Got some numbers for us?living sounds said:The new ones measured better in terms of THD in audio circuits.
Got some numbers for us?living sounds said:The new ones measured better in terms of THD in audio circuits.
We may be talking about the same thing. Wafer purity matters the smaller the feature size used for the tiny components inside the IC. Over the decades time span that we are talking about for this one part the number of small transistors that IC makers can fit on a single digital chip has increased exponentially. So acceptable surface impurities from decades ago would stop modern chips from working at all.ricardo said:Dunno whether its true today but certainly for LN, cleanliness is everything. It's all about sh*t in the chip.
The same Mullard Southampton factory made the Mullard BFW11, my old favourite FET for condensor mikes. No other maker's BFW11 was anywhere near its LN performance. Today, no BFW11 is a LN device.
The EVIL latching & solutions are investigated by Wayne at http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6&t=641ricardo said:Some of the uber OPAs have yucky stuff which isn't shown on the datasheets ... or even picked up by the gurus. eg LM4562 & its more expensive siblings have a nasty latching behaviour on single supply applications.
Actually, its been pretty informative. Most competent designers don't see the need for da uber OPAs for good reasons ... some of them listed here.jackies said:So this thread went off the topic, discussing opamps and cables and THD and latching...
Let's get back to the original question!
Which OEMs are actually using modern high performance opamps?
Obviously, we are talking about audio equipment manufacturers, video and other higher bandwidth applications by nature require something better than TL072.
This incompetent grovels before this list of luminaries.ruairioflaherty said:I know lots of designers using these newer parts in modern gear - Dave Collins at Manley in their newer designs, Leif Mases at Maselec, Bruno Putzeys for Hypex, and now Mola Mola, John Siau at Benchmark. All very smart guys.
ruairioflaherty said:I know lots of designers using these newer parts in modern gear - Dave Collins at Manley in their newer designs, Leif Mases at Maselec, Bruno Putzeys for Hypex, and now Mola Mola, John Siau at Benchmark. All very smart guys.
JohnRoberts said:As I recall the 553x was roughly 4.5nV/rt HZ. Modern high performance op amps are delivering 1nV/rt Hz noise levels. While I don't expect a usable 12 dB drop in noise floor, better is always better, especially for marketing to customers who barely understand specs and the like.
JR
audiomixer said:JohnRoberts said:As I recall the 553x was roughly 4.5nV/rt HZ. Modern high performance op amps are delivering 1nV/rt Hz noise levels. While I don't expect a usable 12 dB drop in noise floor, better is always better, especially for marketing to customers who barely understand specs and the like.
JR
while the AD797 as an example has a roughly four times lower voltage noise (0.9nV/rt Hz) is also has a roughly four times higher current noise.... that combination of respectable voltage noise and very decent current noise of the NE5534 / NE5532 is difficult to find - even in modern opamps.
- Michael
It's time we jazz up modern design and create an entirely new industry based on NOS OPAs.JohnRoberts said:The 553x remains a respectable performer today, but it may be an uphill struggle to convince customers that any op amp older than they are belongs in a modern SOTA design.
ricardo said:It's time we jazz up modern design and create an entirely new industry based on NOS OPAs.JohnRoberts said:The 553x remains a respectable performer today, but it may be an uphill struggle to convince customers that any op amp older than they are belongs in a modern SOTA design.
The best OPAs have always been NOS Mullard NE5532/4s hand built from solid Unobtainium by Southampton virgins. They have a clarity, definition & sweetness unavailable in modern stuff and were of course used in the last of the great analogue mixing desks of the 80s & 90s. Sorry Mr. Groner 8)
Why should da tubophools have all the fun.
thermionic said:Hi Micheal,
The oscillation was seen by connecting a probe to the o/p socket, with the i/p socket shorted. My audio analyser picked up broadband fuzz at around -50-ish. I then hooked the scope probe and saw 18mV of something sine-shaped at 18Mhz.
The layout is on stripboard! The next stage is to give it to the PCB designer I work with. It seems daft to prototype anything with a 'relatively' quick opamp such as the 4562 on strip-board, but you have to get proof of concept somewhere, right? With anything faster I suspect you'd have to go for a multi-layer PCB from the start. Just the inductance of an IC socket can set off some OAs.
edit - trust me, you don't need to see the layouts. The moral of the story is that just a couple of mm here and there can trigger bad behaviour if the OA is quite fast.
Trying to prototype on a solderless breadboard with LME49990 and OPA1612 is a time consuming process!
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