Natural Harmonic Technology

Finally, a technology so advanced it's been trusted to represent the Marshall heritage in digital form. Natural Harmonic Technology by Softube brings you the versatility of the Marshall product range in one amp, with the same unmistakably classic sound.

Natural Harmonics is Softube's patented technology for digitizing analog audio systems. In Marshall JMD:1 Amplifier, it means matching the behavior of each classic pre-amp exactly, harmonic by harmonic, component by component, for any input signal and under any conditions. The result is a new era in digital amplifiers, that for the first time truly combines the benefits of digital technology, while maintaining the behavior and feel of the analog amplifier.

Harmonics and Dynamic Saturation
The core of the technology captures the exact harmonics of each amplifier. In essence, the digital replica of the analog pre-amp uses polynomial expansion of natural harmonics to generate the exact same overtone spectrum as the amplifier itself.

However, the natural behavior of the analog amplifier is dynamic and depends not only on the current input, but also on memory effects, such as power supply sag and shifts in bias. Natural Harmonics captures this behavior by analyzing the power levels in the surrounding circuits. Unlike traditional methods, such as wave shaping or other "snap shot" tools, which only capture the static characteristics of the amplifier, JMD:1 behaves like a real valve amp in all situations.

Figure 1 shows an example of these memory effects. Two sine waves with different amplitudes have been played through the pre-amp until the output has become stationary. Then the input to output voltage mapping has been plotted for these two sines. Note that the final valve stage output voltage is either 27 or 47 V for a momentary input voltage of 0.5 mV, depending on the overall amplitude of the signal over time. Also note that the curve shapes do not match for the two signals, which is captured by Natural Harmonics, but would be impossible to replicate using conventional static methods.

An exact representation of the dynamic behavior is especially important for transients, where the quick shift in loudness causes seemingly unpredictable effects. If this is not replicated exactly, the digital version will sound dull and lifeless.

The EQ and other filtering set the overall sound and character of an amplifier. Natural Harmonics digitizes these filters with minute precision, like in the example shown in Figure 2. To maintain this precision for all EQ knob settings, the interaction of the potentiometers in the passive tone stacks of the valve amplifier designs must be captured.

There is also a complex interaction between the filter stages and the valve buffers. This affects the character, but more importantly the feel of the amplifier when you are playing it. Because Natural Harmonics takes all this into account, it generates a digital amplifier with unprecedented authenticity.

So what does all this mean for you as a guitar player?

Our users often comment that Softube's amplifier products are alive and dynamic. Natural Harmonics has the advantage of being extremely responsive, from the subtle distortion in clean sounds, the power amp sag of a vintage amp, to the modern metal head roar.

When you play the JMD:1, the feel is natural and flowing, it breathes just like an all-valve amp. Moreover, the Marshall JMD:1 Amplifier brings out the essence of your guitar's tone, whether it's a seven string active pick-up rock axe or a 60's guitar with hand-wound single coil pickups.

But plots and words can only say so much. Our recommendation is for you to try a Marshall JMD:1 yourself, to fully appreciate the authentic feel and behavior of the Natural Harmonic Technology.

Marshall is a registered trademark of Marshall Amplification plc. JMD:1 is a trademark of Marshall Amplification plc. Softube is a registered trademark of Softube AB. Natural Harmonic Technology and Natural Harmonics are trademarks of Softube AB.