I need 220/16V quality bipolar capacitor, I need them for Leach amplifier, 4.5. and I cant finde them in Croatia, and Farnell and RS, have only poor quality Nitai... Leach seed it is better to use bipolar, but you can put two regular i serial, I am worry of bas response if I use two 330uF i serial, it is only 165uF, and people complaining of week bas on regular value......., best capacitor I can find is Rubycon ZA, and I think it is bether to use two quality polarized capacitors then poor quality bipolar.....
"people complaining of week bas on regular value......."
The absolute value really doesn't matter. Even with your values the pole will be less than 1hz.
I always run an input filter at a point where the speakers need to be cut-off. Then I change the pole in the feedback loop to a higher frequency than the pole formed by the power supply and the speakers. This makes everything sound better, protects the speakers, especially during clipping. Flat response to DC is not needed nor desirable.
The absolute value really doesn't matter. Even with your values the pole will be less than 1hz.
I always run an input filter at a point where the speakers need to be cut-off. Then I change the pole in the feedback loop to a higher frequency than the pole formed by the power supply and the speakers. This makes everything sound better, protects the speakers, especially during clipping. Flat response to DC is not needed nor desirable.
the bipolar cap is for C6 according to me if you are using 2 polarised cap the midpoint should be connected with a high value resistor ( 1 M ohm ) to a point with a dc voltage to keep capacitor polarised, common point between D13 & D14 if midpoint between cap is positive.
unfortunatly it will add ac current in D14 but should be low very low
This is my idea but should wait second advice........
unfortunatly it will add ac current in D14 but should be low very low
This is my idea but should wait second advice........
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Pinco, you have asked me this in another forum.
My advice: up to some 1.2-1.4V all electrolytics behave as bipolars - this is from a document from Nippon Chemicon, so as it were, from the horses mouth
In your configuration, this cap should only see millivolts, unless the output blows up (at which point it won't matter eather way). My advice would be to use a regular polarised cap, the best you can find, AND the highest value you can fit. Orient it so that the offset voltage corresponds to the polarity, If you are not sure of the offset polarity, you can orient it as you like, then measure the actual polarity, and correct orientation as needed. Also, use two diodes in series (1N4148 or similar) across the cap in anti-parallel (from - to +).
Unless you are using a special cap (like low ESR for switchers or specialised audio cap), use a voltage rating of 25 to 63V. The best way to decide is to check the manufacturer data to see which voltage rating at a given capacitance you need (so a few 100 uF) has the lowest ESR. There is a sweet-point and it is usually between those two voltages but it also depends on the actual capacitance (more actually on the order of magnitude of the capacitance). The reason for using a high value, much higher than would be needed to get clear of the lower end of the audio band, is that you want as little AC component of the voltage on this cap as possible, witin the audio band - when the AC component increases, capacitor distortion sets in. Exagerating the capacitance is a FAR cheaper and effective solution than using a boutique or special cap here!!! That being said, increasing the size of the cap might increase the magnitude of the turn-on 'thump', so unless you are using some sort of protection against this, it is something you need to consider, and if needed adjust by experiment.
My advice: up to some 1.2-1.4V all electrolytics behave as bipolars - this is from a document from Nippon Chemicon, so as it were, from the horses mouth
In your configuration, this cap should only see millivolts, unless the output blows up (at which point it won't matter eather way). My advice would be to use a regular polarised cap, the best you can find, AND the highest value you can fit. Orient it so that the offset voltage corresponds to the polarity, If you are not sure of the offset polarity, you can orient it as you like, then measure the actual polarity, and correct orientation as needed. Also, use two diodes in series (1N4148 or similar) across the cap in anti-parallel (from - to +).
Unless you are using a special cap (like low ESR for switchers or specialised audio cap), use a voltage rating of 25 to 63V. The best way to decide is to check the manufacturer data to see which voltage rating at a given capacitance you need (so a few 100 uF) has the lowest ESR. There is a sweet-point and it is usually between those two voltages but it also depends on the actual capacitance (more actually on the order of magnitude of the capacitance). The reason for using a high value, much higher than would be needed to get clear of the lower end of the audio band, is that you want as little AC component of the voltage on this cap as possible, witin the audio band - when the AC component increases, capacitor distortion sets in. Exagerating the capacitance is a FAR cheaper and effective solution than using a boutique or special cap here!!! That being said, increasing the size of the cap might increase the magnitude of the turn-on 'thump', so unless you are using some sort of protection against this, it is something you need to consider, and if needed adjust by experiment.
ilimzn said:Pinco, you have asked me this in another forum.
