Charles Hansen said:
of course you do Charles..... its the primacy, and absolute truth of THEIR 'thought experiments'. Its not required that they actually verify their conclusions empiracally, as they KNOW, by virture of their fine education and experience.
Now this will inevitably segue into a discussion of empirical verification; when can we trust our own ears and the endless tortured discussions of DBTs, etc....
We all know that our own 'thought experiments' are perfectly valid, its the other dumb schmucks conclusions that are so misguided.
I will posit that the reason some folks can hear a difference with an RC network in parallel with the filter capacitor is that stray RF or EMI has made its way into their design -- and the RC network provides a convenient low impedance to deal with it -- so we might ask -- is this a problem of improper dressing of the power supply leads, a connection which isn't properly soldered, a transformer problem (yes, toroids do radiate) --
i do know that their is an obvious tank circuit in the power supply --
i do know that their is an obvious tank circuit in the power supply --
janneman said:
Fine for me, it was not a personal attack, it's what happens on this forum, every day.
'Have you seen this?' <link to commercial product>
At least think this way: who doesn't sell anything doesn't have anything to gain or to loose, so he/she can be at least given some more credit for an oppinion or a report.
What costs you to try snubbers, Jan?
Have you?
What's your oppinion?
I don't know why are you posting on this thread, then...
carlosfm said:
I haven't tried them, and I haven't any opinion on them. There are many things I try, and possibly I will go around to try snubbers as well, one time.
Did you get that Carlos? I DO NOT have an opinion on the audibility of you famous snubbers in all its various cases and uses.
I DO have an opinion on people who state things so very strongly and defend their OPINION as if their manhood depends on it, going so far as to call other people names. My experience is that you learn more important things from people who go out of their way to proof themselves wrong, trying to avoid every possible external influence, but finally come to the conclusion that they really are on to something.
carlosfm said:
I would think it is the same reason as you have Carlos .
Jan Didden
Have you noticed folks that I have said anything yet 
I have also noticed that noone (yes?) has actually measured the resonance in the PS in question, then calculated and/or just grabbed some parts and then measured again to see the results, then listened. It seems that people can hear if the snubber is connected without knowing if the resonance is removed or even reduced.
I have also noticed that noone (yes?) has actually measured the resonance in the PS in question, then calculated and/or just grabbed some parts and then measured again to see the results, then listened. It seems that people can hear if the snubber is connected without knowing if the resonance is removed or even reduced.
PA -- remember this?
you can "guesstimate" the resonance, but the diode's capacitance may not be quite what the manufacturer's data sheet says. (it's a function of voltage).
jack
An externally hosted image should be here but it was not working when we last tested it.
you can "guesstimate" the resonance, but the diode's capacitance may not be quite what the manufacturer's data sheet says. (it's a function of voltage).
jack
I've tried to measure resonances in power supplies, but I couldn't find any. Interestingly, what the waveforms showed is that electrolytic capacitors are not as inductive as we expect at high frequencies (a very common myth), they are mainly resistive.
Also, to my surprise, paralelling electrolytics (>22uF) with 100nF ceramics or 1uF MKT resulted only in mild to serious resonance issues. I couldn't measure any remarkable amplitude reduction in the voltage spikes caused when current pulses were drawn from electrolytic capacitors, altough I have to admit that these pulses hadn't much frequency content above 5Mhz or so. In fact, adding these small capacitors sometimes increased spike amplitude due to ringing.
Also, to my surprise, paralelling electrolytics (>22uF) with 100nF ceramics or 1uF MKT resulted only in mild to serious resonance issues. I couldn't measure any remarkable amplitude reduction in the voltage spikes caused when current pulses were drawn from electrolytic capacitors, altough I have to admit that these pulses hadn't much frequency content above 5Mhz or so. In fact, adding these small capacitors sometimes increased spike amplitude due to ringing.
Eva said:
It's not a surprise to me. I avoid adding small bypasses (in that matter, any bapasses) as it never sounds right to me.
Actually, the biggest improvement I did to my ML37 transprt was removing all those double bypasses (ceramics, tantalums or polyp.) and leaving only single electrolytics in each location (of course, much smaller capacitance).
Eva said:
the toroids I used had pretty small leakage inductance (uH) -- but the EI transformer I used in my very low noise amplifier (it was in a Hewlett Packard amplifier which I modded, or rather gutted) had leakeage inductance in the milliHenries and it did ring.
the pix I showed were from a surplus transformer I got at my favorite electronics dumpster.
but I would like to get back to the point at the beginning of Charles' observation -- that is, that he experienced a difference in sound staging -- and I am wondering what's cooking in the layout, or if there is some design issue which needs attending.
Peter Daniel said:
Nothing new under de sun ...look at this thread in 2002 ...
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1087&perpage=10&pagenumber=2
Tube_Dude said:Nothing new under de sun ...look at this thread in 2002 ...
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1087&perpage=10&pagenumber=2
I also don't like parallel electrolytics.
peranders said:
I have said several times that completely REMOVING the resonance is not the main point. It is not possible to completely remove (it is possible to attenuate), and removing the peak is not what I have in mind when I do my calcs.
You have to know what you are looking for, otherwise you are lost.
Eva said:
Inductance creates rising impedance towards high frequencies.
Basic loudspeaker design stuff.
planet10 said:
On the first post of my first thread about snubbers I provide a link to a TNT-Audio article, and explained why I thought it was the answer to the bad sonic results with high capacitance and these chips. Nevermind, when I posted that I already knew it was the answer. I had already tested, including A-B tests (which are not difficult to make).
I have done much homework since then, but I never claimed to have invented anything.
That is in some people's minds, but I have no responsibility about it.
Interestingly, when the discussion gets hot, sometimes it happens that someone throws to my face that I haven't invented anything, this is old story.
Well, those can come here and explain everything.
Btw I also miss Eric (mrfeedback), he is missing on this forum, as well as Fred Dieckmann, Pedja and some other guys.
Things are not the same without these people.
Eva,
Evey time you post, it gets a little simpler to build a basic unregulated, linear PS for my next amp. Adding the little caps parrallel to the reservoir caps and then soldering a ring of caps around the bridge rectifier was always kind of fiddly and ugly anyway.
As long as we are talking snubbers, have you any experiences with quieting triacs. I wasted over a month last spring trying to make a triac soft start circuit. I stuck snubbers where all the app notes said they should go and even tried the scheme where you controll the main triac with a smaller sensitive gate type. I managed to reduce the noises (both audible and on the scope), but never enough to be satisfied. Finally dumped the whole thing and went back to a the relay and power resistor method.
Evey time you post, it gets a little simpler to build a basic unregulated, linear PS for my next amp. Adding the little caps parrallel to the reservoir caps and then soldering a ring of caps around the bridge rectifier was always kind of fiddly and ugly anyway.
As long as we are talking snubbers, have you any experiences with quieting triacs. I wasted over a month last spring trying to make a triac soft start circuit. I stuck snubbers where all the app notes said they should go and even tried the scheme where you controll the main triac with a smaller sensitive gate type. I managed to reduce the noises (both audible and on the scope), but never enough to be satisfied. Finally dumped the whole thing and went back to a the relay and power resistor method.
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