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Waversa Systems Incorporated Amp 2.5 MKII class D digital integrated amplifier

Waversa Systems Incorporated Amp 2.5 MKII class D digital integrated amplifier

4,500.00 USD


  • Price 4,500.00 USD
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Description

Waversa Systems has taken a unique approach to music reproduction by producing a mix of
high-quality analog tube amplification and phono preamps harmoniously complimenting pure
digital streamers, D/A converters, and dedicated Roon Core servers. While we have examined
Waversa's unique digital signal processing above in Appendix 25, this technology is also
implemented through a different and equally novel approach to amplification, culminating in its
PBTL (Para Bridge-Tied Load) output stage. This fully digital amplification technology percolates
throughout the entire Waversa solid-state amplifier line, including the WAMP 2.5 MK2,
WSlimLITE, WSlimPRO, WMiniHPA, and WMiniAMP.

The WAMP 2.5 MK2 is at the heart of the Waversa portfolio as an integrated digital amplifier
with enormously high output power. However, if you cringe at the thought of "digital amplifiers,"
you should now read on especially carefully to understand the Waversa difference.

 

For a summary of this amp offers please read about them under: What's Best Forum

Digression: To understand the difference between a Class D amplifier and a "digital amplifier,"
it is necessary to distinguish the terms PCM and PWM.

PCM (Pulse Code Modulation)

PCM is a process that converts analog signals into digital signals. It assigns numeric values to
the analog signal, the famous ones and zeros that digitally represent the analog signal. The two
variables, "word width" and "sampling rate" are decisive for the quality of conversion in the
PCM process. The best way to grasp this is to imagine a coordinate system: the horizontal, i.e.,
the x-axis describes the time course (sampling rate), the vertical, i.e., the y-axis, the amplitude
(word width).

The sample rate determines the frequency of sampling within a specific time - in the audio
sector, this interval is traditionally 1 second. The finer the grid on the x-axis (the higher the
sample rate), the more precisely an analog waveform manifests in the x and y coordinates. The
second significant quantity to be digitally recorded is the volume of the analog signal. The so called

word width defines volume and is expressed in bits. Specifically, the word width
determines how many digits the number generated during digitization can have. Usually for
audio, 16 or 24 bits are used - rarely 32 or 64 bits. The more digits a sample has, i.e., the higher
the number of bits, the more dynamics can be reproduced.

So PCM creates a certain number of reading values, each with a certain amount of information.
For example, CDs contain digital PCM data with an information amount of 16 bits (either 1 or 0)
in each of the 44,100 read values per second (44.1 kHz). An analog signal of 1 second is
represented in PCM as a series of 44,100 "read values" (horizontal axis in the coordinate
system), each with different "heights" of 16 bits maximum (vertical axis in the coordinate
system).

PWM (Pulse Width Modulation)

PWM is also a method for converting analog signals into digital signals. PWM also represents
the analog signal through numeric values. Unlike PCM, however, PWM expresses the analog
signal by the width of a pulse and not the extent of a real value. While PCM represents the
analog signal's amplitude by the different heights of the read values, PWM varies the pulse
width. The ones of each PWM pulse represent the 0 ~ 180 degree part of the sine wave of the
analog signal, and the zeros of the PWM pulse represent the 180 ~ 360 degree part of the sine
wave. The higher the amplitude of the analog signal, the wider the PWM pulse becomes.


Class D

The "D" in "Class D" does not refer to "digital," but solely to the order of Class A, Class B,
Class AB, and Class C. Class D works with PWM. After direct conversion to PWM, the analog
signal is usually amplified by a switching regulator and an output stage (instead of analog
amplifying elements such as transistors or vacuum tubes) using a delta generator. The
amplification is achieved by varying the switching time; it depends on the width of the PWM
signal (see above).

The amplitude and frequency of the PWM signal are constant; the music information is
exclusively in the pulse width.

Therefore, Class D amplifiers are also called switching amplifiers. Finally, the amplified PWM
signal is "smoothed" by a low-pass filter in the output stage, i.e., converted back into an analog
signal and passed on to the loudspeaker.

The Waversa WAMP 2.5 MK2 has an entirely digital signal processing path before the actual
class D amplifier. The WAMP 2.5 MK2 converts all analog input signals into PCM format via a
high-performance 32-bit A/D converter and an FPGA-based (Field Programmable Gate Array, a
programmable digital device) WAP (Waversa Audio Processor) chip, which then converts the
PCM signals into PWM format.


