The AMG STA-SE incorporates numerous cutting-edge innovations in power amp design. Its exceptional features include a 1M Ohm input impedance, high instantaneous current for efficient power delivery, a >700kHz switching frequency, and a unique combination of Single-Ended Non-Negative Class A module with Double Feedback Class D module, resulting in a powerful 300W mono amp output. The exceptionally smooth sound characteristic of the AMG STA-SE sets it apart from other top NuPrime amps like the AMG One, Evolution STA, and Evolution Two. *Existing AMG STA can upgrade to AMG STA-SE. Please contact your country distributor or service center. The front panel of the AMG series epitomizes its essence. Crafted from a 15mm hardened aerospace aluminum alloy, it undergoes a meticulous 48-step milling process using a four-axis CNC machine with a diamond cutter. Design features like the 3D “floating” logo, the contoured surface surrounding the front panel switch, and the precision diamond-cut edge elevate the AMG series, bringing the quality of ultra-high-end audio products within the accessible range of this series. Technology Special Edition Enhancements (AMG STA-SE vs AMG STA) The enhanced Class-D circuit boasts a 30% reduction in MOSFET temperature during high-speed operation exceeding 750KHZ (more precise PWM waveform), enhancing energy efficiency and ensuring sound stability. In terms of sound performance, this results in a more relaxed and natural expression. Employing aerospace-grade ultra-high-precision resistors with a minimal error margin of 1/1000, our system exhibits ultra-low drift, with a temperature drift coefficient of only 15 parts per million. Generally, it’s rare for amplifiers in this price range to use such ultra-precise components. This ensures that negative feedback sampling remains unaffected by external temperature variations and environmental factors, enhancing accuracy and detail in music reproduction. The result is a clearer presentation of musical intricacies, facilitating easy comprehension of musical expression. A newly devised and fine-tuned secondary negative feedback circuit enhances sound delineation and imaging precision, yielding sharper sound contours and improved spatial positioning. Leveraging a large-capacity current power supply capacitor design and employing low-impedance routing for the primary current path, our system enhances dynamics and energy. Instantaneous supply current is boosted to 1.5 times that of the original AMG STA design. With a Class D oscillation fundamental frequency ranging between 700 and 750KHz, our system achieves excellent high-frequency extension and sound resolution. Our newly developed AC power supply minimizes external radiation noise interference, while a redesigned SMPS power module ensures an ultra-low noise system power supply for circuits that required low voltages. The result is a darker and wider sound background, enriching the auditory experience. AMG STA PCB integrates ground wire shielding to isolate external interference. The 300 Mhz bandwidth JFET provides ultra-high input impedance and wide-band fast response. The dynamics of the design and the single-ended Class A circuit enriches the natural second harmonic. This design allows the most delicate details in the audio signal to carry through the chain. The level of transparency in sound reproduction is genuinely astonishing in this class of equipment, with a deft in creating a highly detailed sonic imagery. The AMG-STA uses the “Single-Ended, Non-Negative Feedback” Class-A module partners with a new “Double feedback” Class D circuitry. The Class D oscillating frequency has increased to 700kHz, which is 1.4 times that of the STA-9. Power Circuit The power supply uses a 380W special winding power transformer, which has 30% more peak power output of a similar volume transformer. The AC power input from the Inlet Connector to the power transformer utilizes a high current welding line to provide maximum power transmission. A 20A lock wire terminal block connects the transformer to the motherboard, in parallel with two10A peak current rectifiers. The main current path, adopting a large-capacity current design, uses a low-impedance copper plate to maximize power delivery to the amplifier circuits. How did AMG STA-SE mono achieve better sonic characteristic, in addition to more power than AMG STA-SE stereo ? The standard method for bridging a stereo amp into mono employs a series of op amps (OPA) in order to invert the input signals to one of the stereo amp, thereby creating an opposite phase, which can then be combined to increase power. Conversely, the AMG STA-SE’s innovative bridging circuit utilises a design we call Single-Ended Direct-Inject Bridge Technology, in which the mono mode, in addition to acquiring more than double the power, sounds livelier and more dynamic. Listening Impression With improvements to every area, the bar has been raised for what is achievable with audio performance in small form factor. AMG STA-SE sounded ultra smooth and relaxing. Detail, resolution, dynamics, and speed are in the AMG One ballpark, yet the sound is quite different. Drawing comparison with the Evolution STA, they shared a trait of ease in reproducing the details of the recording comes afore. However, AMG STA -SE does things differently. While the Evolution STA has that inviting warmth, the AMG STA-SE wants to allure the listener. Hence, instead of glitz and glamor, which pulls you in quickly into the performance, the AMG STA-SE has a demeanor that slowly brings you into the music. Tonal qualities of the AMG STA leans toward being full and rich, so instruments and vocals seem to gain extra body, weight, and harmonic richness. It makes Jazz and Vocal pieces highly addictive. The sound stage has an attractive characteristic. A linear presentation is like having floodlights shining on all the performers such that everyone can be seen equally well. The AMG STA-SE, however, has more of a spotlighting effect, where performers are focused on getting your attention. But the sound stage is still wide and deep. With a larger soundstage, clear focus, more direct sound, and increased detail, the overall impression is that everything becomes incredibly transparent, with a significant enhancement in the sense of presence and realism.
