概要

The JRC4558D is a dual operational amplifier integrated circuit (IC) produced by the Japan Radio Corporation (JRC), a company established in September 1959. The IC gained prominence in the late 1970s and early 1980s due to its affordability and acceptable audio performance, leading to its widespread use in Japanese electronic equipment, including iconic guitar pedals such as the Boss OD1 and the Tube Screamer. This extensive utilization linked the JRC4558D closely with the history of guitar pedal development and cemented its reputation among audio enthusiasts. In the mid-1980s, JRC transitioned to New Japan Radio Co. Ltd (NJM), moving production facilities to East Asia while continuing to manufacture the 4558 op-amps under the NJM4558D label. Despite changes in production equipment and facilities, the reissued NJM4558D maintained the same specifications as the original, although myths about differences in sound quality between the old and new chips persisted. Listening tests and technical analyses have generally shown no audible differences between the original JRC4558D and its reissued counterparts. The JRC4558D remains notable for its technical specifications, which include a wide operating voltage range, high DC voltage gain, and low input offset voltage, making it suitable for various applications, from audio amplification to precision instrumentation. Its design incorporates a high input impedance and low noise characteristics, making it a popular choice for high-fidelity audio equipment and other sensitive signal processing tasks. Despite its enduring popularity, the JRC4558D has been subject to controversy, particularly regarding perceived sound quality differences with other operational amplifiers like the TL072 and NE5532. Enthusiasts and audiophiles have debated its merits, with some preferring its warm, classic tone and others favoring the superior noise performance of alternative op-amps. Nevertheless, the JRC4558D’s legacy in audio electronics and its continued use in various applications underscore its significance and impact on the industry.

歴史

The JRC4558D is a dual operational amplifier IC produced by the Japan Radio Corporation (JRC), established in September 1959. The company started issuing millions of these chips from the late 1970s until the mid-1980s, and they appeared in a wide range of Japanese electronic equipment from this period

. Initially, the JRC4558D was chosen by Japanese design engineers primarily because it was one of the cheapest dual op-amps available with acceptable audio performance. This affordability led to its extensive use in various applications, including audio equipment and guitar pedals. Some of the most successful guitar effects like the Orange Squeezer, DOD YJM 30, Boss OD1, and the famous Tube Screamer incorporated the JRC4558D, linking the IC closely with the history of guitar pedal development. In the mid-1980s, JRC transitioned to New Japan Radio Co. Ltd (NJM) and moved their production facilities to East Asia. Despite the change in manufacturing plants and the introduction of new production equipment, NJM continued to produce the 4558 op-amps, now labeled as NJM4558D. A few years later, NJM began re-issuing the JRC4558D with a matte finish, although these reissued chips were not produced at the old plant. The specifications of the reissued chips remained the same as the original, yet a myth persisted regarding whether the reissue chips were as good as the originals. The JRC4558D’s popularity persisted over the years, particularly among enthusiasts who claim to notice differences in sound quality between chips from different manufacturers or even between identical JRC4558 chips from the same manufacturer. However, various factors such as components placement, values tolerance, circuit layout, soldering joints, temperature, and power supply can influence the sound more than the op-amp itself. Actual listening tests, oscilloscope traces, and spectrum analysis have shown no audible difference between today’s NJM4558D and the old ones. The legend of the JRC4558D also includes tales of NJM maintaining the original machinery used in the old JRC4558 manufacturing process, potentially able to produce the chip again if an order exceeds 50 million parts. Despite its age and supposed “low quality” status for audio applications, the JRC4558D remains a popular choice in many electronic circuits, continuing its legacy in the realm of audio equipment and beyond.

技術仕様

The JRC4558 is a dual operational amplifier known for its versatility and wide range of applications. It features a broad power supply range, allowing it to operate effectively in both single and dual supply configurations. Specifically, it can operate with a single supply voltage ranging from 3V to 20V or a dual supply voltage from ±1.5V to ±10V

. One of the key characteristics of the JRC4558 is its large DC voltage gain, which is rated at 100dB. This makes it suitable for applications requiring high gain accuracy. The output swing is another notable feature, ranging from 0V to VDD-1.5V. This operational amplifier also boasts a unity gain bandwidth of 2MHz and comes internally frequency compensated for unity gain, which simplifies the design process for users. Additionally, the JRC4558 has a low input offset voltage of just 1mV, making it ideal for precision applications. It is also RoHS compliant, which means it is lead-free and environmentally friendly. The JRC4558’s operational amplifiers are designed to be internally compensated and maintain consistent performance across a wide range of temperatures and operating conditions. The device tracks parameters over the specified temperature range and ensures phase and gain matching between its amplifiers. Moreover, the operational amplifiers within the JRC4558 exhibit low input noise, making them suitable for use in high-fidelity audio applications and sensitive signal processing. Its input stage provides a significant voltage gain of 100dB, although not as high as the infinite gain of an ideal op-amp. In terms of physical characteristics, the JRC4558 is available in both 8-pin SOP and DIP packages, making it versatile for different design requirements. The device can operate within a temperature range of 0°C to 70°C. The JRC4558 is compatible with industry-standard pin configurations, enabling it to be used interchangeably with other op-amps like the LM358 or MC1458. This makes it a cost-effective and reliable choice for a variety of applications, including amplification, filtering, and analog circuit design.

