Lars Clausen said:
I haven't seen anything here that would change my mind,
and given that a subjective evaluation is the final word on the
subject (at least for me), it's going to be a difficult thing for you
to achieve.
As far as the graphs go, they look like noise spikes to me, but I
stand ready to be wrong, and not for the first time.
Hello.
There is no doubt in my mind that a lot of people on this forum know a lot more than me, but I have modified my amp ( with: Sprague/Chemi-Con caps.) to use a V4P setup of the caps.
I have to tell that the amp. have been used daily fore nearly 3 years before this modyfication. So I think I know the sound of it by now.
What I did, was placing resistors, in the same way as shown in this tread.
Does it work? Yes Yes Yes! The amp is transformed into another league!
A lot bigger soundstage especialy to the back., no harsh sound at all. Voises more naturel. More dynamic , but also a lot nicer to the ears.
It`s really hard to stop listening, once You started!
My point is this: Why worry about ways of messuring it, try it out on an amp Yourself! It speaks for itself.
Best Regards: Dyno
There is no doubt in my mind that a lot of people on this forum know a lot more than me, but I have modified my amp ( with: Sprague/Chemi-Con caps.) to use a V4P setup of the caps.
I have to tell that the amp. have been used daily fore nearly 3 years before this modyfication. So I think I know the sound of it by now.
What I did, was placing resistors, in the same way as shown in this tread.
Does it work? Yes Yes Yes! The amp is transformed into another league!
A lot bigger soundstage especialy to the back., no harsh sound at all. Voises more naturel. More dynamic , but also a lot nicer to the ears.
It`s really hard to stop listening, once You started!
My point is this: Why worry about ways of messuring it, try it out on an amp Yourself! It speaks for itself.
Best Regards: Dyno
Why measure it? Because understanding the phenomenon and being able to quantify it in a reproducible manner is the only way to make real progress.
I fear we'll never see any measurements that make any sense coming out of Mr. Clausen and that like NP says all that was discovered was the benefit of having a couple of dB lower noise in the PS.
I fear we'll never see any measurements that make any sense coming out of Mr. Clausen and that like NP says all that was discovered was the benefit of having a couple of dB lower noise in the PS.
the messeger or the message........
From:
http://www.panasonic.com/industrial/components/pdf/aluminum_app_dne.pdf
1.4 Using Two or More Capacitors in Series
or Parallel
(1) Capacitors Connected in Parallel
The circuit resistance can closely approximate the
series resistance of the capacitor causing an
imbalance of ripple current loads w i t h in the
capacitors. Careful design of wiring methods can
minimize the possibility of excessive ripple currents
applied to a capacitor.
I agree that part of the beneficial effects are probably from reduction of peak charging current. The reverse recovery voltage is a function of the peak forward current of a rectifier. Dividing the charging currents equally between multiple caps seems to me to be a good idea for the standpoint of reliability and in terms of distortion and changing of capacitor ESR with heating. Resistances between the filter caps and a film bypass seem to be a good idea from the standpoint lowering the q of the resonant circuit from inductance of the filter caps and wiring or PCB inductance and the high Q film cap. Capacitor Q in circuit is becoming more important as capacitor ESR for electrolytics approaches a few milliohms. Filter capacitor noise voltages are reduced by averaging in a similar manner to paralleling voltage reference for lowest noise. This looks more like egineering than voodoo to me.To paraphrase the old joke, we know what it is and are merely quibbling over how much.
http://www.evox-rifa.com/europe/electrolytic_life_factors.htm
From:
http://www.panasonic.com/industrial/components/pdf/aluminum_app_dne.pdf
1.4 Using Two or More Capacitors in Series
or Parallel
(1) Capacitors Connected in Parallel
The circuit resistance can closely approximate the
series resistance of the capacitor causing an
imbalance of ripple current loads w i t h in the
capacitors. Careful design of wiring methods can
minimize the possibility of excessive ripple currents
applied to a capacitor.
I agree that part of the beneficial effects are probably from reduction of peak charging current. The reverse recovery voltage is a function of the peak forward current of a rectifier. Dividing the charging currents equally between multiple caps seems to me to be a good idea for the standpoint of reliability and in terms of distortion and changing of capacitor ESR with heating. Resistances between the filter caps and a film bypass seem to be a good idea from the standpoint lowering the q of the resonant circuit from inductance of the filter caps and wiring or PCB inductance and the high Q film cap. Capacitor Q in circuit is becoming more important as capacitor ESR for electrolytics approaches a few milliohms. Filter capacitor noise voltages are reduced by averaging in a similar manner to paralleling voltage reference for lowest noise. This looks more like egineering than voodoo to me.To paraphrase the old joke, we know what it is and are merely quibbling over how much.
http://www.evox-rifa.com/europe/electrolytic_life_factors.htm
Attachments
Jumping to conclusions?
