Is there any new product there or just a re-badging of existing parts? I had a quick look, seemed to me to be just another marketing exercise but I could be just a tad too cynical?
Nothing new, as far as I know. The OPA1656 isn't even on that list yet. Several of those op-amps were already discussed on this thread, too
. I don't think it's rebadging as much as selection and branding. The OPA1611 has been a rebadged OPA211 since inception, probably true for a few of the others too, but the page is just a curation I think.
I think my use of 're-badging' was a misnomer but I couldn't come up with a more apt term. By 'badge' I wasn't referring to the device marking numbers. 'Re-categorization' seemed not exactly what they were doing as the categories themselves (premier, etc.) I don't think existed before. Perhaps 're-branding' would be better, or even just 'branding'....
Yeah I understood what you were getting at I think, and you're not wrong, it's definitely a marketing exercise.
Never use FETs in audio! They tend to have more THD than bipolar. Accurate measurements confirm that for years. FETs have their domain in microchips devices.
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Where do you come up with this stuff? FETs, both JFETs and MOS have their places.
http://www.ti.com/lit/ds/symlink/opa1656.pdf
http://www.ti.com/lit/ds/symlink/opa828.pdf
Don't bother! It's called religious fervor.Some of us don't like to pay for the whiskey...so it must be replaced with something else.
In this thread the stacked AD844 was far better in the Cary 303/200 than the OPA627 for I/V, but the OPA627 was the best as the output buffer
Using the AD844 as an I/V
Cheers George
What about the LM4562? I was going to order some for general-use stuff but they do look to be rather nice-
LM4562NA/NOPB Texas Instruments | Integrated Circuits (ICs) | DigiKey
$1.64 each too
LM4562NA/NOPB Texas Instruments | Integrated Circuits (ICs) | DigiKey
$1.64 each too
ESS uses OPA1612 for I/V for ES9038PRO evaluation board.
AKM uses OPA1612 for I/V for AK4499 evaluation board.
OPA1612 likes very low impedance power rails at HF (maybe too low for AD797) to sound its best, IME.
For older dac chips that output big clock transients, other opamps might be a better choice, don't know.
AKM uses OPA1612 for I/V for AK4499 evaluation board.
OPA1612 likes very low impedance power rails at HF (maybe too low for AD797) to sound its best, IME.
For older dac chips that output big clock transients, other opamps might be a better choice, don't know.
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The data sheet shows they can be unstable if larger bypass caps have too little ESR. It suggests putting a few ohms in series with some caps. They aren't kidding, IME.
A more more or less equivalent problem can arise if the rails are too low ESR at HF. People have seen the problem trying to use AD797 as the error amp in a Jung-Didden regulator, for one example. People have struggled trying to get them to work stably there.
An experiment adding several uf of film caps filtering the +-15v rails at power entry on a dac board several inches away from AD797 also provoked instability. Made OPA1612 sound much better though. Since I was more interested in chasing down other things I wanted to understand better, I just left the film caps there and swapped out the AD797 pair for a single OPA1612 in that particular location.
I think you mean undamped or under-damped. There’s no such thing as too low.
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*They're binned differently for offset. And a few of them like the OPA2209 vs the OPA1602 are almost identical but not quite (different input BJT's in that case). So it's mostly true, with a few exceptions.
Most likely, but don't know the exact internal mechanism that causes the problem. Besides, since there are always poles at some high frequency, as a practical matter too low will eventually amount to the same thing as undamped or under-damped.
Since you don’t understand the mechanism, your warning should be to avoid the bad practice of throwing lots of film caps at power rails.
Clearly it’s not unstable with the low output Z of a regulator.
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