The guy asked what equipment, over and above the equipment he listed in his OP, would be handy for measuring THD.
He got responses ranging from the useful to the metaphysical.
The answer to “where can I get a good steak?” isn’t “what you want is fried chicken”.
He got responses ranging from the useful to the metaphysical.
The answer to “where can I get a good steak?” isn’t “what you want is fried chicken”.
What if the question is, "What is the quickest way to permanently disconnect all safety grounds so I can reduce hum?"
What if the question were, "what kind of solder should I buy to avoid burning my hands on the soldering iron?"
IOW, some questions are stupid questions. Only a newbie is likely to ask how to measure THD. Thinking THD measurements are going to explain why specifications don't seem to add up is also most likely to be a newbie type of misunderstanding. The guy didn't know how much he didn't know. It was not inappropriate to try to clue him in. Many people are appreciative to get information they didn't know about and that is germane to what they were thinking of doing. This guy wasn't that type as it turned out. His feelings were hurt and he left.
If you asked for steak and someone recommended chicken instead would that hurt your feelings so much you would withdraw from pubic discourse?
IOW, some questions are stupid questions. Only a newbie is likely to ask how to measure THD. Thinking THD measurements are going to explain why specifications don't seem to add up is also most likely to be a newbie type of misunderstanding. The guy didn't know how much he didn't know. It was not inappropriate to try to clue him in. Many people are appreciative to get information they didn't know about and that is germane to what they were thinking of doing. This guy wasn't that type as it turned out. His feelings were hurt and he left.
If you asked for steak and someone recommended chicken instead would that hurt your feelings so much you would withdraw from pubic discourse?
Last edited:
OP asked a perfectly valid question. Since you had nothing useful to answer you should have just refrained from posting.
Regarding THD here is what a study presented at AES convention 2014 had to say about it. Sean Olive was one of the co-writers.
"In summary, there appears to be some moderate positive correlations between the amount of THD measured in the headphones and their sound quality rating."
Regarding THD here is what a study presented at AES convention 2014 had to say about it. Sean Olive was one of the co-writers.
"In summary, there appears to be some moderate positive correlations between the amount of THD measured in the headphones and their sound quality rating."
The OP said:
Opamps aren't headphones (what are the distortion numbers on those headphones?). And the guy had no idea how to choose opamps wisely (apparently he thought it can be done by THD+N only)....I can at least choose between opamps wisely...
So, he overreacted, exaggerated, and left in a huff....So I need to be one the best engineer on the planet first, to be able to have the privilege of good measurements....
Last edited:
Appetites for online controversy vary, so perhaps unsurprising.
The thing to do is to make your point once and then tactfully withdraw.
It's not as if the risks to the OP are electrocution or bodily burns, is it?
The thing to do is to make your point once and then tactfully withdraw.
It's not as if the risks to the OP are electrocution or bodily burns, is it?
Read the post #1 again. That is not what he said.apparently he thought it can be done by THD+N only
He is still a member. I suggest you tone it down.So, he overreacted, exaggerated, and left in a huff.
No it isn't. The only point of those last two questions was to illustrate that there is some line we can all see at which point the response to a question can reasonably be to question its premise. Where that line is at seems to vary from person to person and situation to situation. In a case where there is significant danger then its easy to agree there is a line. In other cases opinions seem to be more varied.It's not as if the risks to the OP are electrocution or bodily burns, is it?
Anyway, I’m quite interested in this too.
I bought a HP 333A on a whim on eBay and restored it.
It will resolve distortion down to 0.01%, which is well off the pace i terms of what you and I need from modern equipment but it is quite handy as an auto-mulling notch filter and low noise preamp for viewing the distortion residual on the oscilloscope.
I think I were to buy one piece of kit on a reasonable budget it would be the QA304 distortion analyser. Together with an ultra low distortion oscillator, a LNA and a notch filter you could explore as much as you wanted.
I bought a HP 333A on a whim on eBay and restored it.
It will resolve distortion down to 0.01%, which is well off the pace i terms of what you and I need from modern equipment but it is quite handy as an auto-mulling notch filter and low noise preamp for viewing the distortion residual on the oscilloscope.
I think I were to buy one piece of kit on a reasonable budget it would be the QA304 distortion analyser. Together with an ultra low distortion oscillator, a LNA and a notch filter you could explore as much as you wanted.
How many physical effects in electronics devices do you think there are to measure?
Just two, harmonic distortion, and noise?
Just two, harmonic distortion, and noise?
Philosophy is not necessarily a digression. One could even argue some of it is essential and should be required coursework for all scientists and engineers.
https://en.wikipedia.org/wiki/Philosophy_of_science#:~:text=Philosophy of science is a,the ultimate purpose of science.
https://i2insights.org/2017/05/02/philosophy-for-interdisciplinarity/
https://en.wikipedia.org/wiki/Philosophy_of_science#:~:text=Philosophy of science is a,the ultimate purpose of science.
https://i2insights.org/2017/05/02/philosophy-for-interdisciplinarity/
Last edited:
A fellow member asked for some help...
Why offer a thirsty man a bowl of good???
Makes zero sense..
Just answer his question if you can help..
Why offer a thirsty man a bowl of good???
Makes zero sense..
Just answer his question if you can help..
There's a common trait to this forum (and other hobby forums, I'm sure)
1. A fellow member posts a question
2. Another member that is a staunch supporter of some 'audiophile' philosophy steps in and squashes the question because it doesn't support their philosophy
3. The thread breaks out into huge debate by hard headed members that try to persuade the original Op to change his way of thinking... As if all audiophiles will ever 100% agree with each other (never happen)
The member asked for some help. I'm not a test equipment expert but their are plenty of good techs on this forum that can answer the question in short order..
Best regards,
Brannon
1. A fellow member posts a question
2. Another member that is a staunch supporter of some 'audiophile' philosophy steps in and squashes the question because it doesn't support their philosophy
3. The thread breaks out into huge debate by hard headed members that try to persuade the original Op to change his way of thinking... As if all audiophiles will ever 100% agree with each other (never happen)
The member asked for some help. I'm not a test equipment expert but their are plenty of good techs on this forum that can answer the question in short order..
Best regards,
Brannon
Maybe you are confused, I didn't say it was the answer.Btw Markw4, 42 is not the answer to the question...
Besides, I didn't ask you if it was the answer to the question. Maybe you should have kept quiet since you weren't asked.
- Home
- Design & Build
- Equipment & Tools
- Help me start my measuring tools