It is again an easy to understand video, exlaining an important topic. Thank you John for devoting your time to educate us by your Channel. Quite a few people spend time to give (positive) feedbacks, but your vids help a lot for enthusiastic amateurs to understand audio and electronics. Well done, keep it going :)
Thanks John, this helped fill some more gaps in me brain pan Could you do a vid on how a guitar output differs from line out, speaker out and phono out? And possibly how to convert those signals to work with one another with and without preamps? I could send you some guitar parts if you need them to figure it out.
Good video, it would have been real nice to see the AC input/output voltage with relation to the ratio of gain with different DC supply voltages (THIRD)
Another nice video - keeping it simple with a good example. I was first concerned that the measurement might be out of the bandwidth of your meter - but you reported the bandwidth of the meter and took the measurement well within that bandwidth.
I must admit I got a bit lost. If in the first set of measurements you varied something to get the output just below clipping how did you later adjust something else to get a different figure? I must have missed something.
The first measurement was the gain. The second was the input signal level required to drive the amplifier to the point just before clipping (max clean output). The second measurement is a function of gain and supply voltage.
For the first time I strongly disagree with your approach. Your math is wrong, the circuit you describe as your DUT is actually a voltage divider, your understanding of the whole concept of audio measurement is crazy. An analog scope at or below 100 MHz is less than $100. Even a brilliant Tektronix version. I have 4 sitting in a pile. I give them to kids. There is no excuse for this folklore audiophoolery. People can find $100 if they are designing audio amps. This kind of utter nonsense will only hold people down. All that rant aside, thumbs up to support your channel.
Its fine as a rough measurement for these purposes. With the attenuation resistor at 100ohm , there is only a small portion of output going through the speaker.
I think the author of the video made an assumption: people watching the video have some basic knowledge so he don't have to explain really basic concepts or some simplifications he made. I found the approach clever, it allows you to quickly accomplish the task with good enough results.
Have you ever done a video on( LJM MX50 SE ) from www.ljmaudio.com I bought a set of boards rated at 100 W each at 45 V DC input. They came complete with all the components +2 circuit boards. I just received my two boards in the mail will start assembling them would like to see you give them a test and how you would rate them for 11 bucks for 100 W per channel
Many times I have wished 'experts' would come. down to my level. You are one of the few who can do that. Thank you.
It is again an easy to understand video, exlaining an important topic. Thank you John for devoting your time to educate us by your Channel. Quite a few people spend time to give (positive) feedbacks, but your vids help a lot for enthusiastic amateurs to understand audio and electronics. Well done, keep it going :)
Another nice educational video. Thanks, John!
Thanks John, this helped fill some more gaps in me brain pan
Could you do a vid on how a guitar output differs from line out, speaker out and phono out? And possibly how to convert those signals to work with one another with and without preamps?
I could send you some guitar parts if you need them to figure it out.
Bel video, complimenti!!
I enjoy watching your video s
Thanks! Nice to have someone from Kenya watching.
Good video, it would have been real nice to see the AC input/output voltage with relation to the ratio of gain with different DC supply voltages (THIRD)
The gain is independent of the supply voltage.
what about trying.. p = i x v etc too
Nice
Another nice video - keeping it simple with a good example. I was first concerned that the measurement might be out of the bandwidth of your meter - but you reported the bandwidth of the meter and took the measurement well within that bandwidth.
Good stuff to know.
I must admit I got a bit lost. If in the first set of measurements you varied something to get the output just below clipping how did you later adjust something else to get a different figure? I must have missed something.
The first measurement was the gain. The second was the input signal level required to drive the amplifier to the point just before clipping (max clean output). The second measurement is a function of gain and supply voltage.
thank you!.
Second
For the first time I strongly disagree with your approach. Your math is wrong, the circuit you describe as your DUT is actually a voltage divider, your understanding of the whole concept of audio measurement is crazy.
An analog scope at or below 100 MHz is less than $100. Even a brilliant Tektronix version. I have 4 sitting in a pile. I give them to kids.
There is no excuse for this folklore audiophoolery. People can find $100 if they are designing audio amps. This kind of utter nonsense will only hold people down.
All that rant aside, thumbs up to support your channel.
The price of a 30 year old analog Tek heavily depends on the region you buy it. In Europe a good used Tek goes for about $300.
Its fine as a rough measurement for these purposes. With the attenuation resistor at 100ohm , there is only a small portion of output going through the speaker.
Apparently it is "folklore audiophoolery". Thats why!!
I think the author of the video made an assumption: people watching the video have some basic knowledge so he don't have to explain really basic concepts or some simplifications he made. I found the approach clever, it allows you to quickly accomplish the task with good enough results.
Show me what's wrong with the formulas/methods used. I'm always ready to debate when someone tries to call me out.
Have you ever done a video on( LJM MX50 SE ) from www.ljmaudio.com
I bought a set of boards rated at 100 W each at 45 V DC input. They came complete with all the components +2 circuit boards. I just received my two boards in the mail will start assembling them would like to see you give them a test and how you would rate them for 11 bucks for 100 W per channel