Who are these people that you're shadowboxing? And the rudeness sword has cut both ways and seems you've joined the mob.
Likewise, other than creating a caricature of their opposing ideology, who has actually claimed there possibly cannot be something there? Go ahead and link the post. Pretty sure the discussion by "You know who you are" (this shaming is much more insidiously insulting than other means, at least others aren't pretending to hide behind some pseudo-neutrality and psychoanalyses) has been on magnitude of effect, or origins of major, audible changes.
So as to the results of Mooly's test looking awfully null, I told you so. And yes, I can quote myself if I need to.
Mooly--thank you for this test. I wasn't in the right head space to participate, but have in the past and your efforts here are duly appreciated.
The circuit Z makes a fairly large difference in how the opamp behaves. The THD meter - HP339A - has an oscillator that is based on an opamp. When trying different opamps, the THD was all over the place... and not always representative of the spec sheet. I finally found one that gave the lowest THD for the circuit Z's being used. Also, as SW pointed out, the CM distortion on some opamps (eg 797) can be relatively high if the circuit Z's are not balanced.
From that exercise, it is very likely that distortion of several types will change compared to results from a fixed Z values used for measuring all opamps doesnt show this variability. But in Your circuit using different Z, you might get different results like I did with the opamps I tried in the 339A.
THx-RNMarsh
From that exercise, it is very likely that distortion of several types will change compared to results from a fixed Z values used for measuring all opamps doesnt show this variability. But in Your circuit using different Z, you might get different results like I did with the opamps I tried in the 339A.
THx-RNMarsh
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Daniel: You can go join a debating team and argue for whatever positions you like, or that are assigned to you. You are wrong about many things, too many to enumerate, and, frankly, not worth the time to bother with. Your ad hominem complaints are truly without merit. I don't wish to speak further with you at this time. Good day.
I would have participated but since my audio system is in pieces didn't think it appropriate to use my laptops audio for any kind of critical listening. I also wouldn't expect the audio output to a set of headphones to be appropriate to this type of testing. The fact that Jay pulled out the one particular opamp is rather impressive, not sure of the statistical probability of that as a guess? But it does seem that people are picking nits to tell any real differences, there is no night and day oh my god problem with any of the the opamps it seems. The differences are there, they are real and they are minimal, personal preferences at best it seems.
While looking at the graph that I think was put up by Mooly I could clearly see a difference in the small details, there were some clearly visible height differences in small spikes, now whether they are audible is the question and why those are so is another question.
Do all opamps sound identical, no, is it a significant difference if the circuit isn't misbehaving not really. Can a great circuit designer take advantage of an individual opamp, probably so if they know what they are looking for and how to optimize for that particular opamp. Should audiophiles roll opamps and expect a major improvement, I don't think so. Can you mess up a perfectly good circuit by rolling opamps, it seems very probable and definitely possible with high speed opamps where low speed opamps were originally designed for.
While looking at the graph that I think was put up by Mooly I could clearly see a difference in the small details, there were some clearly visible height differences in small spikes, now whether they are audible is the question and why those are so is another question.
Do all opamps sound identical, no, is it a significant difference if the circuit isn't misbehaving not really. Can a great circuit designer take advantage of an individual opamp, probably so if they know what they are looking for and how to optimize for that particular opamp. Should audiophiles roll opamps and expect a major improvement, I don't think so. Can you mess up a perfectly good circuit by rolling opamps, it seems very probable and definitely possible with high speed opamps where low speed opamps were originally designed for.
Mark, have a lovely day. I'm absolutely wrong about a number of things, no doubt. Look forward to your diatribe on why I won't ever amount to anything. Oh wait, you've already done that.
Look at the sample. The critical spec. All the same. Slew rate - Slew rate - Slew rate..... Throw an AD811 with a fast power supply in the mix. Try it! But you won't. You guys are like sheep.
Oh, and you may have read some where, like Gearslutz or some such, about modding a big mixing console and putting fast opamps in maybe the mic pre circuit, or the EQ circuit, and getting no difference. You know why? Two reasons! FIRST, the big reason, the power supply regs are located way far away from the opamps - the long trunk line series resistance (both feed and ground return) eats the power supply speed and such chokes the speed of the op-amp. SECOND all the other opamps, like in the summing channels, usually have not been changed so the micro-dynamics never make it to the outputs because the 20v/us devices (THERE IS THAT SO-SO SLEW RATE NUMBER AGAIN!) eat it up.
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AAAAND bingo!
Seriously I must see if Mooly has the gerbers for that tone board. I want to build one.
Seriously I must see if Mooly has the gerbers for that tone board. I want to build one.
I have Diptrace files for it but there are no component references on the board (its easy to suss out though from the circuit).
DipTrace - Schematic and PCB Design Software
DipTrace - Schematic and PCB Design Software
Attachments
That's an (excellent) repurposed DSL line driver. Where slew rate demands orders of magnitude greater than rail-to-rail 20 kHz sinusoids. The AD811 is another (excellent) video opamp, especially I/V--there's certainly merit of having wider bandwidth here to cleanly pass DAC spurs, although filtering HF hash before the I/V opamp is probably a better idea.
Mooly,
That gerber is from the Elektor Doug Self preamp I suppose? Is there anything missing besides the component positions or are there a lot of other pieces missing? I remember there were many sub boards in the Elektor kit that I looked at in the past.
That gerber is from the Elektor Doug Self preamp I suppose? Is there anything missing besides the component positions or are there a lot of other pieces missing? I remember there were many sub boards in the Elektor kit that I looked at in the past.
I suggest all EEs who share Bob Pease attitude about electronics, be sent to Mars (one way ticket), carry with them all the copies of the books he wrote. His way of seeing circuits is detrimental to society
George
Lower probability. MUCH lower. Getting one right (without specifying in advance which one) is much more expected. I'll leave the basic probability calculations as an exercise for the reader.
Thank you Bimo, to bad we don't have Ostripper here to bring some alternative thinking and real world design application to this discussion.
😕
I have utterly no idea what you're railing against.
Perhaps you're wanting to add something to this already drawn out thread? http://www.diyaudio.com/forums/soli...est-realistic-audio-transient-terms-v-us.html
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