I sure didn't say that, and I wouldn't buy it either. Most bad digital sound came for old technology data converters and poorly written (they didn't know about how to do it better then) digital plugins. However, many such plugins and data converters are still in use today. On the other hand, today it is possible to make extremely high quality digital recordings, and I never said otherwise.
And, I like opamps just fine. Find them very useful. But to say that no human could possibly hear a difference between them without serious misuse appears in conflict with the exercise we just did.
Understood, this is a difficult area for research, due to people sometimes imagining differences, and confounded by prior less than optimal empirical studies, some of which were conducted under room listening conditions rather than with a good, high quality near field listening designs.
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There's some plausibility- if compensation is set up for opamp A and you switch to opamp B and the result is instability, that will likely be audible. Some opamps need little tricks done to insure stability (Ed Simon gave me one for one of the high speed Nat Semi chips, for example). Likewise, components chosen for a particular opamp's bias or noise currents may not be suitable for another opamp's requirements, which could audibly increase noise.
This won't always be the case, but it often will be.
I am not an "audiophile" 😀
I just want to know. I ask Mooly. Please let Mooly decide, if he want to play again 🙂
It's probably not possible to see the differences with actual music signals using an 8-bit digital scope. I was able to visually see differences in the test files using Reaper as a higher resolution digital scope. So, it looks like with a good ADC it should be possible to provide some kind of screen shots to show measurable differences.
Where there may be some "night and day" difference effect is probably more a function of reproduction systems, listening conditions, listener age and hearing acuity, and recent distortion recognition training/practice. For a young, working recording engineer, the difference probably better be night and day. A small wiggle in a picture of a waveform is a measurable thing, but not necessarily equally hearable by everybody in every listening situation. Any judgement about some "night and day" magnitude of effect is inherently a subjective evaluation, someone's personal opinion.
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"And, I like opamps just fine. Find them very useful. But to say that no human could possibly hear a difference between them without serious misuse appears in conflict with the exercise we just did."
OK - I think we agree on most things. I do think you have to listen carefully and it seems even in an ABX/DBT a la Mooly its more chance than certainty.
OK - I think we agree on most things. I do think you have to listen carefully and it seems even in an ABX/DBT a la Mooly its more chance than certainty.
Well I for one say 3 cheers to Mooly for trying and I think it is an interesting piece of data.
But I haven't quite got 'house' on my excuse bingo sheet yet so keep em coming 😀
But I haven't quite got 'house' on my excuse bingo sheet yet so keep em coming 😀
Meaning... get real and do some real research, back things up with facts and measurements, like I said I have seen problems when op-amps were changed, they were not night and day changes though...
You've just posted some info that again as I said has been covered in this thread, so you posted hoping to get any reply that does not agree with your own just so you can spout off... we have discussed it read and provide proff of this night and day difference, "I know what I hear" does not cut it.
Just the sort of response I expected...
Removed the rest of my rant
What you doing here then if your not an audiophile, we all are to some lesser or greater extent🙂
It was the guess comment, we don't want to guess we want clear results.
The information coming off the disc is analog....reflected light with two main levels of intensity, minimum and maximum....(and shades of grey in between).
This reflected light illuminates photodiodes and from these, dc coupled signals are derived, including the data stream.
So far so good, so far all analog.
This data stream analog signal is presented to an adaptive data slicing stage, where conversion to digital data stream is accomplished, and then processed by the DSP stage.
This digital data stream is full of jitter (as is also evident in eye-pattern waveform), and this jitter is partly dependent on the optical pit/land qualities of the CD disc.
The DSP stage contains a FIFO register the purpose of which is to remove the incoming jitter.
Somehow higher levels of data stream jitter manifest in the audio despite the DSP processing.
Some laser pickups focus and track perfectly, but the eye pattern is highly noisy and changing the pickup results in better eye pattern, and subtly better audio output.
Some CD 'pressings' have noisy eye pattern 'built in', and this can be audible.
Dan.
I have said that when op-amps have been changed in circuits from the original parts there have been differences, I know that these differences can be measured, my point was the "night and day" comment which is even less ambiguous than "eras only" in meaning... by definition it is being said there is a huge difference and there usually is if you read round this forum, 6 moons revues and a host of other Audio based drivel, the phrase is touted again and again, but always in combination of being able to use the eyes and know what is being listened too.
Mooly, I think Dan is challenging you to a CD test . . . . I for one would be interested in this.
Thanks by the way for setting up the test - very interesting.
Thanks by the way for setting up the test - very interesting.
Me too. I use them because it simple. And I learn to design discrete pre-amp because I love to design something 😀
I can not found op-amps sound different in any recording. With some recording that I familiar, sometime I found they sound different, especially for 4558 and when I play it after about 20 minute. May be it only, my hallucination 😛
I found 4558 sound a little compressed when it played music with fast beat, a sound that have a low SPL change to high SPL, fast.
No, I'm relating things that I have found on the bench over decades of servicing all kinds of gear.
Fine tuning of CDP servos has a sonic impact also, through power supply/earth interactions I expect.
Dan.
Not quite...
The data on the disk is digital not analogue, the transport method is analogue.
Someone once went through all this on this forum who was involved heavily in all this and posted some great information i would go read it...
Again I think you are attributing analogue phenomena to a digital media (it is digital its data, like broadband, that's digital data not analogue, the transport mechanism is different analogue frequencies for cable or light for fibre, but the data is digital data so can be easily recovered...
That might be interesting....in the past I have noted 'fundamental' difference in the sound of gold metalised releases, and also between CDR's.
There were black (dark red) CDR's available, and I recall they had 'something' good sounding about them.
I will put a couple of files in the next couple of days.
Is there a consensus on the best and worst sounding of the Bloody Nora opamp test files ?.
Dan.
Yes if high speed op-amps are used to replace basic ones, as said i have seen problems , not in audio analogue but instrumentation where op-amps are used, including high speed analogue. I have never seen anything really serious that I could call nigh and day, but then op-amps have been picked on numerous criteria before being chosen as a replacement. The boards were probably less prone to PCB parasitic's etc. causing problems being well laid out and multi-layer designs with good decoupling next to the relevant power pins.
Tests like this are very time consuming, at least 3 to 4 hours for something of this natures. The bulk of it needs to be done in one sitting, then there is trimming and aligning files, labelling, uploading. Seven opamps to change ten times over, burning the files to CD for the re-run......
A night and day difference to me is the kind of difference to me is the kind of difference between listening to a £15 portable CD player and a £1 to 2k model. Night and day difference, but is it ?... but in real terms the difference is still tiny and yet to an audiophile that difference takes on massive proportions.
Same with amps. Some amps have it, some don't.
Thanks guys, but as I say, the time factor is the big issue.
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