内部アーキテクチャ

The internal architecture of the JRC4558 IC is designed to deliver high performance and flexibility in a variety of electronic applications. This dual operational amplifier (op-amp) incorporates several critical components and stages that contribute to its effectiveness and versatility.

入力ステージ

The input stage of the JRC4558 op-amp consists of a Long-Tailed Pair (LTP) differential amplifier, complemented by a current mirror. This configuration includes transistors Q1, Q2, Q3, Q4, and Q5, along with resistors R1, R2, R3, and capacitor C1, all playing crucial roles in this stage

. The differential amplifier ensures high input impedance and good linearity, making the JRC4558 suitable for precise signal amplification.

電圧増幅段（VAS）

At the core of the JRC4558’s high-gain capabilities is the Voltage Amplifier Stage (VAS). This stage operates in class-A mode, which is characterized by low power consumption and minimal distortion. The VAS includes a common emitter amplifier with two NPN transistors, Q6 and Q10, arranged in a Darlington configuration. This setup significantly boosts the current gain. Additionally, the VAS utilizes the output of the current mirror Q7 as its collector load, further enhancing the gain

.

出力段

The output stage of the JRC4558 is designed to provide sufficient current gain to maintain the VAS voltage potential across the low-load output impedance. This stage operates as a Class AB push-pull emitter follower amplifier, ensuring efficient signal amplification with minimal distortion. Key components in this stage include the Vbe Multiplier, comprising transistors Q11 and Q12, and resistors R6, R7, and R8, which set the bias current for the output stage

. This design is pivotal for applications requiring robust current delivery and precise signal reproduction.

Compensation and Stability

The JRC4558 incorporates internal frequency compensation, which enhances its stability across a wide range of frequencies. This feature is crucial for maintaining consistent performance in various applications, from audio equipment to signal processing circuits

.

ピン構成

The JRC4558 IC features an 8-pin configuration that is standard in the industry, allowing for compatibility with a variety of other devices. The pins are designated for specific functions, including output terminals, inverting and non-inverting input terminals, and power supply connections. This configuration simplifies integration into complex circuits and supports a broad range of operational voltages

. The comprehensive architecture of the JRC4558, from its input and voltage amplifier stages to its output stage and frequency compensation, makes it a highly versatile and reliable component in numerous electronic applications.

Biasing Circuits

The biasing circuits within the JRC4558 IC play a critical role in ensuring optimal performance and stability of the operational amplifier. One such circuit, the Vbe Multiplier, also known as Bias Servo, Amplified Diode, Rubber Diode, or Rubber Zener, is utilized to mitigate crossover distortion and safeguard the output stage from thermal shutdown. This biasing block, which includes components Q8, Q9, and R4, is crucial for maintaining the proper functioning of the output transistors in a push-pull topology. In this configuration, transistors Q11 and Q12 require the input signal to surpass their forward voltage (Vbe, typically around ±0.6V) to commence conduction. To counteract this, the transistors are biased so their idling voltage remains above the forward voltage, ensuring continuous conduction and reducing distortion

. Another integral aspect of biasing in the JRC4558 is the current mirror. The current mirror, comprising high Hfe (β) differential dual transistors Q4 and Q5 with matched parameters, is thermally coupled within the same package to enhance performance. This configuration not only improves gain but also ensures signal integrity by equalizing the quiescent current in each side of the Long-Tailed Pair (LTP) differential amplifier, which significantly benefits linearity and Common Mode Rejection Ratio (CMRR) . In addition, output resistors R6, R7, and R8, often referred to as ballast resistors, are incorporated between the emitters of the output pair to promote better current sharing and minimize discrepancies due to internal emitter resistances. These resistors, typically of low value, enhance thermal stability, prevent direct loading between complementary transistors, and help maintain a steady quiescent current, thus contributing to the overall reliability of the amplifier . The VAS (Voltage Amplifier Stage) further drives the output stage, but it’s crucial to be mindful of variations in bias caused by temperature fluctuations or part variances, which can lead to potential crossover distortion and quiescent current instability. To ensure better performance, the output range of the JRC4558 is designed to be approximately 1.5 volts less than the supply voltage, primarily due to the Vbe characteristics of the output transistors, Q11 and Q12 .

