Balanced Audio Technology VK-85 Preamp and REX 300 Power Amp

May 2024 | NEWS, AMPLIFIER

Balanced Audio Technology (BAT) introduces the VK-85 Preamplifier and REX 300 Power Amplifier, fully
balanced solid-state designs that also offer some of the finest sonic attributes typically found only in tube based circuitry. This is achieved through numerous in-house developed technologies, which continue to evolve, with the goal of bringing the end-user closer to the power of a live music experience.

The REX 300 is essentially a lower powered version of the highly regarded 500W/ch. REX 500; think about trickle-down
technology at its finest. Not everyone needs so much power, thus part of the reasoning behind the REX 300 which
outputs 200W/ch., all the while, using virtually all of the exceptional advanced circuitry found in its big brother.
Starting with a massive power supply, the REX 300 employs the same TWIN-Path (split power supply topology) found in the REX 500. These individual power paths allow the supply to deliver much greater current than traditional designs. This power supply design is further enhanced by BAT’s new “SuperPak Quattro” capacitor bank which provides four levels of power-supply filtration. This is achieved through the use of third-level premium silver foil/oil capacitors which are joined by an X-cap. The result is music’s textural beauty, tonal density and harmonic accuracy become far more evident. Also, since the best sounding fuse is no fuse at all, the REX 300 follows its big brother with a protection circuit that eliminates internal fuses, permitting it to handle higher currents without impeding the circuit’s operation.
REX 300 stands at the zenith of simplicity for modern high-power amplifier design thanks to an amplifier circuit that
consists of just two gain blocks. As well, the output stage is based entirely on “N channel” MOSFET devices (as opposed to the traditional use complementary “N” and “P” channel devices where “P” are inherently slower and therefore inferior), allowing both sides of the waveform to be handled by identical devices in an identical circuit configuration, assuring symmetry of the resulting signal.
Finally, there is the “Intelligent Power Upgrade” where a REX 300 can be ordered as either a stereo amplifier or as a
monoblock. BAT provides a transparent upgrade path that allows an owner of a stereo REX 300 to easily convert it to a
monoblock configuration at any point. There’s no need to trade-in the amplifier to obtain more power. A simple
conversion of a customer’s existing stereo REX 300 to a monoblock and the ordering of a second REX 300 monoblock
to match. Technically, the stereo to monoblock conversion is accomplished by paralleling the inputs and outputs.

The VK-85 Preamplifier is the result of a new design strategy that benefits from several improved in-house circuit
technologies, including the aforementioned “SuperPak Quattro” and the “Second Generation Transformer Coupled
Outputs”, as well as proven BAT circuits such as Unistage Design, High-Current N-Channel MOSFET Circuit and Shunt
Volume Control.
The new “SuperPak Quattro” dramatically lowers the VK-85 preamplifier’s overall noise floor while the new “Second
Generation Transformer Coupled Outputs” results is a highly open and dynamic sound, free of both the sonic and
longevity drawbacks common to capacitor coupled designs. While all BAT preamplifiers use transformer coupled outputs, what is used in the VK-85 is on a whole new level of premium output transformer design.
Unistage Design in a preamplifier serves the purpose of maintaining the integrity of the input signal. In the VK-85, this is
achieved using 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. This continues to be a hallmark of BAT’s purist approach to circuit topology.
The VK-85 circuit is based on High-Current N-Channel MOSFET devices where both sides of the waveform are handled
by identical devices – in identical circuit configuration – assuring symmetry of the resulting signal, just as described for
the REX 300. The highly accurate volume control employs a proprietary electronic shunt volume attenuator with 140
steps of 0.5dB resolution. This is accomplished using a single Vishay bulk foil resistor – the most precise and thermally
stable resistor available – per phase; This is all that’s in the signal path. Discrete metal film resistors are used to bleed the unused signal to ground. The 140 steps give precise repeatable volume settings that sound continuous to the human ear.

The BAT VK-85 Preamplifier will be available in Q2, 2024 with an MSRP of $12,500.00 USD

The BAT REX-300 Power Amplifier will be available in Q2, 2024 with an MSRP of $15,000.00 USD