My advice: up to some 1.2-1.4V all electrolytics behave as bipolars - this is from a document from Nippon Chemicon, so as it were, from the horses mouth
In your configuration, this cap should only see millivolts, unless the output blows up (at which point it won't matter eather way). My advice would be to use a regular polarised cap, the best you can find, AND the highest value you can fit. Orient it so that the offset voltage corresponds to the polarity, If you are not sure of the offset polarity, you can orient it as you like, then measure the actual polarity, and correct orientation as needed. Also, use two diodes in series (1N4148 or similar) across the cap in anti-parallel (from - to +).
Unless you are using a special cap (like low ESR for switchers or specialised audio cap), use a voltage rating of 25 to 63V. The best way to decide is to check the manufacturer data to see which voltage rating at a given capacitance you need (so a few 100 uF) has the lowest ESR. There is a sweet-point and it is usually between those two voltages but it also depends on the actual capacitance (more actually on the order of magnitude of the capacitance). The reason for using a high value, much higher than would be needed to get clear of the lower end of the audio band, is that you want as little AC component of the voltage on this cap as possible, witin the audio band - when the AC component increases, capacitor distortion sets in. Exagerating the capacitance is a FAR cheaper and effective solution than using a boutique or special cap here!!! That being said, increasing the size of the cap might increase the magnitude of the turn-on 'thump', so unless you are using some sort of protection against this, it is something you need to consider, and if needed adjust by experiment.
Thanks everybody on answers....
I have question for Ilimzn, on Croatian, sory....
Nije mi jasno, Sad san gleda, kod Rubicon ZL koji je visestruko jeftiniji od ZA, najmanja je impedanca mireno pri 100khz, kod 470uF je na 35V i iznosi 0,023 ohma, dok je kod ZA na 16V 0,025, jel si mislija na to??, zašto uzet veæi kapacitet kondenzatora??, kazu da je zvuk mutniji ako se uzme veca vrijednost, mislin kazu, ja se nerazumin tolko....., nisan dobro svatija šta oæeš reæ pa te pitan na domaæem,
"the bipolar cap is for C6 according to me if you are using 2 polarised cap the midpoint should be connected with a high value resistor ( 1 M ohm ) to a point with a dc voltage to keep capacitor polarised, common point between D13 & D14 if midpoint between cap is positive."
This is good advise if the DC source is a battery.
Since the feedback point is the inverting input to the amplifier, any noise and/or hum will be amplified. In practice this sounds worse (unless using a battery), try it and see.
"That being said, increasing the size of the cap might increase the magnitude of the turn-on 'thump', so unless you are using some sort of protection against this, it is something you need to consider, and if needed adjust by experiment. "
Music is not symetrical. Having the pole in the feedback loop being very low will cause poor settling time on musical transients, particularly when the amp is driven hard. This is made worse by feedback, and the fact that the power supplies cannot be perfectly regulated. There is an article at the ESP website discussing this. Clamp diodes help, but do not do any more than limit the off-set.
One solution is the double integrator (servo) used by Crown in their VZ5000 amplifier. The schematic is on-line in their Legacy amplifier schematic library.
This is good advise if the DC source is a battery.
Since the feedback point is the inverting input to the amplifier, any noise and/or hum will be amplified. In practice this sounds worse (unless using a battery), try it and see.
"That being said, increasing the size of the cap might increase the magnitude of the turn-on 'thump', so unless you are using some sort of protection against this, it is something you need to consider, and if needed adjust by experiment. "
Music is not symetrical. Having the pole in the feedback loop being very low will cause poor settling time on musical transients, particularly when the amp is driven hard. This is made worse by feedback, and the fact that the power supplies cannot be perfectly regulated. There is an article at the ESP website discussing this. Clamp diodes help, but do not do any more than limit the off-set.
