Copy PASS A3 Fever Pure Amplifier DIY HIFI 30W Single Terminal Pure Class A Amplifier Machine RCA/XLR Input

Basic parameters:

Amplifier dimensions: Width 360, Depth 350, Height 150

Power: 30watts @ 8ohms; 60watts @ 4 ohms

Distortion rate @ 1 KHz: 1% at rated output;

0.003% @ 5 watts into 8 ohms

Input impedance: 10kohm balanced, 18kohm single ended

Output noise:<300uV unweighted 20-20kHz

Dynamic range: 140dB

Gain: 20dB

Signal input support: balanced input or unbalanced input

This device is based on the original PASS A3 circuit from the United States, with a single ended pure Class A 30W output power and excellent driving force. The 30W pure Class A power is sufficient to handle most difficult to push speakers under 8 inches on the market!

PASS A3 Introduction and Production Materials:

The PASS A3 Fever Amplifier, as a classic pure A-class single ended circuit of the PASS A series medium-sized single ended pure A-class amplifier in the United States, has a classic and simple circuit with good sound, and is highly sought after by DIY players. Its popularity has not decreased for many years, which is enough to witness the charm of PASS A3 single ended pure A-class sound. Compared with Mark's 1969, the amplifier is larger, the low-frequency diving is deeper, and the voice is more toxic than 1969. It is a very worthwhile single ended pure A-class amplifier to listen to!

The design and production of this machine have spent a lot of effort to create a perfect and simple wiring HIFI level fever equipment. PASS A series machines have very high power requirements for the whole machine. This machine uses two 300W customized pure copper rings with fever, which are independently powered from left to right. The sound performance is very warm, low frequency dynamic is very sufficient, and the dive is extremely deep. It is equipped with eight 30A Schottky rectifiers, 24 ELNA FOR 10000UF audio fever capacitors, and the power filter is up to 240000 UF, making the power system of the whole machine very abundant. This is also the key to PASS good sound. High voltage, high current, too dynamic, the power supply lines do not move, and it is as stable as a mountain! The soul of the PASS A series single ended pure Class A amplifier power system! Many audiophiles only imitate its circuit without relying on heavy power, which greatly reduces the sound quality!The materials used for the amplifier board are even more cost-effective, with DALE military grade fever resistors and ELNA Brown Shen second-generation fever capacitors produced solely for music. The only drawback is the high cost, and DALE resistors are highly praised by audiophiles for their low noise and comprehensive sound quality performance!

PASS A3 uses 4 IRFP240 field-effect transistors per channel for amplification, with precision matching under high current power transistor conditions. The output current is large and the driving force is good. The pure Class A power of 30W at a single end is sufficient to push most popular floor and bookshelf boxes on the market! The power supply of the whole machine starts with a soft start, and the highly sensitive speaker protection circuit always guards your beloved speaker!

Detailed pictures of the entire machine production process