Hi Thanks for reading It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics. There's a few aluminium electros caps here just underneath the PA5 II input module and also some to its left, is it worth a try ? I don't know what's in the modules as they are potted
The potted modules were the source of troubles with the first edition.
The parallelling of today's electrolytic caps with small film caps seems a habit superseded by the electrolytic caps improved quality.
Changing small value electrolytic coupling caps for film caps and the opamp in the input circuit however.... Improving the 5V switching circuit is maybe worthwhile. It is in other amplifiers, don't know PA5.
https://www.audiosciencereview.com/...ix-d01-module-replacement-for-everyone.44219/
The parallelling of today's electrolytic caps with small film caps seems a habit superseded by the electrolytic caps improved quality.
Changing small value electrolytic coupling caps for film caps and the opamp in the input circuit however.... Improving the 5V switching circuit is maybe worthwhile. It is in other amplifiers, don't know PA5.
https://www.audiosciencereview.com/...ix-d01-module-replacement-for-everyone.44219/
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The caps are not really that good in the first place, would soldering a little 0.1uf wima film cap under the electro upset the circuit
Which caps are not really that good? Rubycon YXF is good. I would pay attention to anything called Capxon and yank em out.
No, it isn't. It highly depends on the circuit and the role of a capacitor in that circuit if bypassing is acceptable or not. If it is beneficial is another story yet. Do you have the schematics for that amplifier or can you trace it out?
Can you give such an example where is NOT acceptable to bypass an electrolytic capacitor with a small one?
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Yes. For example at the output of a regulator. Often lossy electrolytics are preferred there to keep the regulator stable. Bypassing with a small film cap might lead to instability.
Or say you have an external power supply and the final regulator close to the load in the signal part. Also here for decoupling the leads at the input of the regulator a higher ESR cap will be more stable and less prone to negativily interact with the lead inductance.
Or say you have an external power supply and the final regulator close to the load in the signal part. Also here for decoupling the leads at the input of the regulator a higher ESR cap will be more stable and less prone to negativily interact with the lead inductance.
In MOST (well designed) regulators are fine with small caps on the output. And even in YOUR example, a lossy electrolytic will remain lossy with or without a bypass capacitor over it. No stability issues will take place.
Anyway, this is obviously not the asked question here. This thread is not about a bad designed regulator, it's about caps in audio chain, either series with signal or locally decoupling the power supply rails. If you can't say anything useful to a DIY beginner, maybe just don't say anything.
For the OP: Below are some useful readings about this subject.
https://www.analog.com/media/en/training-seminars/tutorials/MT-101.pdf
https://www.analog.com/en/resources...acitor-stabilizing-voltage-the-right-way.html
https://eepower.com/capacitor-guide/applications/coupling-and-decoupling/#
Anyway, this is obviously not the asked question here. This thread is not about a bad designed regulator, it's about caps in audio chain, either series with signal or locally decoupling the power supply rails. If you can't say anything useful to a DIY beginner, maybe just don't say anything.
For the OP: Below are some useful readings about this subject.
https://www.analog.com/media/en/training-seminars/tutorials/MT-101.pdf
https://www.analog.com/en/resources...acitor-stabilizing-voltage-the-right-way.html
https://eepower.com/capacitor-guide/applications/coupling-and-decoupling/#
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???? The OP stated "It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics."
He followed with "There's a few aluminium electros caps here just underneath the PA5 II input module and also some to its left"
It being "caps in audio chain, either series with signal or locally decoupling the power supply rails" so far is your imagination.
He followed with "There's a few aluminium electros caps here just underneath the PA5 II input module and also some to its left"
It being "caps in audio chain, either series with signal or locally decoupling the power supply rails" so far is your imagination.
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Off topic: what do you consider a "bad designed regulator"? Something like a TPS7A470x?
Don't know about this one specific but often these class D amplifiers in small casings have a 5V switcher not giving desired results. Often around the same chinese copied LM2596 IC and often with the same too light/minimum calculated parts. This results then in barely acceptable ripple/noise. Class D amplifiers benefit clearly (audibly) from having a clean power supply voltage and a clean 5V auxiliary voltage for the IC. There is absolute no need to debate this as anyone with a set of ears can connect a clean PSU and conclude in a very short time if that is audible or not.
Laymen often hear or read stuff on the Internet (so it is true) and interpret this like laymen do so not on technical grounds. Like the paralleling of electrolytic caps, replacing already very good opamps, focussing on tiny out of context taken details etc. The normal way is to discover stuff yourself, make a shitload of mistakes, use the instruments not forgetting the ears and not by asking.
Laymen often hear or read stuff on the Internet (so it is true) and interpret this like laymen do so not on technical grounds. Like the paralleling of electrolytic caps, replacing already very good opamps, focussing on tiny out of context taken details etc. The normal way is to discover stuff yourself, make a shitload of mistakes, use the instruments not forgetting the ears and not by asking.
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I'm not exactly a fan of the ASR cargo cult, but given how that Topping gear measures I wonder how what could be improved here. Of course they are also cheap enough to just go for it and slap on a handful of C0Gs and hope for the best that the result will be the desired one.