PWM conversion is only one of many tasks of the WAP, which is also used in Waversa’s D/A
converters and streamers. In the course of signal processing, WAP and the WAP/X algorithms
improve the sound quality, ensure a linear frequency response, and increase the resolution by
mathematical calculations directly on the chip instead of using lossy analog methods like
resistors and coupling capacitors.

So how does the Waversa WAMP 2.5 differ from "normal" amps?

1. Higher resolution: The analog signal is converted by A/D conversion into a digital PCM signal
with high resolution (32 bit / 384 kHz). This is the most crucial difference from other Class D
amplifiers, which convert the analog signal directly to PWM. The Waversa audio processor then
samples the PCM signal up to 1.5 MHz, a critical step in maximizing resolution before further
processing. The extremely broadband frequency response of the Wamp 2.5 MK2 from 0Hz to
160kHz is one of the upsampling results.

2. Transfer of the PCM clock to PWM via WAP: PWM has the inherent disadvantage of not
having a digital clock signal. However, the WAP chip evaluates the PCM time interval and then
passes this information on during the conversion to PWM.

3. Improved frequency response linearity through WAP: The WAP chip's mathematical
calculations guarantee a considerably higher resolution and a linear frequency response. All
algorithms are executed in real-time directly on the WAP chip. The amplitude boosting problem
in the medium frequency range, one of the most significant disadvantages of analog amplifiers,
is entirely solved by the WAP chip.

4. Further digital corrections are made on the WAP chip to improve the detail and the spatial
representation regardless of the volume. Analog amplifiers cannot achieve this, so here is a
unique advantage of WAP technology.

The two most essential corrections based on WAP are:

a. WUS (Waversa Ultra Sound): With the help of the unique signal processing of the WAP chip,
resolution, spatial impression, and airiness can be varied. The user can choose between three
modes creating varying high frequency extension.

b. WAP/X: Audio tubes have a distinctive, pleasant sound signature, particularly good at
conveying delicate information about even-numbered harmonics. These harmonics are lost to a
great extent during digitalization. WAP/X is an algorithm based on the overtone behavior of
audio tubes, which reconstructs the 2nd, 4th, and 8th harmonics of real music lost during
digital recording or the digitization of analog recordings. Thus, digital music also sounds
touchingly real, vividly spatial, and natural.

5. PBTL (Para-Bridge-Tied Load): The WAMP 2.5 MK2's enormous output power of 400 Watts
into 4 Ohms is made possible by a parallel structure of four "normal, inverse, normal and
inverse" phase output amplifier modules per channel (the WAMP 2.5 MK2 has an authentic
dual-mono design). In this way, the gain factor in each of the individual output amplifiers can be
reduced, thus reducing by multiples the conventional artifacts (a hardened not very subtle
sound in bridge mode), which can result from a (too) high gain factor.

We hope this explanation has succeeded in making it clear that the WAMP 2.5 MK2 is not just a
generically designed 'digital' amplifier looking to extract performance through quality
componentry or good execution, as is the norm among its competitors, but something radically
different: it harnesses the full power of the Waversa Audio Processor (WAP) to create a pure
digital amplification product. The WAMP2.5 MK2 goes to the heart of the goal of Waversa to
fully utilise its unique digital technology, with its design percolating throughout the entire
Waversa amplifier line, including the WSlimLITE, WMiniHPA, and WMiniAMP

This is a used unit but at full current manufacture specifications version MKII and certainly capable of driving any speaker.

 

Please note two light scratches at the top corner of the chassis on each side - likely from the footers of another component placed on top.

I would rate this an 8/10 condition.  Retail is around $7500.  

 

MAIN  FEATURES • Digital Integrated Amplifier • Monorail Construction EXCLUSIVE TECHNOLOGIES • High-precision 32 bit / 384 kHz A/D converter • WAP - Waversa System Processor 32bit 1.5MHz PHYSICAL CHARACTERISTICS • Chassis: Aluminium • Colour: Silver • Inputs: 2 x Balanced XLR, 3 x Single Ended RCA, 1 x Coaxial Digital • Outputs: 2 x 5 Way Binding Post • Dimension: W 440 x L 330 x H 145 mm • Weight: 13 kg / 28.6 lbs. • Power supply: Built in 180~240 VAC @ 50~60Hz S SUPPORTED AUDIO/VIDEO FORMATS •COAX: up to 24/192KHz SPECIFICATIONS •LinuxHigh precision 32bit ADC and PWM processing •FPGA based Waversa Audio Processor (WAP) type 2 applied with built-in 768KHz high-end upsampler •Ultra Low Power Universal Serial Bus Audio Class 2.0 with High Precision Clock •Digital PWM based class D amplifier with PBTL 200W per channel 8 Ohm •8 Level Display Brightness Control 



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