パフォーマンス指標

The JRC4558 is a versatile operational amplifier (op-amp) known for its robust performance characteristics, making it a popular choice in various electronic applications.

スルー・レート

One of the critical performance metrics of the JRC4558 is its slew rate, which defines how quickly the output of the op-amp can change in response to changes in the input signal. Although specific slew rate values for the JRC4558 are not directly provided in the collected data, it is notable that op-amps with higher slew rates tend to produce less distortion in audio applications

. The TL072, for instance, is another op-amp that features a high slew rate of 20 V/μs, which enhances its performance in audio circuits by minimizing harmonic distortion and noise.

出力段

The JRC4558 includes a Class AB push-pull emitter follower amplifier in its output stage, designed to provide sufficient current gain and maintain voltage potential across low-load output impedance

. This design aims to mitigate crossover distortion and manage quiescent current fluctuations, which can affect performance. The output stage components include transistors Q11 and Q12, and resistors R6, R7, and R8, which serve as ballast resistors to ensure thermal stability and steady quiescent current.

Input Stage and VAS

The input stage of the JRC4558 consists of a Long-Tailed Pair (LTP) differential amplifier coupled with a current mirror, ensuring signal integrity and linearity

. This setup is critical for improving the Common Mode Rejection Ratio (CMRR) and achieving balanced currents through differential transistors. The Voltage Amplifier Stage (VAS), comprising a common emitter amplifier with a Darlington configuration, is essential for amplifying low amplitude input signals to higher levels while maintaining minimal power losses.

Noise and Offset Characteristics

The JRC4558 features low-noise input transistors, contributing to its suitability for audio and other sensitive applications

. In comparison, the TL072 offers low input bias and offset currents, along with a low noise level of 18 nV/√Hz at 1 kHz, and a low total harmonic distortion of 0.003% (typical), indicating that it is also designed to handle noise efficiently.

Compatibility and Reliability

The JRC4558 is known for its cost-effectiveness and industry-standard pin compatibility, making it a reliable choice for various commercial equipment and devices

. It shares compatibility with other ICs such as LM358, MC1458, and others, which adds to its versatility in different circuit designs.

アプリケーション

The JRC4558 IC is a versatile dual operational amplifier widely utilized in various analog circuits due to its high performance, low noise, and wide bandwidth characteristics.

Audio Amplification and Processing

JRC4558 is commonly integrated into audio circuits such as guitar pedals, amplifiers, equalizers, and preamplifiers. Its ability to provide high voltage gain and low current consumption makes it ideal for these purposes

. The IC is popular among guitar pedal makers for its high performance in such applications.

Signal Processing and Instrumentation

The IC is utilized in a range of signal processing applications, including instrumentation amplifiers and sensors

. It is also deployed in precision instruments where accurate amplification and high impedance are required. For instance, it finds use in automotive and ground-referenced signal amplification, hold and sample amplifier applications, and photocurrent instrumentation utilization.

Comparator and Differential Amplifiers

JRC4558 is frequently employed in comparator circuits and differential amplifiers, leveraging its dual-op-amp configuration to execute multiple functions simultaneously

. This IC is also involved in the calibration of analog voltage sensors within industries and current loop testing for troubleshooting communication line errors.

Timing and Oscillator Circuits

The IC is used in designing multivibrators or long-duration timers that can operate from microseconds to minutes and hours

. Additionally, it is implemented in oscillator circuits for signal generation.

Security and Consumer Electronics

JRC4558 finds applications in intrusion alarm systems, DVD players, recorders, and professional audio mixers due to its high reliability and cost-effectiveness

. Its usage extends to consumer and scientific devices, integrating into various portable and professional electronic equipment.

General-Purpose Op-Amps

Due to its industry-standard pin compatibility, the JRC4558 can be easily replaced with many substitute dual op-amp ICs like NE5532, LM158, and LM358

. Its versatility and performance make it a favorite among hobbyists and engineers for general-purpose op-amp circuits.

類似ICとの比較

The JRC4558D IC stands out in the realm of dual operational amplifiers due to its distinct features and performance characteristics, especially in audio applications. However, it is often compared with other operational amplifiers such as the TL072 and RC4559.

JRC4558D vs. TL072

Technology

The JRC4558D utilizes bipolar technology, which allows it to deliver robust performance in various electronic applications, particularly those involving audio processing

. On the other hand, the TL072 uses JFET (junction field-effect transistor) technology. This distinction influences several performance aspects of these ICs.

