Fullscreen HTML5Med Res (??MB)HTML4

The end of the venerable NE5532 could be used, minimising their thermal noise contribution. Of course, there were places where discrete transistors still ruled; for example, in circuits that needed to run from higher supply rails than the generous ±22V limit of the NE553x series. Still, in a lot of cases, the size and component count could be seriously reduced compared to discrete transistors (and possibly the cost as well) with little to no loss in performance. Fast forward to today There are hundreds of different op amps available, but the NE5532 (initially released in 1979) is ‘the classic’ audio op amp. It was such a good design that it is still widely used today, 55+ years later. That may be finally changing; unfortunately, not voluntarily. By Nicholas Vinen Various NE5532 variants and derivatives. From left-to-right, top-to-bottom: an original 1977 TDA1034, Signetics NE5534A, a couple of older TI NE5534As, a Signetics ceramic NE5532, a Signetics plastic DIP part, a couple of older TI NE5532s and a JRC SIL NJM2114L. Source: Jacob Rothman. I t is not surprising that a 1970s IC design may become obsolete in 2026. However, the way it is happening is far from satisfactory, and there are some real pitfalls for users. You may be wondering: why do we care so much about this part? Aren’t there better options? Well, yes... and no. There are good reasons why we’ll be genuinely sad to see it go. When it was released in November 1979, the NE5532 (and related NE5534) was revolutionary. IC op amps had been around for a while by then; the classic μa741 was released in 1968. If you wanted to build a hifi audio circuit in the early-to-mid 1970s, you’d use discrete transistors, as they 98 Silicon Chip could give much better performance. That was especially true for record player preamps that needed a lot of gain (about 100 times, more at low frequencies). That pretty much ended with the introduction of the NE553x series by Signetics. Finally, an op amp had performance that rivalled discrete transistors. They had extremely low noise – around 4-5nV/√Hz – making them good enough for use in phono preamp stages. They also gave extremely low distortion, ≤0.0004% THD+N across most of the audio band at moderate gains. The NE5532’s party trick was its ability to drive 600W loads with virtually no degradation in performance. That meant that low-value resistors Australia's electronics magazine The situation is clearly a lot different now than it was back then. We have many different high-performance op amps to choose from, including JFET and CMOS input types, railto-rail types, wide-bandwidth types, low-voltage types and so on. There are clearly applications now where other op amps, like those from Texas Instruments’ OPAxxxx series, are superior. That might be a battery-­ powered circuit, where the op amp needs to run from a supply voltage where the NE5532 wouldn’t work well, with a rail-to-rail swing to maximise signal handling. Or where even lower noise is required, or high-­ impedance inputs. As with anything, though, there are trade-offs. There are disadvantages to these fancy new op amps. Most of them are not available in DIP; it’s an SMD package (eg, SOIC-8) or nothing. Also, over time, the NE5532 became incredibly cheap; for much of the last decade, it cost under 50¢ per piece, even in smaller quantities. Some of the new, better op amps are not too dear (say $1-2 each), but others can be $5 or more. $2 per dual op amp isn’t so bad when you need one, but if you’re designing a device with many op amps, the cost can add up quickly! So if you wanted a high-­performance DIP op amp, until recently, the NE5532 was usually the best choice. The LM833 is sometimes a good alternative, but it’s best for driving 1kW+ loads and is limited to ±18V supply rails, so often the NE5532 was a better choice. The LM833 also usually costs a bit more. In addition, many of the new ‘whizzbang’ op amps can be a lot more ‘fussy’ in use. They require quieter supplies, better bypassing, and better layouts (keeping magnetic loops small). Otherwise, they could oscillate, leading to high distortion – exactly the sort of siliconchip.com.au thing you’re trying to avoid with an expensive op amp. In contrast, the NE5532 generally performs well with a single 100nF bypass capacitor. As long as the PCB layout isn’t terrible, you usually won’t have any problems with it. In other words, it’s a forgiving part to use in your designs. This is probably one reason these new parts are not available in dual inline packages; lead and trace inductance would make proper supply bypassing very difficult. Besides, these days, most manufacturers (the customers buying these parts in volume) prefer SMD packages for easier, cheaper