Bakoon Products AMP-5570 High-End Power Amplifier

The AMP-5570 is a custom-built PA amplifier that was tested and found to have so much information that it could not be considered a PA amplifier, so it was converted to a pure audio amplifier. One of the core technologies of the AMP-5570 is the HBK(I)-IC. Its official name is HIBIKI, or "Hibiki." In the case of the SATRI-IC (Satori), its greatest feature is current input and current output, but when connected to a voltage signal such as CDP, it has no choice but to convert voltage to current. On the other hand, for the HBK(I), the circuit itself is a voltage input, eliminating the need for additional buffering and conversion circuitry. although the accuracy is an order of magnitude lower than that of an amplifier with a SATRI-IC circuit such as the AMP-5521, the sound is thicker and more powerful in line in exchange for the ultra-high accuracy of the SATRI-IC. The simpler structure without the conversion process allows audio signals to travel faster, resulting in less distortion.
Like the AMP5521 and AMP7511A, the AMP-5570 can be converted to a monaural amplifier by connecting two amplifiers together via BTL. By making it monaural, the 100W output power becomes even more powerful at 300W. Furthermore, the BTL connection can be easily switched using the input selection dial on the front panel.
The AMP-5570 comes standard with a metal film resistor attenuator, but a higher precision non-inductive wire-wound resistor attenuator is available.

Balanced Input

The AMP-5570 uses a non-reflective non-NFB SATRI circuit that does not use amplification elements, but uses two resistors to increase amplification. The OP amp makes the sound thicker than the pure SATRI-IC circuit. There are three inputs: balanced XLR, unbalanced RCA, and BTL-XLR. With balanced XLR, the signal passes through the OP amplifier, but with unbalanced RCA and BTL-XLR, the signal does not pass through the OP amplifier, making it a pure SATRI circuit.
The AMP-5570 is a new-generation amplifier without current connections, featuring balanced inputs using OP amplifiers, which Bakun products with SATRI-ICs have not had until now, and a taut, thick-wire sound designed for PA applications.
Instead of using XLR, current transmission (SATRI-LINK) was omitted. Although current transmission is obviously technically superior, you will enjoy the integration with amplifiers other than Bakun Products, and you will also enjoy the sonic changes with various RCA and XLR cables, which were not possible with SATRI-LINK.

Output	100W + 100W / 8Ω / distortion 0.8% 300W / 8Ω / BTL mono
Input	RCA (unbalanced) x1, XLR (balanced) x1, XLR-BTL (balanced mono use) x1
Gain Control	V metal film resistor ATT (standard) / non-inductive wire-wound resistor (optional)
Distortion (1KHz)	0.1%
S/N Ratio	108dB
Frequency Response	10~50kHz
Phase response	0° / 10kHz
Size	230mm(H) x 440mm(W) x 360mm(D)
Weight	18kg
Power source	100V, 120V, 220V, 240V/50,60Hz

*Bakun Products will gradually change its logo and name to SCL (SATRI Circuit Laboratory). Please note that the logo and name will be changed to SCL (SATRI Circuit Laboratory) in due course.

Metal film resistor ATT has a very high information content, very good sound separation, and a rich mid to low frequency range.
The non-inductive wire-wound resistor ATT has minimal distortion, very high resolution, rich low frequency range, and a natural sound without habit despite its dynamic sound.
Here is a sample video from a Korean owner.
Mahler Symphony No. 1, 1st movement, conducted by Michael Tilson Thomas and performed by the San Francisco Philharmonic. The resolution and speed of the Bakoon with current output are first-rate, and the rich musicality is as praiseworthy as ever, but I wondered if it would be possible to exceed this level without SATRI-LINK. The AMP-5570's sound was more informative, with a greater sense of spatiality and reverberation, and each note had more energy and substance. A little fleshier? More like the sound of a musical instrument? You can definitely feel the weight. I couldn't help but clap lightly. Next up was Jimmy Smith's "The Preacher," a live recording with a slightly rougher feel that added to the liveliness and charm of the recording. The environment and atmosphere of the time of recording are fully expressed. Of course, the SATRI-LINK amplifiers are excellent, but the AMP-5570 is far more realistic, shall we say? It is more colorful and energetic, and the charm of the music itself moves the listener. In particular, it is rich in spatial expression, and the tension around the stage and the reactions of the audience come to life.
Listening to Hans Zimmer's "Resimental Brothers" from the "Dunkirk" movie OST with ATC SCM20 bookshelf speakers, played only with AMP-5570. The very fine violin treble blooms near center right, showing off its presence. In the center of the stage, the slight sharp textures of the violins double the tension of the piece, "scrambled" by the big, thick wind instruments. The drum beat, which sounds like a heartbeat, is ample and solidly tight. The entire stage is wide and deep. No matter how tall the AMP-5570 is, it is truly amazing that a small bookshelf, not even 60 cm high and not even deep, can render a vast and deep stage.
100W per channel; those who don't know this number may find it meaningless, but the 21W 7511A BTL mono amp played on big speakers and made a mockery of the output of third-party amps. The 100W from the Bacoon would have to be a 600-700W amp from another company. Just add one AMP-5570, plug in an XLR cable, and switch the selector to BTL mono mode, and you have a simple 300W per channel monster-class amplifier. Gentle heat can be felt through the amplifier's body... I am very happy that this warmth seems to be connected to the sound quality. How about the graininess? Recent Bakoon models released have accuracy, speed, and drive, but with a thin "cool and clear" feel. The new AMP-5570, however, has eliminated that tendency. The basic sound feel is similar to that of a vacuum tube, and its ability to pull sound out of a speaker at high speed without slow corners is outstanding. The powerful driving force allows the speaker units to be positioned precisely. The bandwidth balance is therefore unbalanced. Microdynamics are well adjusted, and the nuances of the performer are excellent. In addition, the quiet background is unparalleled. The background is jet black, like a black hole. The way the instruments begin with a black silence just before the music bursts out is like a line of light coming from the darkness.
*Audio Monthly (http://www.audioht.co.kr)