What differences should I expect between say Panasonic (good bang per buck) vs Epcos/Siemens Sikorel capacitors (ie 10,000uF)?
These power supplies (one per channel) are for a Class A amplifier.
Do the capacitors only make a big difference if the transformer is under rated (by the way I am using two 300VA transformers - one per channel)?
What is the most important specification for a power supply capacitor (High Ripple Current, Low ESR, etc)?
These power supplies (one per channel) are for a Class A amplifier.
Do the capacitors only make a big difference if the transformer is under rated (by the way I am using two 300VA transformers - one per channel)?
What is the most important specification for a power supply capacitor (High Ripple Current, Low ESR, etc)?
Hi,thanh1973 said:
if the transformer of a ClassA amplifier is under-rated it will run hot.
A 300VA transformer should be down rated to ~70% when feeding a capacitor input filter. leaving ~200VA as the maximum output from the filter.
If the continuous demand from the ClassA amplifier exceeds 100watts then your 300VA is too small.
Don't ask your transformer to run a continuous load of >50% of capability.
BTW,
25W of ClassA output power will usually require at least 100W of dissipation.
thanh1973 said:
I quote from the page....
"By way of example, a typical commercial value capacitor, rated at 10,000uF/63V and costing some Euro 8-9, will have a speed of 30-40V/uS at best. An equivalent Elna for Audio series black, costing some Euro 15-25, will have a speed in the range of 80-90V/uS, i.e. at the very worst, double the speed of the best case in commercial cap land. A Siemens Sikorel cap, costing some Euro 20-30, will slew at over 100V/uS - but at a price.
And this is hard to ignore if you want good quality sound. What's the use of ultra fast electronics, capable of tremendous speeds, if they will be bogged down by slow capacitors, which will appear as speed limiters? I can't help being sarcastic here - this is why in so many cases the advertised amp speed is never achieved in real life.
Many manufacturers measure the speed of the input stage only, and far too few of the overall amplifier - the second group will always show much less impressive results. So beware of wild figures, they are most probably not truly representative of the amp as a whole, on an input-to-output basis.
"
Hi Nordic,
How does the speed of the cap affect the amplifier?
My uneducated guess is it only changes the time it takes to charge the cap. Does this mean a shorter charging spike with a higher current value? Some people actually put a resistor between the diode and cap to reduce the charging rate.
Can you point me to any threads about this as I can't recall seeing any?
regards
How does the speed of the cap affect the amplifier?
My uneducated guess is it only changes the time it takes to charge the cap. Does this mean a shorter charging spike with a higher current value? Some people actually put a resistor between the diode and cap to reduce the charging rate.
Can you point me to any threads about this as I can't recall seeing any?
regards
surely it's the ability to discharge into the load that control the sound effect. The recharging pulse is an artefact that we should endeavor to reduce if it affects the sound.
Fast discharge (transient current supply) is usually augmented with local decoupling/bypass capacitors to avoid the wire/trace inductance from the physically large electrolytics.
Fast discharge (transient current supply) is usually augmented with local decoupling/bypass capacitors to avoid the wire/trace inductance from the physically large electrolytics.
Just recently I replaced 10 000uF 25V cap in my amp (lame Genius SW-5.1 HT) and instead of bad cap CapXon I used Samxon KM. Works great. For the 35V one I used Nichicon VR ones.
Samxon KM 10 000uF 25V has ripple 2500mA (d18 - what I need)
Nichicon VR 10 000uF 25V has ripple 3000mA (d20, 85°C only)
Panasonic TS-HA 10 000uF 25V has ripple 3000mA (d22)
http://www.samxon.com/upload/products/standard/prodPDF_31.pdf
http://www.nichicon.co.jp/english/products/pdf/e-vr.pdf
http://www.panasonic.com/industrial/components/pdf/PIC_aec_ts-ha-hb.pdf
Samxon KM 10 000uF 25V has ripple 2500mA (d18 - what I need)
Nichicon VR 10 000uF 25V has ripple 3000mA (d20, 85°C only)
Panasonic TS-HA 10 000uF 25V has ripple 3000mA (d22)
http://www.samxon.com/upload/products/standard/prodPDF_31.pdf
http://www.nichicon.co.jp/english/products/pdf/e-vr.pdf
http://www.panasonic.com/industrial/components/pdf/PIC_aec_ts-ha-hb.pdf
So is everything else on these forums (ie heresay/anecdotal story).
One mans opinion is as good as anothers.
The fact that the person has gone to the effort of trying these capacitors, and writing up his observations, deserves more respect than you have given the person. I doubt very much that you have actually tested/tried this amount of different capacitor or anyone else here for that matter.
Anyway, what I found interesting was that he observed that the best results were obtained from capacitors with low tan delta values, while the other specifications were almost irrelevant.
thanh1973 said:
There is a lot on this forum that is not just one man's opinion. Serious people do a lot of investigation, backing up their methods and results. That means you can trust those results, that they give the same results when you do them. They will also be valid *for you*.
There has a been a lot of serious investigation on, for example, gravity, to the point that if you go to any garden, and drop any apple, you can be pretty sure it falls down. This is not 'just any man's opinion'.
If I increase the power supply voltage for my amp, it will deliver more output power. The same happens with your or anybodies amp. Not just 'any man's opinion', but serious engineering.
I have no disrespect for anyone. But listening to a bunch of components and reporting preferences as if it is a serious investigation borders on the misleading. Heck, we don't even know if the guy actually did have those caps and even did listen or not. And please, don't accuse me of accusing someone of lying. I'm just pointing out that it is anecdotal, a story, which may be true, untrue, a bit true or anything in between. Even if true, it may or may not or may be partly valid for you.
Don't confuse anecdotes with serious testing.
Edit: Not everything is just 'anyman's opinion'. You can't build safe cars based on 'anybody's opinion. You can't fly planes safely or go to the moon based on 'anybody's opinion'. Audio is not that critical, of course, but there IS a difference between 'anybody's opinion' and solid, valid, documented, repeatable engineering and research that brings you somewhere.
Edit 2: You remember that claim of 'fast slewing 10.000uF caps'? THAT, my friend, is 'anybody's opinion' and totally hogwash. Apart from the fact that nobody bothered to calculate how much current you need to slew 10.000 uF at 40/usec (400.000 amps), apparently nobody did some basic thinking to realise that the purpose of supply caps is NOT to slew, but to keep a voltage that is as constant as possible.
Why are you here if you refuse to do your own basic thinking?
Jan Didden