Wavebourn
Yes, ears can be trained but we have evolutionary traits that bias what we hear. Have a look at this post.
jan.didden
I've heard your observations about the 15kHz brick wall filter repeated. This could be due to the signal's feathery nature above that frequency or the inability of the hearing of the participant to process those frequencies which then only interfere with the rest of the sound spectra. This is primarily why I don't see the point of bandwidth over 50kHz in audio output.
Yes, ears can be trained but we have evolutionary traits that bias what we hear. Have a look at this post.
jan.didden
I've heard your observations about the 15kHz brick wall filter repeated. This could be due to the signal's feathery nature above that frequency or the inability of the hearing of the participant to process those frequencies which then only interfere with the rest of the sound spectra. This is primarily why I don't see the point of bandwidth over 50kHz in audio output.
Last edited:
If that is a concern, then all files can be made at least slightly different, so there is no point looking. That is, if the only reason to look is to see if a difference exists.
Right.
Also: many socalled "audiophiles" simply don't know how live music sounds; their perception is based on what they hear through their loudspeakers, not being aware of the real thing. It is very difficult then to have an opinion on "High Fidelity" in general, let alone the subtle differences between opamps 😉.
Jan: I remember running to the record shop ages ago after hearing a great recording/performance on FM radio. Listening to that same LP at home not seldom was a bit disappointing; it did not seem to have that FM radio filter effect maybe....
Buy the way, IMO the most ugly things about opamps is their ability to raise these endless and for the most part fruitless discussions 😀
Name an analogue source whose noise floor and distortion are not already an order of magnitude greater than almost any competent opamp circuit.
To you maybe, and as you saw cheating was easy. It was most definitely not the case with all the respondents. For me four were totally random guesses and Mooly used at lest one of the op-amps near the edge of its load drive capabilities. I think he overcomplicated the circuit BTW.
I hope you guys don't think, "Oh these all sound different", end of story. If Ed makes 5 boxes I would think you could ID all 5 individually, today, maybe next week, and with a variety of source material.
I notice the waffling about sources has already started. I have to use vinyl, oh you don't like my cartridge, arm either, yada yada yada.
Sorry, I meant an analogue source of music reproduction providing a voltage signal. A violin plus suitable microphone in a suitable venue just about counts if you can ensure that the violinist can exactly repeat a passage on demand. And there are no aircraft, tube trains etc.
I don't want to go into too much detail about this to avoid giving hints about possible methods, but let me just say this: Suppose you are using a recorded source to play music through a test box with an opamp in it, then you record the output for people to listen to. If you do the whole process twice with the same opamp, the files should be slightly different due to differences in random noise for each recording, among other things. So the files will be different while the opamp is the same.
Decided to look it up. Write-up and filter magnitude and phase response attached.
Jan
The 15kHz filter likely introduces ringing that was not present without it?
Might that alone be audible?
--------------
Demian. iirc Dafos was recorded on 1/2" two track 30 ips tape. Plenty of bass.
Most CDs I've tested have a pretty much brickwall HP filter - aka the low bass is non-existent. Why, I dunno.
----------------
LP vs. same LP played on FM.
FM stations use signal processing in the audio chain.
Put the same chain in your home, voila!
---------------
Source for "tests".
Makes zero difference.
If you are listening for noise floor, or the like, you're not listening to the soundfield. You're not listening to the individual voices and sounds... IF this changes when comparing any "boxes" inserted in the signal path, then it is different. If nothing changes, then it is the same. Simple.
--------------------
Blind, "scientific", ABX/DBT testing.
At this point, irrelevant.
This is preliminary.
The desire on the part of some to find "proof" will have to wait.
Apparently there is some anxiety surrounding this test.
On one hand those who have not or can not hear these things are concerned that they will be shown thusly.
On the other hand, they seem to hope that those who believe that they have and can hear these things will be shown to be delusional fools who believe in the tooth fairy.
So, take a deep breath and wait until something actually happens.
---------------
Of course, you are welcome to volunteer to assist and participate in a constructive manner!
I believe that Ed will be confining his present test boxes to single opamp packages.
Might that alone be audible?
--------------
Demian. iirc Dafos was recorded on 1/2" two track 30 ips tape. Plenty of bass.
Most CDs I've tested have a pretty much brickwall HP filter - aka the low bass is non-existent. Why, I dunno.
----------------
LP vs. same LP played on FM.
FM stations use signal processing in the audio chain.
Put the same chain in your home, voila!
---------------
Source for "tests".
Makes zero difference.
If you are listening for noise floor, or the like, you're not listening to the soundfield. You're not listening to the individual voices and sounds... IF this changes when comparing any "boxes" inserted in the signal path, then it is different. If nothing changes, then it is the same. Simple.