assembly and better board density. The result of all this is that, for a long time, the NE5532 was a safe choice. Not any more, unfortunately... What happened? Signetics was acquired by Philips in 1975, and the brand was subsequently phased out. The NE5532 continued to be manufactured by other companies such as Texas Instruments (TI) and National Semiconductor (NS). TI bought NS in 2011, leaving them as (almost) the sole manufacturer of the NE553x. The exception was (and is) onsemi, who still makes the SMDonly NE5532D. However, in December 2025, TI released a new “RevK” data sheet for the NE5532 with significantly degraded specifications, as shown in Table 1. This was apparently spotted by diyAudio forum member diyralf in February this year – see siliconchip. au/link/accj We were informed of this change by Practical Electronics contributor Jacob Rothman this May. We had heard rumours of problems with NE5532s made by TI, even before December 2025, but we hadn’t realised what was going on until Jacob wrote about this topic in the July 2026 issue of Practical Electronics magazine, for his Audio Out column. After all, who expects a part that has been in production for 50+ years, with pretty consistent performance during that time, to suddenly change? Surely a reputable manufacturer wouldn’t silently replace it with an inferior version – would they? There’s some good news here – the ‘new version’ of the NE5532 has slightly more bandwidth and slightly lower current consumption. But the siliconchip.com.au Fig.1: total harmonic distortion plus noise (THD+N) versus frequency for the old (RevJ data sheet) and new (RevK) NE5532 ICs by Jacob Rothman. Note that this is in a reasonably ‘challenging’ circuit; the results will be more similar for something like a simple unity-gain buffer. bad news is much worse. The maximum slew rate is almost halved, leading to higher measured distortion in our tests. Critically, with the maximum supply voltage reduced to ±18V, in circuits that ran the NE5532s at (say) ±20V – within the old specification! – these new parts will now go up in a puff of smoke. This has been verified – it isn’t that they might fail at ±20V, they will fail. Bizarrely, the internal circuit structure has changed so much that the input transistors, which were NPN types in the original NE5532 and subsequent versions, have now become PNP. In circuits where the input transistor polarity matters (which is not uncommon), they won’t work correctly either. Frankly, it’s hard to see how it’s possible to sell these parts under the same code. That’s the real problem; those Table 1 – NE5532 RevJ vs RevK Specification RevJ RevK Bandwidth 10MHz 12MHz Slew rate 9V/μs 5V/μs Distortion Very low Higher Max. voltage ±22V ±18V Rec. voltage ±20V ±15V Supply current 8mA 6mA Input transistors NPN PNP Input clamp diodes? Yes No Australia's electronics magazine who are unaware of this change might buy the new parts thinking, quite reasonably, that they’re a drop-in replacement for the old ones with unchanged performance. They aren’t. For example, our Compact Hifi Headphone Amp (December 2024 & January 2025; siliconchip.au/ Series/432) uses NE5532 op amps and we provide distortion plots and other performance specifications. So you’d expect that if you build our circuit using the specified parts, you will get a device with very close to the same performance. However, if you use these new NE5532s, that is not guaranteed. There may not even be a good way to tell which version you receive, although it probably won’t be long before all the old stock is out of the system and the new/worse device is all you’ll get. Another change to the design is that for most of the life, the NE5532 had ESD protection/clamp diodes on its inputs. The new design apparently lacks these, and the data sheet reflects this by halving the ESD protection rating from 2kV to 1kV under standard test conditions. Any circuit design that relied on these clamp diodes for protection or otherwise can’t use the new version. All these changes mean that not only are they not fully compatible, they also don’t result in the same performance – see Fig.1. We suspect that the new, lower-power version struggles to drive the same low load impedances the old one could. What about the NE5534? The NE5534 is, effectively, a single version of the dual NE5532. There are some differences; for example, the NE5534 is not unity-gain stable without an external compensation capacitor, and the NE5534 has a lower noise specification, but otherwise, they have a similar design and performance. There’s no evidence currently that the NE5534 will face the same fate as the NE5532. Still, given how the NE5532 change came as a surprise, we would not assume it won’t happen. Therefore, we plan to