A agree with there being merit to some of the technical issues outlined........ not to questionable explanations and measurements. Lars has possibly gone out on limb but that doesn't negate the capaciitor circuit considerations, just some of the explanations and measurements that have been put forward. Power design for audio is not nearly as straight forward as one might think.
A agree with there being merit to some of the technical issues outlined........ not to questionable explanations and measurements. Lars has possibly gone out on limb but that doesn't negate the capaciitor circuit considerations, just some of the explanations and measurements that have been put forward. Power design for audio is not nearly as straight forward as one might think.
Speaking of measurements, I just went out to production
and used an rms AC voltmeter to measure the AC voltage
across one of 4 parallel supply capacitors and the voltage
loss between parallel terminals on a running X1000.
The number is about 100 to 1, meaning that the impedance
of the capacitor is about 100 times the impedance of the
connection. This tells me that the mismatching in sharing
between capacitors is about 1%. I don't consider that to be
significant.
and used an rms AC voltmeter to measure the AC voltage
across one of 4 parallel supply capacitors and the voltage
loss between parallel terminals on a running X1000.
The number is about 100 to 1, meaning that the impedance
of the capacitor is about 100 times the impedance of the
connection. This tells me that the mismatching in sharing
between capacitors is about 1%. I don't consider that to be
significant.
I've re-read the whole thread and still don't get a word of it.
So, we have a circuit with a number of small capacitors linked in series by leads of finite resistance. If the lead resistance gets too big, the impedance at the output will look more like that of the final capacitor, not all of them in parallel. Yes, no problems understanding that, but NP has measured this and (at least for him) this is a non-issue.
Next we have a picture of a "wave of charge" passing from capacitor to capacitor on each charging cycle. Yes, the voltage graphs look a bit like that. But note that it is not a wave in the technical sense of the word. Voltages in this sort of network do not obey the wave equation; you need an LC-based network for that, and this is not one of them. This means that thinking of a wave bouncing back and forth from end to end of this network is strictly fanciful. It won't happen in simulation, and I doubt you'll measure it in real life.
Supposing I'm wrong, can somebody please tell me what I will measure at the output of my power supply, with and without 'woppling'. Assume for now that if I can't measure it, I'm not interested in listening for it.
Cheers
IH
So, we have a circuit with a number of small capacitors linked in series by leads of finite resistance. If the lead resistance gets too big, the impedance at the output will look more like that of the final capacitor, not all of them in parallel. Yes, no problems understanding that, but NP has measured this and (at least for him) this is a non-issue.
Next we have a picture of a "wave of charge" passing from capacitor to capacitor on each charging cycle. Yes, the voltage graphs look a bit like that. But note that it is not a wave in the technical sense of the word. Voltages in this sort of network do not obey the wave equation; you need an LC-based network for that, and this is not one of them. This means that thinking of a wave bouncing back and forth from end to end of this network is strictly fanciful. It won't happen in simulation, and I doubt you'll measure it in real life.
Supposing I'm wrong, can somebody please tell me what I will measure at the output of my power supply, with and without 'woppling'. Assume for now that if I can't measure it, I'm not interested in listening for it.
Cheers
IH
IanHarvey: It seems to me that you understand more than you give yourself credit for.
For now i will only add that you should not entirely think of your power supply as 'what you can measure at the output'. It would be like measuring the light coming in through a glass window.
The measured light may be the same but there is a lot of difference between looking at a junkyard or a mountain landscape outside.
In other words (according to my claim anyway) the amplifier not only sees how many Volts come out of your power supply, it 'looks inside' the power supply. Every aspect of the power supply may have an effect on the sound. Even if no difference can be seen in Volatge, Amperage, Impedance or Ripple.
After all in any un-bridged amplifier your speaker signal passes right through your power supply's capacitors. This effectively means the capacitor's impedances and resonances are in series with your speakers.
For now i will only add that you should not entirely think of your power supply as 'what you can measure at the output'. It would be like measuring the light coming in through a glass window.
The measured light may be the same but there is a lot of difference between looking at a junkyard or a mountain landscape outside.
In other words (according to my claim anyway) the amplifier not only sees how many Volts come out of your power supply, it 'looks inside' the power supply. Every aspect of the power supply may have an effect on the sound. Even if no difference can be seen in Volatge, Amperage, Impedance or Ripple.
