A HIFI Class B Amplifier Refer to NAP140 Circuit

A HIFI Class B Amplifier Refer to NAP140 Circuit

Power Amplifier of Named Naim is one of those products worshiped by audiophiles like as Linn turntables. Though its unassuming appearance, but it has won the hearts by warm mellow tone. Naim price is not low, people who really know what was the expert are willing to spend money to buy it. If you are truly listening to music, you will feel that once you owned and not much else for this amplifier.

I love this circuit Naim NAP140 as much love for the 1969 circuit. Because it sounds isn’t worse than 1969, and its output power is far better than 1969. One feature of NAP140 amplifier architecture is its mostly second-harmonic distortion, so the tone is somewhat like as tube amplifier charm. But the difference is that it is very rewarding that the distortion of tube amp to achieve 0.1%, but this circuit can be achieved 0.01% distortion.

IWISTAO HIFI Power Amplifier 80Wx2 Stereo NAP140 Mellow Soft Sound Tube Taste Black from IWISTAO HIFI MINIMART1 on Vimeo.

We made this HIFI amplifier to refer to Naim Nap140 designing, and hope in keeping NAP140 original fine circuit architecture as same premise, to use new devices, greatly improve the operating voltage and output power, improve stability, and to Try to do something to improve the circuit (for example, the circuit adapted to work class A state). The original unit is very popular with enthusiasts respected, but also the price of its second-hand is nearly USD 2000. We do not engrave it, and cannot do it, only with reference to its excellent circuit configuration. The amplifier’s circuit is very mature, stable, ultra-low power consumption, driving and control force is very, very good, far better than integrated circuit amplifier or similar circuit at same output power, it is cannot be compared by them. More commendable is that the sound of this Class B circuit is mellow and soft as same as class A one at low power consumption.

Its output power is able to reach 80W at 8 ohms and class B state.

Features

1. Basically to be faithful to H140 classic circuit.
2. Add upc1237 speaker protection system, switch absolutely no impact sound while performing midpoint of DC protection, to prevent damaging or burn your expensive speakers due to the amplifier circuit.
3. Integrate volume control potentiometer.
4. Integrate a two inputs switch on the front panel, you can switch the input source via the front panel.
5. Add a midpoint adjustment circuit on differential input, generally midpoint can adjust to 5mV or less.
6. The finished unit with about 2KG heat sink, while it is whole aluminum design, this benefit other parts of the casing become heat sink also in addition, so that the total heat dissipation area greatly increased. Its actual operating temperature up to 40 degrees, low-carbon green!
7. Use a special custom 200W HIFI OFC toroidal transformer, ensure enough reserve power!
8. Use a lot of HIFI elements like as ALPS27 potentiometers, high-grade RCA connect, ELNA capacitors and HIFI chemicals one. Sound’s quality is the most important thing.

More Details, please visit 

HIFI Power Amplifier 80Wx2 Stereo Refer to Naim NAP140 Mellow&Soft Sound Tube Taste Black Whole Aluminum Casing 

Shigeru Wada Tube Preamplifier Output Quality Sound

Shigeru Wada Tube Preamplifier Output Quality Sound

Tube preamplifier is used as tone processing amplifier between sound sources and power amplifier, so it is so-called, preamplifier output quality sound, power amplifier stage output power, which indicate that a quality preamplifier plays a key role in the entire audio amplifier system. Therefore, it is very important that the sound system choice preamplifier. Tube preamplifier has its special tube soft and warm sound, its listening sense has been ranked the first reputation and praise in all preamplifier, it can be applied to tube power amplifier, transistors one, and active sound system, especially for transistor amplifier, it can make the exists boring, blunt digital taste of your original system becomes rounded, sweet, tube taste is very rich; When listening to human voice, especially for the song folk song female voice, the sound is very warm, very sweet.

