom.

Specifications
Power Supply

Third generation SuperPak: 8x50uF with internal silver/oil hybrid construction
Silver gold oil bypass caps

Signal Path
Unistage design with only one gain block and no capacitors in signal path

Output
Second generation output transformers with Cardas OFC wiring

Global Feedback
None

Inputs
5 XLR

Outputs - Main
2 XLR

Outputs - Tape
1 XLR

Maximum Gain
18dB

Volume Control Resolution
0.5dB

Volume Control Number of Steps
140

Frequency Response
2Hz to 200kHz

Input Impedance (minimum)
100kΩ

Output Impedance
200Ω

Noise (unweighted)
100dB

Distortion at 2V output
0.005%

Maximum Output Signal
40V

Absolute Polarity
Switchable

Power Consumption
250VA

Tube Complement
8x 6H30

Dimensions
19" x 5.75" x 15.5"

Weight
42lb.