I had the original Signetics and I assure you it was a different chip in same application than the ST and the like we get today, both in offset, noise and tone.
bingo! that's exactly what we do here..major hit & miss, but we're never outgunned
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I have heard this info from a few people. The 5532 seems to be made by many companies however, many suggest they are just not the same as the original units. I cannot comment that as I have never heard the Signetics models only the generic units you find these days.
Well that's all true if you judge everything with the meter of your scientific reason!
You see, you choose your own parameter of judgment, "measurable", that belongs to the same cathegory of thought & activity you're trying to legitimate, not only, to place as high as "the highest achivement of man". It's a petition of principle (as we call it in Italian)! You seem to be unable to look at science from the outside.
As someone put it (don't remember if it maybe was Baudelaire...ouch), limiting man's knowledge to its rational side is halving man's possibilities of knowledge... and thus of progress. And I would add that exasperating the rational side of man (science, technology...) is simply going backwards in the way of civilization, as of today.
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Well that's all true if you judge everything with the meter of your scientific reason!
My original complaint - an op-amp having "no bass". A statement of a physical, measurable reality. Let's forget all the THD, slew rate, etc. stuff. The statement that, for instance, a gain of 10 non-inverting line stage will move my woofer less by swapping op-amps, is absurd.
But... lowest THD (even at high frequency) is the most reliable parameter for predicting an opamp's sound quality I've met with so far. If someone can suggest a more significant one...I'll listen
If that were so we would all be listening to Japanese amps of the 80's and 90's with super low THD.
Hi Mooly,
I did ask leeperry for a more fact based, technical reason for his statements but I see he doesn't have one, just more smoke.
Pull one out, stick another in without any regard for other elements in the circuit (and no understanding of the circuit itself apparently) and do a subjective listening "evaluation" on it.
I sure wouldn't like to be the print or socket on whatever is getting all these devices tested out on
On a more serious note your absolutely correct, you can't evaluate like this, with not even the simplest measurements to back things up.
But it's interesting hearing all you folks comments
well, LME49722MA has some crazily low THD rate...and it's quite unbearable..723/725 that are said to be a lot more interesting to listen to carry 10x higher THD figures.
and CMRR/PSRR are also very important I think..when they're 60dB who cares about these parts?
my soundcard comes in two versions:
cheap=fairchild 5532 : 10MHz GBW/9V slew rate (Bipolar Input)
deluxe=OPA2132PA : 8 Mhz/20V (fet)
and I'm currently using a 12.5Mhz/4.5V (voltage feedback) part..and it sounds great, nasty..eh?
I might try a 5.6Mhz/3.9V JFET op-amp anytime soon.
and CMRR/PSRR are also very important I think..when they're 60dB who cares about these parts?
my soundcard comes in two versions:
cheap=fairchild 5532 : 10MHz GBW/9V slew rate (Bipolar Input)
deluxe=OPA2132PA : 8 Mhz/20V (fet)
and I'm currently using a 12.5Mhz/4.5V (voltage feedback) part..and it sounds great, nasty..eh?
I might try a 5.6Mhz/3.9V JFET op-amp anytime soon.
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Well that's all true if you judge everything with the meter of your scientific reason!
You see, you choose your own parameter of judgment, "measurable", that belongs to the same cathegory of thought & activity you're trying to legitimate, not only, to place as high as "the highest achivement of man". It's a petition of principle (as we call it in Italian)! You seem to be unable to look at science from the outside.
As someone put it (don't remember if it maybe was Baudelaire...ouch), limiting man's knowledge to its rational side is halving man's possibilities of knowledge... and thus of progress. And I would add that exasperating the rational side of man (science, technology...) is simply going backwards in the way of civilization, as of today.
Yes, I always pose a possibly plausible argument only against a reference system. But I can always talk relatively too. I can accept any subjective discussion for instance that says: ''We have the same DAC project, same phones amp, and phones. We exchange op amps without any other changes in that position, and we hear this and that. To the measure we agree by majority, we single out 2-3 op amps for this and that sonic reason for this argument in this situation only. Elsewhere maybe we would agree differently''. That is again a reference system although with enough considerations and relatives. Still has a base agreement. I.e. We do not generalize, we don't tweak technically further, but we look for subjectively best, fast checked out op amp solution, for a given situation.
I'm talking of another matter: chip opamps, which all (especially those for audio) have a similar amount of negative feedback. So the amount of negative feedback being rather constant, lower THD tends to be better. I believe. Of course when the difference is between 0.0001% and 0.00003% every difference becomes more spiritual than real
Sure, I like things like the LT1363 which has a lower open loop gain than all the audio opamps, thus a higher THD rating than the current champions.
The AD8599 should be another good instance.BTW, yes, I agree, not even THD is a reliable parameter to esteem sound quality on paper... There are super low THD opamps that sound awesome (LT1028 for one), and others that sound much less irresistible (e.g. LM4562, but also the OPA211 or OPA827 for my ears).
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Ha ha sure but they don't specify that side of things in datasheets
That is what our ears are for...
...and the reason why I prefer, say, the LT1028 to the OPA211
Harsh, the AD843? Tried in my DAC and my CMOY and it was nothing harsh in both. Actually, quite nice. Numbers guide the pairings as usual, though, and actually it wasn't the best match with the CS4398. And what's remained inside my CMOY is the more neutral and less 'boomy' AD845KN.majkel from head-fi said:
OPA637? Don't know.
The OPA627 is lifeless and very "hi-fi" in the worst sense, for my ears. Also unpleasantly dry in its midrange and lower treble. Give a try to the OPA132UA majkel.
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The AD845 when correctly deployed is a favourite of mine too, but once again you are just swapping devices randomly in different pieces of equipment.
I don't doubt for a moment that you hear differences but these "results" of yours are almost certainly non repeatable.
Change the equipment you are using and you will probably come up with another set of "favourites"
I don't doubt for a moment that you hear differences but these "results" of yours are almost certainly non repeatable.
Change the equipment you are using and you will probably come up with another set of "favourites"
Mr. Wurcer, you should have learn by now that these guys aren't engineers and they won't either put up in a contests and bet money on their statements. You can't win this debate in other words.
My personal statement here is when I tested uA741 in a phono amp it sounded not good. A NE5534 sounded a lot better and a possible slight improvement was achieved with a LT1115.
When I designed a headphone amp I tested OPA134, AD8610 and OPA627, all sounded good but I have no clue what the difference was between those.
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The AD845 when correctly deployed is a favourite of mine too, but once again you are just swapping devices randomly in different pieces of equipment.
I don't doubt for a moment that you hear differences but these "results" of yours are almost certainly non repeatable.
Change the equipment you are using and you will probably come up with another set of "favourites"
You don't get it... the AD845 is quite nice for driving headphones directly (definitely a peculiar application). So I keep it inside my 24V "evolved" cmoy (that takes fast bipolars too). I've preferred it even to the theoretically better suited AD8397.
Nothing to do with the LT1028, which is the most transparent thing I've heard -in line level applications-. It sounds so even in the cmoy... but it clips far too soon
I'm saying exactly what you are saying...am I not?