Shigeru Wada Tube Preamplifier

I bought CD player that is earlier 16bit models a decade ago, for adding musical charm to the sharp and dry digital sound to improve listening sense, but also because the tube is easier to produce pre-production and high rate of return for many years also try to produce a variety of line sound effects of a variety of tube pre-level, such as Shigeru Wada and Marantz.

The two circuits of preamplifier are more familiar and well-known. Through several repeated proofing tests and contrasts, found Shigeru Wada look is extremely good from performance and sound quality. It is to keep Marantz7 mellow and rich flavor of the characteristics of music, while dynamic, transient, high and low frequency response, analysis of signal-to-noise ratio better than Marantz 7, and Keep pace with each other in the sound field, penetrating sense with Marantz7 . In fact, this is only analysis from Shigeru Wada’s circuit, it is not difficult to find that its preamplifier is made of a very good stability by high-gain double three-tube, composed of two stages voltage amplification, only one tube has 10 times signal amplification capability with a very high sensitivity.

Shigeru Wada Tube Preamplifier with Black Chassis

And its power stage is also known by most of audiophiles, a very superior performance double tube 12AU7 composed of the radio level follower which using SRPP cathode output follower circuit that is similar with SRPP, it is different with the ordinary voltage amplifier stage, it does not have the voltage gain, the role is only current amplification and to reduce the output impedance, so that the load capacity is much larger than the co-screen pole follower, whether in high frequency response or signal to noise ratio. Compared with Marantz 7, it greatly improve low-frequency response, signal-to-noise ratio is also improved in varying degrees, in terms of sound performance is more balanced and comprehensive. So the design of Shigeru Wada preamplifier is very reasonable, both a very high sensitivity, but also a very good carrying capacity, no matter what kind of power stage is more flexible, play most vividly.

Who is familiar with Shigeru Wada are known, characterized by prominent human voice, better midrange. It is appropriate to even harmonic distortion when tube working, which will not worsen listening sense, on the contrary increase the sound of beauty, make the sound be more smooth, some details will be more prominent like to do a certain optimization, especially when playing human voice, there will be some feelings of rich taste out, tube taste is very strong. It will not only play in human voice will give charm, but also playing some pieces of music, such as some indoor recording of the violin, saxophone, jazz and other music, will also have a unique style.

Features

1.       Circuit used Shigeru Wada improved field circuit of the original version; excellent PCB circuit design, reasonable, regular, symmetrical device layout, and strictly follow the rule of single point grounding line.

2.       Whole aluminum chassis especially made for Shigeru Wada with very fine black brushed oxidation, looks shiny, extraordinary taste.

3.       And it used whole aluminum solid sand drying high-end knobs. the plate thickness of body is all 2.8mm, panel thickness is 8mm with high precision milling machine finishing, and tube seats positioning accuracy, holes-cut is smooth and sleek.

4.       Power transformer is up to 120W (EI8642 / H50 film) with a horizontal cover, and the primary and second windings of transformer are shielded strictly. Left and right channel of filament voltage has been supplied by independent winding respectively; completely eliminate mutual crosstalk, good power transformer output good sound.

Product specifications

1.       Input sensitivity : 200mv

2.       Output voltage: 2V (RMS THD <0.03%)

3.       Signal to noise ratio :> 95dB

4.       Frequency response : 10Hz-50KHz (-0.5dB)

5.       Input impedance: 250K ohms

6.       Output impedance: 150Kohm

7.       Input voltage: AC 110V or 220V/50~60Hz

8.       Whole power consumption: < 50W

9.       Dimension(W*D*H) 360mm * 190mm * 140mm

10.   Net Weight: 4.5Kg

11.   Tubes: 12AX7 * 2; 12AU7 * 2 ; 6Z4 * 2.

12.   Accessories:

Power cord x 1

More details, please visit,

Tube Preamplifier Pure with Shigeru Wada Circuit Tube 12AX7 12AU7 6Z4 Rectifier Whole Aluminum Chassis HIFI Audio 110V/220V