I thought everyone just bought the 5534A and ignored the 5534, since the A version is individually noise tested, whereas the 5534 is like buying 1/2 a 5532 for more money...
Device noise is nothing to do with screening, its the gain, surface and volume defect density in the input transistors that matters for this.
The dies are definitely different as I think they were laid out by hand back then?!?, the compensation caps are often the largest part of an opamp die so changing those affects the layout anyway.
I vaguely recall there was a 5532A once, but I think it died out? Anyway its not very efficient to screen multiple opamps for noise as you have to reject the whole die if any of the opamps is duff. Certainly not doable for quad opamps....
[ Ah yes, it still exists, it is the 5532 with guaranteed noise performance, so they do test them... I suspect when it really matters people just switch to the 5534A anyway. ]
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G'day Mark
I was led to believe the 5534AN was actually two channels, or at least two input sections run in parallel to reduce noise. I can't find any datasheets on them now, but I have a few dozen of them in my collection.
That's fine IF you have the choice----sometimes the 'A' version is not available from the brand you prefer. For a line-level circuit (where the difference in opamp noise is meaningless), I'd rather have a non-'A' version of a Philips/Signetics 5534 than a T.I. 'A' version.
If you don't need the low noise NE5532's are several times cheaper per opamp which is why you normally use them for line level and filter circuits rather than the 5534, besides unity-gain stability is normally required for line level
I believe the 5533 is a quad opamp, four channels.
If you want to sell a few let me know.
For all I know Hypex uses them in nCores, which were the best regarded class D amps untill Purify came up with something that might be even better.No way the TL072 is a serious audio OpAmp...
I have used OPA2604 afther a DAC and, true, it sounded better than regular jellybean OpAmps.
But LM4562 was even better - at least to my ears
So in what sense is this not a serious audio opamp?
On a further note: it is very difficult to design a circuit where performance is limited by the opamp. In other words, virtually all audio gear measures identically with a wide array of opamps. Any gear which is designed to a level where opamps matter typically uses the right opamps.
At the same time I am trying to teach my dog to roll, I am trying to convince my fellow audio friends not to. And certainly when a ne5532 is concerned. It is a great opamp for audio and everything you listen to has been tainted by its sound anyways.
SoNic_real_one said: No way the TL072 is a serious audio OpAmp...
vacuphile[/USER]: So in what sense is this not a serious audio opamp?
You must be joking, or trolling....... the TL 072 is noisy (18nV√Hz voltage noise), distorted (-90 db THD), and has difficulty driving loads below 10KΩ. Virtually any new opamp can trump this POS by an order of magnitude......vacuphile: virtually all audio gear measures identically with a wide array of opamps."
I HIGHLY doubt that to be the case, and they certainly don't SOUND the same!
This is complete nonsense when noise is the measurement in question. You think an audio console based on NE5532 will measure the same noise-wise if those chips are swapped out for TL072s?