One solution is the double integrator (servo) used by Crown in their VZ5000 amplifier. The schematic is on-line in their Legacy amplifier schematic library.
Ilmzn wrote:-
My advice: up to some 1.2-1.4V all electrolytics behave as bipolars - this is from a document from Nippon Chemicon, so as it were, from the horses mouth
In your configuration, this cap should only see millivolts, unless the output blows up (at which point it won't matter eather way). My advice would be to use a regular polarised cap, the best you can find, AND the highest value you can fit. Orient it so that the offset voltage corresponds to the polarity, If you are not sure of the offset polarity, you can orient it as you like, then measure the actual polarity, and correct orientation as needed. Also, use two diodes in series (1N4148 or similar) across the cap in anti-parallel (from - to +).
This is a solid piece of advice - I have used it many times and it works well. As mentioned earlier, dont forget to bypass this cap with a good quality film or stacked foil cap of around 1uF. I usually use a 1000uF 16V in parallel with a 1uF 100V stacked foil.
WRT servo's . . . . they are also not perfect - so its a case of choosing your poison.
My advice: up to some 1.2-1.4V all electrolytics behave as bipolars - this is from a document from Nippon Chemicon, so as it were, from the horses mouth
In your configuration, this cap should only see millivolts, unless the output blows up (at which point it won't matter eather way). My advice would be to use a regular polarised cap, the best you can find, AND the highest value you can fit. Orient it so that the offset voltage corresponds to the polarity, If you are not sure of the offset polarity, you can orient it as you like, then measure the actual polarity, and correct orientation as needed. Also, use two diodes in series (1N4148 or similar) across the cap in anti-parallel (from - to +).
This is a solid piece of advice - I have used it many times and it works well. As mentioned earlier, dont forget to bypass this cap with a good quality film or stacked foil cap of around 1uF. I usually use a 1000uF 16V in parallel with a 1uF 100V stacked foil.
WRT servo's . . . . they are also not perfect - so its a case of choosing your poison.
yes, but I was advised to arrange the PSU pole to be lower frequency than the NFB pole and it to be lower frequency than the input filter pole.Andy L. Francis said:
This helps ensure that the next criteria mentioned by Bonsai is also met (low AC voltage across the NFB cap) and D. Self who identified severe distortion on low frequency signals if the NFB pole is set too high.
+-10mF per 4ohm channel gives 40mS RC time constant. This is compatible with an input filter of about 20mS and cuts the low bass response. Try input @ 90mS and NFB @ 130mS and PSU @ 180mS (+-45mF for each 4ohm channel)
boy its hard to get new, objectively proven ideas into peoples heads, Bateman's "Capacitor Sound" series is going on 5 yrs old now:
any film, even mylar is lower distortion than any electrolytic but dc blocking caps are usually large so Al electros are commonly used
Cyril Batemann measured capacitor distortion in his "Capacitor Sound" series in EW/WW - his recommendation for large values is non-polar electrolytics - series plolar back-to-back should be considered obsolete on low distortion grounds, Batemann found some advantage to going to 2 series non-polar Al electrolytics when blocking several V
I have measured low frequency distortion while exploring a sony ce-775 sacd player - surprisingly the main L-R channels with Nichicon Muse series caps actually had more low frequency distortion than the surround channels which used lower spec Nichicons
Doulas Self also has measured Al electrolytic coupling/dc blocking cap distortion and recommends oversizing them - by making the RC time constant large enough the distortion in the audio band drops
any film, even mylar is lower distortion than any electrolytic but dc blocking caps are usually large so Al electros are commonly used
Cyril Batemann measured capacitor distortion in his "Capacitor Sound" series in EW/WW - his recommendation for large values is non-polar electrolytics - series plolar back-to-back should be considered obsolete on low distortion grounds, Batemann found some advantage to going to 2 series non-polar Al electrolytics when blocking several V
I have measured low frequency distortion while exploring a sony ce-775 sacd player - surprisingly the main L-R channels with Nichicon Muse series caps actually had more low frequency distortion than the surround channels which used lower spec Nichicons
Doulas Self also has measured Al electrolytic coupling/dc blocking cap distortion and recommends oversizing them - by making the RC time constant large enough the distortion in the audio band drops
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