Common audiophile audio ICs

1. TDA1521

TDA1521 / TDA1514A are two chips specially designed and launched by Philips in the Netherlands for the low distortion and high stability of digital audio during playback. They are used to connect the CD player for direct output of particularly good sound quality.

The parameters are: TDA1521 output voltage is 2 & TImes; 15W when the voltage is ± 16V and the impedance is 8Ω, the distortion at this time is only 0.5%.

The working voltage of TDA1514A is ± 9V ~ ± 30V. When the voltage is ± 25V, RL = 8Ω, the output power reaches 50W, and the total harmonic distortion is 0.08%. The input impedance is 20KΩ, the input sensitivity is 600mV, and the signal-to-noise ratio reaches 85dB. The circuit is equipped with waiting, quiet and noisy state, with overheat protection, low offset voltage and high ripple suppression, and the thermal resistance is extremely low, with excellent high frequency resolution and low frequency strength. The sound is transparent and pure, the bass is full and thick, the treble is clear and bright, and it has the charm of a tube.

The above two power amplifiers have relatively few peripheral parts. They are "fool" type power amplifier chips, which are very suitable for primary enthusiasts to assemble. As long as they are in accordance with the circuit diagram, no debugging is required to obtain good results. Because the input level of the chip is relatively low, we do not need a preamplifier in production, as long as it is directly connected to our computer sound card, optical drive, and Walkman. The famous computer multimedia speaker rambler also uses these two chips.

Second, LM3886

LM38863TF is a high-power audio power amplifier chip launched by American NS (National Semiconductor Corporation) in the early 1990s.

The main parameters of the chip: the working voltage is ± 9V ~ ± 40V (recommended ± 25V ~ ± 35V). The continuous output power reaches 68W (peak 135W) when RL = 8Ω. If the output power when connected to BLT can reach 100W, and its distortion is less than 0.03%, its internal design has a very perfect over-consumption protection circuit.

Its sound is very sweet, the sound quality is mellow, and has the charm of a tube, so it is suitable for playing soft music.

NS also has LM1875, LM1876, LM4766 and other familiar chips. Among them, LM4766 is the latest, which is designed for two channels and contains protection circuits such as overvoltage, undervoltage, overload, and overtemperature. Its output power is not less than 2 & TImes; 40W. The bass is deep and flexible, with a bold style.

3. TDA7294

TDA7294 is a very innovative DMOS high-power integrated circuit that was developed by the famous European SGS-THOMSON STMicroelectronics in the 1990s to mainland China. It sweeps the sound, cold and hard sounds of the linear amplifier and thick film integration in the past, and is widely used in the field of HI-FI: such as home theaters and active speakers.

The design of the chip is focused on sound, and has the advantages of bipolar signal processing circuit and power MOS. It has the characteristics of high pressure resistance, low noise, low distortion, and reproducible tone. The short circuit current and overheat protection function make its performance more perfect.

The main parameters of TDA7294: Vs (power supply voltage) = ± 10 ~ ± 40V; Io (peak output current) is 10 amps; Po (RMS continuous output power) is 70W at Vs = ± 35V, 8Ω, Vs = ± 27V, 70W at 4Ω; music power (effective value) Vs = ± 38V, 100W at 8Ω, 100W at Vs = ± 29V, 4Ω. The total harmonic distortion is extremely low, only 0.005%.

In addition, SGS-THOMSON STMicroelectronics has several representative power amplifier chips, such as: TDA7295, TDA7296, TDA7264, TDA2030A, etc.

Four, LM4610N

The LM4610 is a high-quality DC-controlled audio circuit from National Semiconductor Corporation. It is a stereo integrated circuit that uses DC voltage to control tone, volume and channel balance, and has 3D sound field processing and equal loudness compensation functions.

The circuit has smooth and smooth control, natural and smooth sound quality, clear high frequency and good resolution. The 3D surround sound field produced has a strong three-dimensional sense of space and surrounding. The subjective feeling is similar to the effect of SRS.

The main electrical parameters of LM4610N are as follows: with 3D sound field processing function and loudness compensation function. Loudness compensation is aimed at reducing the sensitivity of the human ear to high and low frequency signals when the volume is low. Therefore, at different volumes, the high and low frequency ends are appropriately boosted and compensated, so that the human ear always hears a flat and balanced response at any loudness.

Its voltage range is: 9V ~ 16V (typically 12V, current is 35mA); distortion is only 0.03%; signal to noise ratio is up to 80dB; bandwidth is up to 250kHz, volume adjustment is 75dB; balance adjustment is 1 ~ 20dB; tone adjustment range is ± 15dB; maximum gain is 2dB; LM4610N has the advantages of high input impedance (30Ω) and low output resistance (20Ω).

The LM6410N tone control circuit has a prominent role in improving sound quality and enhancing low-frequency strength and three-dimensional sense of space. It can be said that the LM4610N is an excellent product for assembling a power amplifier system or replacing a tuning part.

Five, digital super bass processor M51134P, M51134P

M51134P is a special subwoofer detection enhancement circuit specially developed by Mitsubishi Corporation for AV audio and video systems. Its internal includes: frequency detection, adjuster, level detection, low-pass filter VCA voltage control amplification, etc. The principle is to use digital filtering to detect the level of the low-frequency component in the input signal, strengthen the corresponding low-frequency component and perform low-frequency dynamic expansion (and the voltage-controlled amplifier is completed). The circuit is different.

The subwoofer effect provided by M51134P has a strong sense of shock, especially the thunder, gunfire, explosion and so on. The M51134P only detects signals below 120 Hz. If there is no component below 120 Hz in the input signal, there is no output.

Sixth, the latest standard virtual Dolby surround sound chip QS7779, QS7785

QS7779 / QS7785 is a single-chip virtualized surround sound processing circuit launched by Canada Qsound Audio Lab. It is currently recognized by the industry as a virtual Dolby surround chip with the processing effect closest to the natural sound! QS7779 is 2 in 2 out, QS7785 is 2 in 5 out, both include Dolby Pro Logic and DVD (AC-3) mixed signal decoder, using Qsound Lab ’s patented Qsurround virtual surround technology, and by Qsound laboratory is authorized to use.

The main functions of the chip are:

1. If the input is an ordinary stereo signal, the stereo effect is enhanced;

2. If the input is a 2-channel matrix coded signal (Dolby directional logic or mixed AC-3 signal), then decode it first, and then virtualize and synthesize a 2-channel or 5-channel output.

QS7779 main features:

1. It contains Dolby Pro Logic and DVD (AC-3) mixed signal decoder, and uses 2 speakers to realize virtual surround sound.

2. The signal-to-noise ratio is 11db and the dynamic range is 110db.

QS7785 main features:

1. The built-in Dolby directional logic and DVD (AC-3) mixed signal decoder, the surround signal solved is a 2-channel full frequency band, which is the same as AC-3 surround sound, which is better than Dolby directional logic system.

2. 3D stereo enhancement technology is used in the front, and 3D synthetic virtual surround technology is used in the rear. There are two enhancement methods (low enhancement and high enhancement), with center output and bass enhancement.

3. Use 5 channels to achieve surround sound, and 2 channels output mode is also available.

4. Signal-to-noise ratio 11db, dynamic range 110db

Seven, operational amplifier

We commonly have 4558 (commonly used for some Walkmans). NE5532 was once hailed as the emperor of operational amplifiers. AD712K / AD827 (very good shipping on the market, it is difficult to buy the original product, I heard that the order will have to wait for three months. The market price is about 100 yuan per block). The above are dual op amps, and there are four op amps such as: TL084, LT058 and so on.