What I find difficult to comprehend, is why people would go to the effort of oversized transformers and oversized reservoir capacitance, then realise they cause a spray of mains harmonics from the sharp, tall charging current pulses, then call up all kinds of chokes to migitate the oversized transformer and capacitance again.
To me that doesn't seem a very smart way to design your stuff, but probably I am missing something?
Jan
I have found that is apparently: THE RETURN PATH of the power supply that, when made lower Z over frequency, is what improves the subjective performance of the audio device. That is why we 'overbuild' power supplies.
I had this out with Nelson and his staff, about 25 years ago. He ultimately copied my efforts, much to my relief.
I had this out with Nelson and his staff, about 25 years ago. He ultimately copied my efforts, much to my relief.
It is NOT A FASHION. It is the audio reality of what works!
PMA, you are one of the best engineers around, BUT you will lose, if you are not more flexible and more open about subjective listening experiences. Be warned! '-)
PMA, you are one of the best engineers around, BUT you will lose, if you are not more flexible and more open about subjective listening experiences. Be warned! '-)
Assuming, for the time being, that this is true, what does it have to do with this:
😕
Jan
'overbuild' note the parenthesis. It depends on the definition of 'overbuild'. Perhaps it is proper sizing, instead.
I guess you're not going to explain that to us unwashed masses?
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For small-signal stuff, which is what we are discussing here, no specific ratio. I calculate what I need, then take the next one up. Not too large caps to keep the mains harmonics under control, soft recovery rectifiers to keep rectifier switch-off spikes under control, then follow up with a good regulator. Make sure the reg has 5V headroom at lowest mains voltage expected.
Make sure all return paths are defined and cannot impact each other, and keep them apart from the signal return. That sort of common-sense engineering stuff.
Then after I finish it I listen to it, and it always sounds exceptionally clean, wide sound stage, very realistic, you know.
Useless for marketing, I know. 😉
Jan
> I did measure an Avel years ago and was surprised by the bandwidth it had.
Right-O ...... Actually usable as output xfmrs.
Right-O ...... Actually usable as output xfmrs.
At low frequencies, larger caps have lower impedance than smaller caps. Another note: We usually do NOT use center tapped supplies unless absolutely necessary. This further isolates the system ground from the power line. This may be necessary also for preamps.
I got lots of friend who all drive Audi's and have the best ears this side of the pond. They take me to lunch sometimes, too!
One of them used to consult for that guy with the cold fusion, forgot his name, but very famous! So there!
Jan
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Thanks for the response, have you ever tried doubling/tripling what you think is required ..?
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