Recently, many people have asked me what happened to the unplugging of the op amp. Now I will give a simple explanation,

The current buffer board has a gain of 13dB (same as the official one), unplugging the op amp is quite a direct power amplifier, without the buffer board, that is, the gain will be 13dB smaller. When the op amp is unplugged, there are 4 short-circuit pins in it, which must be jumped to the other two pins of the three-pin header. When plugging in the op amp, jump back, otherwise it will affect the distortion of the whole machine.

Refer to the latest technology class D module 1ET400A, high-precision THD+N and IMD indicators, a better sense of hearing..

It is guaranteed that all parameters are tested with AP (audio analyzer), and you are also welcome to use them for comparison tests.

Every unit shipped, starting from the single board, has been tested and shipped by the AP, and its performance is 100% guaranteed.

The standard chassis of 430*220*60mm provides 8 ohms of 200 watts and 4 ohms of 350 watts of power.

The power supply adopts open-loop LLC structure power supply, full power ZVS work, rectifier tube ZCS work, so that the noise is lower.

The efficiency of the whole machine at full power is 93-94%. The static power consumption of the whole machine is 16W (measured at 220V).

Mini small chassis version, the chassis size is 310*200*60mm, the front panel adds volume knob and pure rear stage. The power and performance remain the same as the larger chassis.

Whether you are class A or class AB, class H, class TD, etc., just PK.

Due to the accuracy of the instrument, the only instrument that can measure this power amplifier is the American audio analyzer AP555 (120dB THD). Other types of instruments have exceeded the distortion of the power amplifier by themselves. The last picture is the comparison of my AP measurement.

Small chassis pure power amplifier

---High loop gain over the entire audio frequency band

This number corresponds to an unprecedented 110MHz gain-bandwidth product and produces consistent ultra-high performance across the audio spectrum that is unmatched by any audio amplifier of any technology or operational level.

--- Negligible Intermodulation Distortion (IMD)

Low IMD means high resolution and stable stereo sound across the entire spectrum, even in very complex and busy signals, which is a good measure of how the amplifier handles complex signals

--- Distortion (THD) remains extremely low at any frequency and at any power until peak clipping

Completely lossless restoration of preamp sound characteristics and the ability to reproduce any type of music without favoring genre or production style. (That is to say, it is as clear and restored as a pure cup of boiled water. You can choose different pre-processing and specific MSG for any style you want)

---- Negligible output noise

I can hear any noise even with my ear-mounted speakers. Quiet and rich and detailed sound like late night, even at very low playback volume.

---High Power Supply Rejection Ratio (PSRR)

The machine has no special requirements for power quality. Simple off-the-shelf power supplies won't degrade audio performance either.

---Load-invariant frequency response and negligible output impedance

It can easily handle difficult speakers, its frequency response will not change with the load (most Class D amplifiers will change the frequency response with the load), the ultra-high damping coefficient, and the low frequency is more surging.

--very high conversion efficiency

Alternating MOSFET Zero Voltage Switching (ZVS) operation over the full power range without degrading audio performance

---Very clean clipping and clip recovery

Clipping is very clean and recovers instantly without "hanging". Current limit is also instantaneous and glitch-free. This guarantees minimal audible distortion when pushed into clipping or overload protection

The following data is ATS-2 test. Due to AP background performance, some performance cannot be tested to the lowest point. The best test can only be measured by AP555.