Balanced Audio Technology VK-655SE Power Amplifier
The fully balanced VK-655SE power amplifier is the ultimate expression of BAT amplifier engineering. Available in stereo or monoblock configuration, it features only two gain blocks in a high-power, zero feedback, and purely symmetrical design. A true dual-mono component featuring independent channel assemblies, power transformers, and separate power cords for the left and right channels, the purist approach-based VK-65SE yields maximum soundstage width and depth. Finite micro- and macro-dynamics are reproduced with ease. A revised power supply incorporates the same second-generation oil-filled capacitors used in BAT’s flagship REX II preamplifier, dramatically lowering the noise floor and portraying grain-free, extra-refined harmonics.
The VK-655SE power amplifier represents the ultimate expression of solid-state amplifier design from Balanced Audio Technology. Available as either a stereo or mono-block unit, the VK-655SE is a reference amplifier that features only two gain blocks in a high power, zero feedback, and purely symmetrical design. Unlike most solid-state amplifiers that are clinical and fatiguing in their sound, the VK-655SE offers a richly textured portrayal of music that is simply beguiling.
Only Two Gain Stages (with Zero Global Feedback)
The VK-655SE’s elegant signal path follows the Balanced Audio Technology purist approach of using zero negative feedback to achieve the design goals of wide bandwidth and circuit linearity. The whole amplifier circuit consists of just two gain blocks! The theoretical ideal for any power amplifier would be to have only one gain block, but this has been achieved only with the limitation of low power output. Thus, the VK-655SE is at the zenith of simplicity for any modern high-power amplifier design.
Needless to say, the VK-655SE is fully balanced from input to output. To complement the inherent simplicity of this fully balanced design, only the highest grade parts are used throughout, yielding a superbly transparent insight into the musical event.
N-Channel MOSFET Devices Used
The VK-655SE circuit is based entirely on N-Channel MOSFET devices.
It is customary in high power amplifiers to use the complementary N- and P-Channel devices in the output stage. Such configurations are easier to build, but they all suffer from one important drawback: the P-Channel devices are inherently inferior to their N-Channel brethren. They are simply much slower. Pairing the faster N-channel devices with the slower P-channel devices is like pairing Ginger Rogers with her horse on the dance floor – instead of Fred Astaire. You will never get perfect symmetry when using devices with such a wide discrepancy in speed.
In the VK-655SE power amplifier, both sides of the waveform are handled by identical devices, in identical circuit configuration, assuring ultimate symmetry of the resulting signal.
600 Watts per channel (Stereo) into 4 Ohm
The VK-655SE power amplifier is a high-current solid-state design that offers a robust 600 watts per channel into a four ohm load (stereo version). In essence, the VK-655SE power amplifier can easily drive most any speaker ever made. Obviously, the mono-block version makes this statement “doubly true.” The Balanced Audio Technology VK-655SE mono-block power amplifiers also contain 1800 joules of energy storage. This is enough stored energy to lift most speakers over one meter off the ground!
High power combined with high energy storage yield the dynamic sound that is a BAT hallmark.
True Dual Mono Design
The VK-655SE power amplifier is a true dual-mono design featuring independent channel assemblies, power transformers, and even separate power cords for the left and right channels. This purist approach to dual-mono construction offers benefits in reproducing the maximum soundstage width as well as depth. In addition, the micro, as well as macro, dynamics of music are simply reproduced with ease.
The revised power supply of the VK-655SE now incorporates the same second-generation oil-filled capacitors used in Balanced Audio Technology’s new REX II Preamplifier. These second generation oil capacitors increase the high quality filtering capacity by an order of magnitude over the first generation oil parts. The result is a dramatic lowering of the power amplifier’s noise floor combined with a grain-free, yet textured, and more refined portrayal of musical harmonics.
Intelligent Power Upgrade
The VK-655SE can be ordered from the factory as either a stereo amplifier or as a mono-block in the VK-655SEM version. Balanced Audio Technology also provides a transparent upgrade path that allows the owner of a stereo VK-655SE to easily convert to a mono-block at any point in time.
Unlike competing designs, there is no need for the user to trade their amplifier in to obtain more power. With the VK-655SE Power amplifier, the user can simply convert their existing VK-655SE to a mono-block, and then order a second VK-655SE mono-block to match. Technically, the stereo to mono-block conversion is accomplished by simply paralleling the inputs and outputs. This means that “the sound” only gets better as the VK-655SE mono-block current delivery is doubled. The added current delivery makes the sound of the VK-655SEM effortless – more akin to that of the master tape.
Dynamic responsiveness remains the recognizable difference between live and reproduced music. The VK-655SE couples quickness, slam, and dynamic range with a wide, deep soundstage and an exquisite fidelity to the timbre and texture of instruments and voices. Indeed, the sound of the VK-655SE and REX II Power amplifiers converge upon the same ultimate goal – the sublime reproduction of music – independent of the devices employed. We invite you to visit your BAT audio specialist to hear the extraordinary performance of the VK-655SE for yourself.
All you need to do is listen!
Output per channel at 8 Ω / 4 Ω: 300 W / 600 W
Output in Mono Configuration 8 Ω / 4 Ω: 400 W / 700 W
Frequency Response: 3 Hz to 250 kHz
THD at full power: 0.2 %
Input Impedance - stereo version: 100 kΩ
Input Impedance - mono version: 50 kΩ
Gain (Nominal into 8 Ω): 26 dB
Remote Control: 12 V Trigger Input & Output
Power Consumption (Idle / Full Power): 400 W / 2000 W
Dimensions (WHD): 19" x 9.5" x 23.5", 483 x 242 x 597 mm
Weight: 120 lb