After all in any un-bridged amplifier your speaker signal passes right through your power supply's capacitors. This effectively means the capacitor's impedances and resonances are in series with your speakers.
I Think This Is An Excellent Technique.......
To me looking at the circuit given by Lars is a standard rectifier bridge/capacitor supply feeding each of four capacitors via 0.1 ohm resistors.
The first capacitor is subject to the usual ringing excitations caused by the secondary inductance/capacitance values and diode switching behaviours.
The next stage is four RC shunt (damping/snubber) networks supplied in parallel, and each of these individual RC networks infact has the other three networks as additional RC networks.
The final four resistors and 22uF PP capacitor constitute further high frequency damping of the supply system.
All of these snubbing networks also constitute dampers for energy returning from reactive loads.
The series resistors will of course cause voltage drooping proportional to load current, but the resistor values shown would cause 1V drop at 20 Amperes and not any real issue - correct me if I am wrong.
This constitutes a pretty low, but not infinitely low impedence supply, that should have no ringing components caused by rectifier pulses, nor load variations nor load reflections.
For the sake of eight resistors in addition to the normal capacitance (except divided between five capacitors), this looks to me to be an effective way of building a totally non-resonant supply, and in my experience a 'quiet' supply pays very nice subjective sonic dividends in terms of clearness, control and non-reactiveness and harshnesses.
I have tried a standard supply with a same value capacitor and sub 1 ohm series resistor in parallel to provide damping/snubbing and this gave good result.
I expect Lars' more extensive solution is an exceptionally good one.
Nelson is correct in what he has measured, but this is not looking for supply resonances, and in any case this is probably of much less importance with his class A amplifiers.
Thinking about it, the output stage and speaker load constitute damping for a conventional supply, and this probably is a large part of class A subjective sound.
Eric.
To me looking at the circuit given by Lars is a standard rectifier bridge/capacitor supply feeding each of four capacitors via 0.1 ohm resistors.
The first capacitor is subject to the usual ringing excitations caused by the secondary inductance/capacitance values and diode switching behaviours.
The next stage is four RC shunt (damping/snubber) networks supplied in parallel, and each of these individual RC networks infact has the other three networks as additional RC networks.
The final four resistors and 22uF PP capacitor constitute further high frequency damping of the supply system.
All of these snubbing networks also constitute dampers for energy returning from reactive loads.
The series resistors will of course cause voltage drooping proportional to load current, but the resistor values shown would cause 1V drop at 20 Amperes and not any real issue - correct me if I am wrong.
This constitutes a pretty low, but not infinitely low impedence supply, that should have no ringing components caused by rectifier pulses, nor load variations nor load reflections.
For the sake of eight resistors in addition to the normal capacitance (except divided between five capacitors), this looks to me to be an effective way of building a totally non-resonant supply, and in my experience a 'quiet' supply pays very nice subjective sonic dividends in terms of clearness, control and non-reactiveness and harshnesses.
I have tried a standard supply with a same value capacitor and sub 1 ohm series resistor in parallel to provide damping/snubbing and this gave good result.
I expect Lars' more extensive solution is an exceptionally good one.
Nelson is correct in what he has measured, but this is not looking for supply resonances, and in any case this is probably of much less importance with his class A amplifiers.
Thinking about it, the output stage and speaker load constitute damping for a conventional supply, and this probably is a large part of class A subjective sound.
Eric.
Attachments
Junk In The Supply Gets To The Speakers..........
"Supposing I'm wrong, can somebody please tell me what I will measure at the output of my power supply, with and without 'woppling'. Assume for now that if I can't measure it, I'm not interested in listening for it."
A conventional supply when loaded will be Dc with a sawtooth on top, and additional noise and ringing caused by rectifier/primary ringing, and also load variations and energy returned from reactive loads.
Paralleling main supply capacitors can make this worse actually, as can adding lower value parallel capacitors.
The non-woppling supply ought to be pretty free of saw toothing, and ought to have no ringing.
Amplifier PSRR is not infinite, and providing a 'dead' supply makes for a 'quieter' and 'blacker' amplifier - ie lower THD, IMD and load sensitivity.
Eric.
"Supposing I'm wrong, can somebody please tell me what I will measure at the output of my power supply, with and without 'woppling'. Assume for now that if I can't measure it, I'm not interested in listening for it."
A conventional supply when loaded will be Dc with a sawtooth on top, and additional noise and ringing caused by rectifier/primary ringing, and also load variations and energy returned from reactive loads.
