I usually use video op amps for my line stages. We also found that the LT1361 series was pretty good too. I have never seen why slew rates over 50V/us for preamps was necessary. Still don't.
One of the advantages of ICs, is you can swap them instant, using a support. See what it means ?
I don't know if slew rate is the reason, or Current feedback, (i have a little idea on this question) but, on my side, they had won all the contests we made.
High dynamic, high level of details, fluid trebles, sharp basses. Just instruments playing naturally with nothing but space between them, easy to separate, easy to listen. The signature is so different from a record to an other that i cannot find any due to the ICs. Contrary to some like NE5532 or high bandwidth voltage feedback ones like the Linear you refer to.
Don't think, don't suppose, just try.
I'm so satisfied with my old Rotel preamp, since it is equipped with such ICs than i would not change-it for any blowtorch in the world. As simple than that.
You are allowed to add a (fast) class A current stage in the feedback loop if you want to drive heavy loads in a professional way.
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Not really, several projects on here alone have tested such in great detail, such as OPC's 'the wire' series of amps. the amps ranged from headphone amps, right through 15WPC amps, to 250WPC poweramps. These amps were put through the ringer, there is nothing there of concern.
Why is it that people in your position often feel the need to guess at fantastic reasons why there is a fabled technical advantage, to lend weight to your personal taste/opinion? you would maintain much better credibility if you just rested on your preferences.
I cant believe you bought the MUSE marketing, as mentioned, the specs are rather ordinary across the board, some are downright bad compared to $2.50 chips. the low production runs of the OFC copper leadframes and magic marketing are the sole reasons for the price. haha OFC copper leadframe, thats really useful when plugging into an IC adapter or PCB, I guess those few mm of OFC make all the difference?
Why is it that people in your position often feel the need to guess at fantastic reasons why there is a fabled technical advantage, to lend weight to your personal taste/opinion? you would maintain much better credibility if you just rested on your preferences.
I cant believe you bought the MUSE marketing, as mentioned, the specs are rather ordinary across the board, some are downright bad compared to $2.50 chips. the low production runs of the OFC copper leadframes and magic marketing are the sole reasons for the price. haha OFC copper leadframe, thats really useful when plugging into an IC adapter or PCB, I guess those few mm of OFC make all the difference?
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Years ago, I found this one, ADA4899, and thought it would probably do a good job - I note that it's been mentioned a few times in a positive light at diyAudio.
After all, an order of distortion of -120dB at 1Mhz is not to be sneezed at ... 😉
Frank
After all, an order of distortion of -120dB at 1Mhz is not to be sneezed at ... 😉
Frank
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If a repetitive signal generates random output this could happen. However generating random outputs would render most electronic systems useless for anything but generating noise. Repetitive signals will generate predictable artifacts unless there is some really unidentifiable mechanism at play that only affects music like patterns.
FFT's using available audio ADC's can easily see noise and artifacts lower than -140 dB FS. The chances of a transducer even reacting to such a small signal seems far fetched. Even electrostatic transducers have enough internal friction as to probably not move with such a small signal.
I would go back to my earlier question about time frame for measurements. Its far more likely that resistor values change during musically significant periods due to to heating than harmonics and noises below -100 dB FS are audible. And I even think the resistor tempco's may be too small to be significant but its something I have not seen tested. (Read the ADI article on resistors to better understand what I'm talking about.)
Yes, that's absolutely correct. Let's add that we speak about narrow-band analysis resolution, not integral noise over whole 20Hz - 20kHz band.
Yes but only that low in the narrow bandwidth of an FFT bin which is typically these days 3Hz or lower. Spotting a relatively broadband noise floor shift of a dB or so isn't at all easy on an FFT. Or at least, as far as I'm aware it isn't - I could have missed out on some new techniques 😛
@PMA - its 'and FFT is poorly understood' 😀 Brings to mind James Keiser's saying.
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Above 200 Hz or so Vinyl actually is better than the CD´s 96dB...
Rumpelspektrum - AUDIO
The red trace is with a vinyl record.
This was already explained to you, very carefully, a few hundred posts back, when you were pontificating (incorrectly) about inherent 7th order distortion in ICs. Perhaps you might wish to review.
Helpful Attitudes...
It wouldn't hurt to re-explain it for those who missed it, would it Stuart ?.
Thanks, Dan.
Or give a post reference ?.
It wouldn't hurt to re-explain it for those who missed it, would it Stuart ?.
Thanks, Dan.
Or give a post reference ?.
Try using the "search this thread" option if you're interested. That's all I'd do anyway- I don't keep post numbers memorized. The discussion spanned perhaps a dozen posts. Even better, google "groner opamps" and read his paper yourself- it's not hard to understand what his test setup was, how he measured, and what the measurements mean.
No, the red trace is with a vinyl record and thus includes the vinyl surface noise. Above 300Hz it´s S/N is about 100dB.
The blue trace is the rumble only.
If you're defining S/N as "distance to the noise floor," then CD does quite a bit better. Using the more conventional definition of S/N, CD does indeed clock in at about 96dB, but the thermal noise of a cartridge limits S/N to 70dB or so, even with perfect vinyl and a perfect turntable.
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