--------------------
Blind, "scientific", ABX/DBT testing.
At this point, irrelevant.
This is preliminary.
The desire on the part of some to find "proof" will have to wait.
Apparently there is some anxiety surrounding this test.
On one hand those who have not or can not hear these things are concerned that they will be shown thusly.
On the other hand, they seem to hope that those who believe that they have and can hear these things will be shown to be delusional fools who believe in the tooth fairy.
So, take a deep breath and wait until something actually happens.
---------------
Of course, you are welcome to volunteer to assist and participate in a constructive manner!
I believe that Ed will be confining his present test boxes to single opamp packages.
Last edited:
There is no right or wrong here. In any case it takes little time to compile a dozen or more testimonials right here on this site of your and my fellow DIY'ers that tried different op-amps in their projects and in some cases could not tell the difference. Of course your immediate dismissal on grounds of source material or inferior equipment, etc. does not help. Then there's Earl Geddes on modern electronics, very easy to find his posts.
Yet another post where you attribute motive and/or agenda to me. I have no interest in making anyone look foolish and I am already right. 😀
Last edited:
Here you go, if anyone wants to have their own: Orban FM Radio Products ~ Optimod-FM 8700 ~ Overview
Last edited:
I expect to have one box with ten inputs and ten outputs by mid January. It will be powered by a stand alone supply with internal regulators on each active circuit card. The box will be aluminum with a few tack welds to keep it honest.
Viewing ACTUAL audio and not computer generated test tones this mythical ringing is not evident. Greisinger has also shown the inaudibility of this and also has shown possibly why Jan preferred the filtered versions. I don't know why I bother posting some things it seems no matter how much someone's work in the audio industry is respected or what their experience and credentials are they aren't worth even having their work read.
30ips tape over FM (optimods off) by far the best sound stage I've ever heard. This was when I still had all Hafler kit electronics so you can safely ignore my experience. This was done by Victor Campos the guy that did the design for Adcom under contract so now you can really ignore it. BTW I think Victor is well respected by JC.
Scott, fwiw, I sent an email to the AD address, should you care to reply.
Why do you mention "testimonials"?
Don't see what the relationship is between testimonials and an actual test using hardware that is not a variable??
I've not dismissed anything Scott.
You've just made a presumption which is false.
Nothing I've said is that - your interpretation of my words is what you've said.
Yes, and I guess you've not read Dr. Geddes too carefully about his views on "distortion" and amplifier specs?? Seems that audibility does NOT track with distortion numbers. Eh?
Beyond that, I've not heard his speakers, which are interesting, and I disagree on some of his philosophy WRT a range of his positions.
What I said, is perhaps you ought to find another hobby if the extent of your expert input and participation is posts such as the one I previously made this hobby comment?
So, why not be constructive and assist - perhaps you will find that you end up "getting the last laugh"?
Last time I looked the different filter types all introduce varying amounts of ripple into the passband. The 15kHz filter Jan showed looks like a high slope filter.
I don't know why Jan's group preferred the filtered version.
Cite the Greisinger paper, and I'll be more than pleased to read it, and perhaps adjust my opinion, if that makes sense.
I do know that back many decades ago, it would have been quite trivial for me to hear the loss of the half octave (or more) above 15kHz, if it were switched in and out, assuming there was some noise in the signal itself, or noise floor in the electronics. No longer can do that. 🙁
As far as having "respected individuals" work read - pretty snippy remark.😱
Why not just cite a paper or publication instead? Do you think that you have read EVERY PAPER? Do you think that you have read every paper that I have?? Maybe I did read it, and filed under BS? Or just forgot about it.
Perhaps you could try bringing your point of view without the edgy/nasty part?
I can only offer that I didn't spend most of my professional career focusing on audio. I do have papers on RF systems for particle accelerators, among many other things. So, I will agree with bear that it would be great if you could cite a paper or post a link.
Sorry I'm not interested in any email conversations. I said Adcom socketed a preamp because they claimed (VC actually) that aluminum wires sounded far inferior to gold. This was an actual test using the same hardware and nobody could hear even the slightest difference. When I mentioned it you made some dismissive comment about Adcom pre-amps, how was I supposed to interpret that, was my test still valid, did two op-amps sound the same?
I was thinking more this below on Earl. His distortion metric stuff is interesting but he did turn the various distortions UP until most listeners could reliably hear them and then measure their relative annoyance factor. He points out the useful distinction between actually measuring distortion rather than THD+noise concluding a distortion measure that smoothly goes down into the noise with decreasing level is the key. This is not hard to do as you see chip amps can.
Last edited:
- Status
- Not open for further replies.