Paralleling main supply capacitors can make this worse actually, as can adding lower value parallel capacitors.
The non-woppling supply ought to be pretty free of saw toothing, and ought to have no ringing.
Amplifier PSRR is not infinite, and providing a 'dead' supply makes for a 'quieter' and 'blacker' amplifier - ie lower THD, IMD and load sensitivity.
Eric.
A Bell MUST Ring, And A Reproduce System MUST NOT........
I beg to differ that these are not quite the same thing.......
Directly paralleled capacitors do not have external damping between them, and are free to interact according to the parasitic characteristics of each.
This interaction can cause supply/circuit/load resonances that may or may not be present all the time, and may be transiently triggered by supply or circuit or load characteristics/parasitics, or all three.
Nelson is correct in that the first resistors constitute RC rolloff of secondary/rectifier (transient) excitation currents, but there is nothing to damp oscillations between the individual capacitors, and between the capacitors and the circuit and circuit load.
Lars' version pays attention to this, and this is what I am giving due credit for.
I think most of us have heard tonal/dynamic changes when main caps are paralleled with same value and type, and/or smaller value and different type.
I have heard both of these cases enable subjective sonic/dynamic improvements.
I have also heard both these cases cause subjective sonic/dynamic detriment, and I think this can be largely due to brief decaying resonances in the supply/circuit/load system.
To some ears this may provide subtle or not so subtle response and/or dynamic emphasis and extra 'liveliness', but my ears have long since grown tired of this kind of excitement, and this presents as artificial to me.
These artifacts can also be distinctly un-musical into the bargain, and this is where sonic troubles can start.
A single pair of large and 'dead' (relativlely high esr) caps can indeed be more sonically acceptable than an infinitely fast supply for these reasons.
Running class A by definition puts a big snubber across power supplies.
I did clearly say much earlier in this thread.......
"Ime, taming psu resonances is always a sonically good thing.
Eric."
These observations apply mostly to class B stages (line and/or power amp/reactive speaker) where there is more opportunity for abrupt current transitions to excite and/or sustain any electrical resonances in the system.
.......just some of my views and experiences for now...........
Eric.
Hi Frank....and Nelson........fdegrove said:Hi,
Yes indeed...
It's the exact same thing.
Cheers,
I beg to differ that these are not quite the same thing.......
Directly paralleled capacitors do not have external damping between them, and are free to interact according to the parasitic characteristics of each.
This interaction can cause supply/circuit/load resonances that may or may not be present all the time, and may be transiently triggered by supply or circuit or load characteristics/parasitics, or all three.
Nelson is correct in that the first resistors constitute RC rolloff of secondary/rectifier (transient) excitation currents, but there is nothing to damp oscillations between the individual capacitors, and between the capacitors and the circuit and circuit load.
Lars' version pays attention to this, and this is what I am giving due credit for.
I think most of us have heard tonal/dynamic changes when main caps are paralleled with same value and type, and/or smaller value and different type.
I have heard both of these cases enable subjective sonic/dynamic improvements.
I have also heard both these cases cause subjective sonic/dynamic detriment, and I think this can be largely due to brief decaying resonances in the supply/circuit/load system.
To some ears this may provide subtle or not so subtle response and/or dynamic emphasis and extra 'liveliness', but my ears have long since grown tired of this kind of excitement, and this presents as artificial to me.
These artifacts can also be distinctly un-musical into the bargain, and this is where sonic troubles can start.
A single pair of large and 'dead' (relativlely high esr) caps can indeed be more sonically acceptable than an infinitely fast supply for these reasons.
Running class A by definition puts a big snubber across power supplies.
I did clearly say much earlier in this thread.......
"Ime, taming psu resonances is always a sonically good thing.
Eric."
These observations apply mostly to class B stages (line and/or power amp/reactive speaker) where there is more opportunity for abrupt current transitions to excite and/or sustain any electrical resonances in the system.
.......just some of my views and experiences for now...........
Eric.
Lars Clausen said:
Sorry for coming in so late guys, missed the fun.
The above story assumes that the fact that there is different impedances to each cap, means they will initially charge differently. This is not the case. The charging current will predominantly be determined by the wiring resistance of the transformer secondary and the diode incremental impedance. That lot is MUCH more than a few milliohms. So, at the end of the charging cycle, ALL caps are at the same voltage or at least very, very nearly so.
And even if the effect would exist, it is a very long jump to the sound effects mentioned in the first posts.
I agree with Nelson, mostly crap.
Well, Lars, that's what you get from listening to someone who wants to sell more caps instead of doing your own thinking.
Cheer up.
Jan Didden
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