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Switch to NJRC & MUSES Today and Discover a Whole New Level of Audio Clarity

With products ranging from the very high-end audio (MUSES Series) to the simple low cost voltage regulator, there is always an NJR product to suit your application's needs, including a range of RF Immunity operational amplifiers and regulators for situations where this is required - such as automotive or portable equipment.

MUSES03


DESIGNED WITHOUT COMPROMISE

The MUSES03 JFET input op-amp is the latest in the flagship series of components by NJRC. Low noise, high speed and with virtually no distortion (0.00003%), the MUSES03 is for premium audio gear. The MUSES series includes single and dual op-amps, a volume IC and SiC diodes.


NJM8XXX SERIES


DESIGNED WITHOUT COMPROMISE

By utilising the lessons learnt whilst designing the MUSES series, coupled with some unique RFI suppression circuitry, NJRC has released a series of cost effective op-amps that offer both superior sound quality and RFI immunity.

ULTRA LOW PHASE NOISE CRYSTAL OSCILLATOR IC


RFI RESILIENT OP-AMPS

The NJU6385U is a CMOS quartz crystal oscillator IC (20 ~ 50MHz) that realises exceptionally low phase noise. Consisting of an oscillation amplifier and a 3-state output buffer, this device has been designed for audio applications in which the lowest noise is of paramount importance.



Quick Op-amp Selector Guide

There are now thousands of different op-amps in production, so selecting one that meets your requirements at the right price can prove rather time consuming. To help guide you through the plethora of op-amps available, we have selected an essential range that will cover most applications, from budget to high end, and you can be sure that they offer great value and will be readily available for years to come.

If one of the op-amps featured below won’t do, then remember that Profusion has hundreds more to choose from, each one optimised for a different application.

Where to start?

The first decision to make when choosing the op-amp for an audio application is usually between bipolar and JFET input transistors, and for most audio circuits both perform equally well. JFET op-amps have high input impedances so voltage noise is higher, but current noise will be lower. CMOS is generally noisier but lower power, and there are many such designs appearing because CMOS production foundries are plentiful. However, CMOS transistors are not well matched and noise results from imperfections close to the silicon surface, therefore you should only start with CMOS if power consumption is your top priority.

For most audio applications, including active filters, ADC and DAC buffers, voltage followers, line drivers and receivers, the NJM8080 and NJM8065 are the first op-amps you should consider. Both are excellent “jelly bean” op-amps, meaning good all-round performance at a very low cost.

The NJM8065 is a much-improved 741 and is about the cheapest op-amp you can buy, so unless you need even better performance stick with this. For slightly better performance at the cost of higher power consumption, the NJM8080 is a good alternative.

For JFET inputs then, the NJM072C is the starting point. It’s a bang up-to-date 2015 version of the TL072 that was first introduced in 1976. If these op-amps don’t cut the mustard then follow the chart below for improved performance.




So what’s changed in the 50 years since the 741 was introduced?

In 1968 the µA741 was a sensation, as it offered state-of-the-art performance and spawned many new applications and circuit designs. The data sheet specifications are still respectable today, although you would not seriously consider it for new designs. Over that period there have been many advances in manufacturing technology, and circuit designs have both improved performance and/or lowered costs.

Comparing the 741 to the NJM8065 generic op-amp:


741NJM8065
Temp Range0°C to 70°C-40°C to +125°C
Supply Voltage Max36V36V
Supply Voltage Min20V8V
Supply Current Max3.3mA3.5mA
Offset Typical2mV0.5mV
Offset Max6mV3mV
Bias Current Max500nA 200nA
Offset Current Max200nA 50nA
En~60nV/√Hz5nV/√Hz
Slew Rate0.5V/µs4V/µs
fT1.2MHz10MHz
CMRR min70dB70dB
PSRR76dB76dB
Gain min86dB86dB
Max Output Current25mA80mA


The NJM8065 is a much-improved 741 and is about the cheapest op-amp you can buy, so unless you need even better performance stick with the NJM8065. Or the NJM8080, which is very similar and performs slightly better at the cost of higher power consumption.