入力インピーダンス

The JRC4558D boasts an input impedance of approximately 5 megaohms, which is adequate for many applications but not as high as the TL072. Due to its JFET input technology, the TL072 offers increased input impedance, making it more suitable for high-impedance signal sources

.

Noise Performance

In terms of noise performance, the JRC4558D has moderate noise characteristics. It is well-regarded in audio applications for its balance of performance and cost-effectiveness. The TL072, however, is known for its low noise performance, making it a preferable choice in situations where minimal noise is critical

.

Speed and Voltage Handling

The TL072 exhibits enhanced speed and is better suited for handling higher input and output voltage levels compared to the JRC4558D. This makes the TL072 more appropriate for applications requiring faster response times and higher voltage ranges

.

JRC4558D vs. RC4559

The RC4559 is another common substitute for the JRC4558D. Both ICs share similar pin configurations, making them interchangeable in many circuits

. However, there are nuanced differences in their specifications and performance.

Voltage Gain and Slew Rate

Both the JRC4558D and the RC4559 offer high voltage gains, but the JRC4558D typically provides a voltage gain of up to 100 dB and a slew rate of about 1.7 V/µs. This makes it well-suited for applications requiring significant amplification with reasonable speed

.

Supply Voltage Range

The JRC4558D operates within a supply voltage range from ±5V to ±15V, offering flexibility in various circuit designs. The RC4559 also operates within similar voltage ranges, ensuring compatibility in most applications where the JRC4558D is used

.

Controversies and Criticisms

The JRC4558D integrated circuit has been subject to various controversies and criticisms within the audio electronics community, particularly among guitar pedal enthusiasts and audiophiles. One significant point of contention is the perceived difference in sound quality between the JRC4558D and other operational amplifiers (op-amps) such as the TL072 and NE5532.

Sound Quality Debate

A major criticism of the JRC4558D centers on its sound quality compared to other op-amps. Some users argue that the JRC4558D produces a “warm” and “classic” tone that is particularly favored in guitar pedals, while others believe it falls short in terms of noise performance and overall fidelity

. This debate is not merely academic but has practical implications for musicians and audio engineers who prioritize specific tonal characteristics in their equipment.

Comparisons with Other Op-Amps

The JRC4558D is often compared unfavorably with the TL072, which is known for its low noise characteristics and high input impedance

. Users who favor the TL072 argue that it offers superior audio performance, particularly in applications where minimizing noise is crucial. In contrast, the JRC4558D is sometimes criticized for its moderate noise performance, although some musicians may still prefer it for its distinctive tonal qualities.

Variability in Manufacturing

Another point of controversy involves the consistency of the JRC4558D across different manufacturing batches. There have been claims that newer versions of the JRC4558D, produced under different prefixes or manufacturing processes, do not match the sound quality of earlier versions

. This inconsistency can be problematic for those attempting to faithfully reproduce the sound of classic audio equipment or create high-quality clones of renowned devices.

Community Opinions

The audio electronics community remains divided on the merits and drawbacks of the JRC4558D. Some users, like LJ King, express a preference for replacing the JRC4558D with other op-amps such as the TL072, citing the latter’s better sound in specific applications

. On the other hand, there are those who staunchly defend the JRC4558D, emphasizing its role in achieving a particular sound signature that is irreplaceable in certain musical contexts.

レガシーとインパクト

The JRC4558 operational amplifier (op-amp) holds a distinguished place in the annals of audio electronics and instrumentation. Its widespread use in various iconic guitar pedals, including the Boss OD1, Tube Screamer, and the Orange Squeezer, underscores its historical significance in shaping the sound of modern music equipment

. Japanese engineers originally adopted the JRC4558 due to its cost-effectiveness and acceptable audio performance, leading to its ubiquitous presence in a multitude of audio devices. The versatility of the JRC4558 extends beyond music gear, finding applications in several fields. It has been instrumental in the development of hold and sample amplifiers, portable instrumentation, intrusion alarm systems, and photocurrent instrumentation. Its deployment in instrumentation amplifiers, long-duration timers, and function generators further exemplifies its adaptability and robustness in various electronic circuits. Despite its success, the JRC4558 has been the subject of debate among audiophiles and engineers. Some criticize its audio quality, deeming it inferior compared to other op-amps like the TL072, which is favored for its low noise and high-speed operation. Nevertheless, the JRC4558’s warm, classic sound continues to be cherished, particularly in overdrive circuits where its characteristics complement the desired tonal qualities. Moreover, the JRC4558’s impact on the evolution of audio electronics is evident in its continued comparison with other op-amps such as the NE5532. While the NE5532 is celebrated for its low distortion and high slew rate, the JRC4558 remains preferred for applications where low noise and high output capability are paramount. This ongoing comparison highlights the JRC4558’s enduring relevance and its ability to cater to specific audio needs.