The long-awaited, Pass Labs first launch of a new pinnacle, Int 150 officially landed in Hong Kong! Pass Labs launched a combined power amplifier. Adhering to the design direction of the founder Nelson Pass, Int 150 is based on simple lines The element combines the excellence of the X150.5 post-amplifier and the pre-amplifier, and no longer uses the blue bias mounting plate as the panel mark, but uses 16mm thick aluminum material and arranged buttons to display , To distinguish this model from the other.

The aluminum selected for the Int 150 panel can completely isolate any external interference. The circuit diagram of the pre-amplification part is also composed of a patented symmetrical form, which is a pure class A circuit that can specifically balance noise. Its unique The design is enough to prove that Int150 has an extraordinary preamplifier circuit!

The later stage design is based on X150.5, all parts are matched and composed; all parts are also ultra-high accuracy. What''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s more, there are only 2 gain stages in the Int 150, especially using MOS-FET The metal oxide field effect transistor provides high-power Class A voltage at a single end, so when the output stage is properly balanced, the feedback effect is also reduced. Its streamlined design isolates the internal distribution and reduces interference.

Int 150 is completely DC and AC connected, so there is no capacitor in the signal channel. In terms of AC power supply, it also uses”Low Noise Technology”Technology, to ensure that there is a pure power supply, without the slightest vibration. Each channel uses 10 pairs of power tubes, the output is sufficient. The sound is sweet but not greasy, and the power is smooth and natural.

Technical parameters:

Rated output: 150W (8ohms); 300W (4ohms)
Gain: 32dB 18 KΩ(Unbalanced)
Input: 1 set of balance; 4 sets of RCA
Output: Balanced, 1 group each for RCA
Noise level:<300uV

Distortion rate: 0.03%
Frequency response: -3 dB at 1.5 Hz and 60 kHz
Power consumption: 150 watts @ 8 ohms; 300 watts @ 4 ohms

Dimensions: 191 mm(H) x 432 (W) x 508 mm(D)
Weight: 27 kg catty

Brand Introduction

Perth (Pass Labs)     

Nelson Pass was born in 1951 and graduated from the University of California in 1974, majoring in physics. As early as a teenager, Nelson Pass had a keen interest in audio. He tried to make his own speakers. When he was studying in college, he joined ESS Audio Company to develop Heil''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s pneumatic speakers.

Nelson Pass created Threshold in 1974, launched the world''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s dynamic Class A amplifier 800A, and obtained a US patent in 1976.

In 1977, Nelson designed another circuit to minimize or even cancel the deep negative feedback. This is the Stasis circuit, which has been used in Threshold amplifiers for 16 years. Even Japan’s Nakamichi company has also used it in amplifiers. Up this line. What many people don''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t know is that the sensational Adcom: GFA-555 amplifier launched in 1984, and the subsequent Adcom amplifiers, are all masterpieces of Nelson Pass. In addition, Nelson Pass has designed an optical coupling bias control circuit and an active acoustic wave absorber, both of which have been patented.

In 1987, Nelson Pass encountered a turning point in his career when he sold the company to Dynatech. In 1991, when the contract named Threshold was terminated, Nelson Pass ushered in a second turning point. He founded Pass Labs. In 1992, an Aleph 0 amplifier was introduced. Its power output stage adopted a push-pull design, but Nelson Pass called it a single-ended amplifier because he fully implemented the design principles of a pure Class A single-ended amplifier in this amplifier. .

In 1997, Pass Labs launched an X-1000 amplifier, which uses many technologies that Nelson Pass has invented and is proud of over the years. Among them, the most famous effect is the Supersymmetry (Supersymmetry) circuit.

“Super symmetrical balanced amplifier”

From the beginning of the audio amplifier to the present, many different design concepts have been proposed. Among them, the negative feedback technology and push-pull amplification have obvious effects. Negative feedback is a simple and cheap way to reduce distortion and expand bandwidth, but it will cause another problem: causing transient intermodulation distortion (TIM). Although the push-pull amplifier can improve the efficiency, there is crossover distortion, so that the sound at low level cannot be improved.

Nelson Pass believes that avoiding deep negative feedback as much as possible, using only partial feedback and the simplest possible circuit design is the direction of his efforts. Nelson Pass, who holds eight patents, said:“I want to try to draw a woman like Picasso in just a few simple strokes”.

In 1993, Nelson Pass conceived the patented super-symmetrical route in a simple route diagram drawn by hand. This circuit fully embodies the concept of Class A single-ended and balanced amplifiers, and gives full play to the ability of common mode suppression. For this reason, Nelson Pass enables the two sets of amplifier circuits in the supersymmetric balanced amplifier to be accurately matched from parts to circuit layout. The result is that the noise and distortion are reduced by 20 decibels. On this basis, the super-symmetrical circuit uses a special cross-correction circuit behind the input stage to connect the two sets of amplifiers, further making the noise and distortion of the two sets of amplifiers input completely the same. The following balanced amplifier circuit can smoothly eliminate these noises and distortions. The noise and distortion of the output signal can be further reduced by 20 decibels. Compared with an unbalanced single amplifier, a supersymmetric balanced amplifier can further reduce distortion and noise by as much as 100 times. Now, the super-symmetrical circuit and balanced single-ended structure have been applied to all X series front and rear amplifiers produced by Pass Labs.