Boris is brilliant. A clever guy pretending to be a buffoon........converse of the US situation where Trump, is a buffoon pretending to be a clever guy.......
Oh everyone knows what Boris is about, I just find it enjoyable to have a politician with a bit of character.
For many applications the Octave (open source and free Matlab alternative) is good enough:
- https://www.gnu.org/software/octave/
At least if your code does not depend on "premium" Matlab libraries.
... Typical audio analyzer is an analog to digital converter (ADC) with a bunch of software.
In the case of Audio Precision analyzers, they also have excellent auto-scaling "gain" stages that can amplify or reduce the levels of signals to allow very wide dynamic range. When fed strong signals though, the ADC can produce its own noise and harmonic distortion which can be confused with the device under test.
The late Dr. Tom Kite explains and demos this well in this short video:
Technically, this is the simplified architecture of APx555:
View attachment 13093
In addition to above analysis hardware, the generator is also improved to have lower distortion. Ironically, this is an analog solution that beats the digital one (a DAC)!!! Sometimes old technology beats new. Combined these too and looping the APx555 to itself produces this on my bench: ...
No, it can't be used as a music device. And the answer you seek is in the post you quoted.Hi and sorry to jump in but i am confused. I am not an expert. But you talk about a fully analog device here ? but from the schematic i see that the incoming analog signals are still converted to digital. So the device is actually like a state of the art AD/DA converter ? I would be curious to know which ADC and DAC are used in this exceptional equipment. And sorry but i have to ask a silly question ... does this device sound ? can it be used as a high end musical ADC o DAC ? the noise is practically absent and the distortion as well.
Thanks a lot for all your excellent work.
Kindest regards, gino
They also often had TIM/DIM issues.
@pma
Yamaha conservatively specified THD from a few milliwatts to rated power across the entire bandwidth from 20Hz -20Khz.
They also specified the IMD at half rated power, 60Hz:7kHz 4:1 at less than 0.003%.
"They". Let's be specific shall we? What actual (brand and model) amplifiers had TIM/DIM issues? What were those issues exactly? Pick a few you can think of- I may have them in my collection to test.
There are not many trusted measurements on vintage amplifiers left. It is rather in a memory, that anything that had uA741 and similar parts inside used at higher than 1V level had SID/TIM issues.
60Hz+7kHz is nothing, it is an easy task for the amp.
I beg to differ. The published measurements on vintage amplifiers were extensive, exhaustive and highly verifiable, because they often appeared in various monthly publications around the world. Correlation and comparison was easy.
60Hz and 7KHz is not an easy task at all. You will see all sorts of PSU related IM products as it's right on mains frequency.