stock up on those parts as well, just in case, for those applications where they are worth using (or for boards already designed for the single part). A silver lining New Japan Radio (NJR) is another source of the NE5532, but they call August 2026  99 Table 2 – selection of alternative high-performance dual op amps Device Supply Input type Noise Bandwidth Distortion Package Rail-to-rail? Cost NE5532 (old) ±5-22V NPN NJM5532D ±5-22V NPN 5nV/√Hz 10MHz ~0.0003% DIP/SOIC No 40¢ 5nV/√Hz 10MHz ~0.0003% DIP/SOIC No $2+ NE5532 (onsemi) ±5-22V* NPN 5nV/√Hz 10MHz ~0.0003% SOIC No $1.50 NE5534 (single) ±5-22V NPN 3.5nV/√Hz 10MHz ~0.0003% DIP/SOIC No $1.30 NE5532 (new) ±5-18V PNP 5nV/√Hz 12MHz ~0.001% DIP/SOIC No 40¢ LM833 ±5-18V PNP 4.5nV/√Hz 15MHz ~0.0003% DIP/SOIC No 40¢ NJM4580D ±2-18V PNP 3nV/√Hz 15MHz 0.0005% DIP/SOIC No $1.10 OPA1602 ±2.25-18V NPN 2.5nV/√Hz 35MHz 0.00003% SOIC Output only $3.50 OPA1612 ±2.25-18V NPN 1.1nV/√Hz 40MHz 0.000015% SOIC Output only $8.30 OPA1642 ±2.25-18V JFET 5.1nV/√Hz 11MHz 0.00005% SOIC Output only $2.50 OPA1656 ±2.25-18V JFET 2.9nV/√Hz 53MHz 0.00003% SOIC Output only $1.40 OPA1679 ±2.25-18V JFET 4.5nV/√Hz 16MHz 0.0001% SOIC Output only $3.25 OPA1692 ±1.75-18V NPN 4.2nV/√Hz 16MHz 0.000045% SOIC Output only $2.20 OPA2210 ±2.25-18V NPN 2.2nV/√Hz 18MHz 0.000025% SOIC Output only $5.50 * recommended limit ±20V for thermal reasons their version the NJM5532. NJR was acquired by Nisshinbo in 2021, so its parts are now sold under that brand. According to the data sheet, its performance is an exact match to the chip we have become accustomed to. The good news is that they are still in production, including in dual in-line packages (DIP). The bad news is that they don’t plan to keep making them forever; at least, not in DIP. But they say they will continue for a few more years. At the time of writing, DigiKey has 47,167 NJM5532Ds in stock, while Mouser has 2268. Other vendors worldwide will also have some of these. For the convenience of Silicon Chip readers, and in case those are all sold out quickly, we will also have a reasonable stock of NJM5532Ds, the lower-­ noise version (NJM5532DD) and original NE5534s (the single channel version; the new versions may eventually have the same problems as the new NE5532s). In the UK, Jacob Rothman’s AOShop will also have numerous NE5532Ds and NJM5532Ds available for Practical Electronics readers. Most shops will still sell NE5532s and NE5534s, but you may not know which type you’re going to get when you order them, so we think using the NJM versions will be safer if you need guaranteed performance. Another op amp available in DIP that might be a good choice for circuits designed for the NE5532 or NJM5532D 100 Silicon Chip is the NJM4580D. This part has lower noise (3nV/√Hz compared to 5nV/√Hz) but is only rated for absolute maximum supply rails of ±18V, so it’s better suited to applications using lower supply voltages like ±15V. Still, it is available and its price is reasonable. Newer op amps As we mentioned earlier, there are better op amps than the NE5532 available, but almost all of them are SMDonly. Table 2 summarises some of the better options. Conclusion There are plenty of high-performance op amps available at the moment, but the NE5532/NJM5532D remains an excellent choice for mains-powered equipment, with its low cost, low noise, low distortion, high supply voltage capability and ease of use. It’s also one of the last good choices that’s available in through-hole (DIP) packages. It would be a pity if we couldn’t use this part anymore because it has been ‘dumbed down’. The disappointing part is not so much that these nearly 50-year-old parts are being discontinued; it’s that, if we hadn’t found out they were being replaced with an inferior version, we might have kept using them and wondering why our circuits didn’t work as well any more! If you have one of these parts and aren’t sure which version it is, apply a suitable supply voltage and check the current draw. If it’s less than 7mA, it’s likely the newer version; if it’s more than 8mA, it’s probably the older type. If you’re happy to use an SOIC part, the onsemi NE5532 remains a fine choice, but it’s much more expensive than the TI parts. At that price, you might consider something like the OPA1656 instead, unless you need the high supply rail voltage support. Or, if the output loading is not too severe, you could use the LM833, at a similar cost to the NE5532. If you must have the same performance as the good old NE5532 in DIP, the NJM5532D (or even better, DD) is a fine choice, but at a higher cost. SC Fake NE5532s from AliExpress. They’re some other kind of dual op amp with the markings ground off and NE5532 etched instead. Australia's electronics magazine siliconchip.com.au