The idea of paralleling big capacitors by smaller ones has been propagated in the mid of the 1980ies by a German stone, erm, guy, right? He had decided to do this at each capacitor, even film caps in the µF range were paralleled by others of some ten nF's. Presumably he did this to attract clueless audiophools to his products.
Seems that he has, and also the audiophools have, forgotten about the dozens of electrolytics the audio signal has passed through in any mixing console, right before getting banned to record or to disc. It's quite simple: What you don't see, you don't hear.
Best regards!
Seems that he has, and also the audiophools have, forgotten about the dozens of electrolytics the audio signal has passed through in any mixing console, right before getting banned to record or to disc. It's quite simple: What you don't see, you don't hear.
Best regards!
But surely using a bypassed cap at home can undo all the damage done by all those nasty electrolytics in the studio?
This is why I prefer to listen to 1950's mono recordings wherever possible, for a pure uncorrupted signal devoid of the influence of an unknown (I suspect very large) number of (probably)unnecessary electrolytic (and other types I imagine) capacitors, not to mention all the op amps with their innumerable (I haven't tried to count them) transistors.
1992 called and asked for their recording studio truisms back. It's almost like AVB, Dante, etc. never happened. The majority of modern consoles are controllers that don't pass analogue audio, or sometimes audio at all. Producers often insist on old analogue consoles on the basis of their proclaimed distinctive sound, hardly an argument for the sonic neutrality of those desks. And it's been common practice to push the A/D as far up the chain as possible forever.
In RF it is customary put several capacitors in parallel to decrease the total impedance, moreover when high BW is required, or high power is to be handled in the circuit, so the lower value capacitors with higher resonant frequencies bypass the larger ones as soon as they become inductive over its self resonant series frequency. Similar approach is used in SMPS's or where high current pulses are present.
But I believe that to do such a thing in audio is useless.
But I believe that to do such a thing in audio is useless.
Paralleling coupling caps was done in the eighties and nineties by many brands. Electrolytic caps were different then. Film caps were way too large too and large value film caps were non existent anyway.
Now I would check if the load really is 10 kOhm. If it is higher I would calculate and choose a large value film cap that fits on the PCB. No deterioration over time, bipolar and better sounding than most electrolytic caps. Carefully check the circuit as I have seen devices with 100 µF (or even higher value) caps with a GND reference resistor of 10 kOhm....
Despite the comments of many professors here paralleling a 100 µF electrolytic coupling cap with a small value film cap can be detected by ear immediately. Not sure if that is a good or bad thing. As professors lack time because they are calculating the whole day they don't have the time for such frivolous experiments. It won't hurt the world to try it out just for the sake of the experiment as influence in theory is neglectable. Practice might differ from theory. IMO using a single good quality (preferably film) cap makes more sense. I stock 100 µF MKS caps so I can assure you they exist.
It comes down to avoid electrolytic coupling caps where possible which is fully possible with film caps as they have shrunken to acceptable sizes. Even if the signal went through hundreds of electrolytic caps in the mixing console and studio... you can't change that. You do have the chance to make your device not mistreating the already hampered signal any more 😉 As the device is from 1992 a cap change is not luxury so combining necessity and quality seems a good choice.
Now I would check if the load really is 10 kOhm. If it is higher I would calculate and choose a large value film cap that fits on the PCB. No deterioration over time, bipolar and better sounding than most electrolytic caps. Carefully check the circuit as I have seen devices with 100 µF (or even higher value) caps with a GND reference resistor of 10 kOhm....
Despite the comments of many professors here paralleling a 100 µF electrolytic coupling cap with a small value film cap can be detected by ear immediately. Not sure if that is a good or bad thing. As professors lack time because they are calculating the whole day they don't have the time for such frivolous experiments. It won't hurt the world to try it out just for the sake of the experiment as influence in theory is neglectable. Practice might differ from theory. IMO using a single good quality (preferably film) cap makes more sense. I stock 100 µF MKS caps so I can assure you they exist.
It comes down to avoid electrolytic coupling caps where possible which is fully possible with film caps as they have shrunken to acceptable sizes. Even if the signal went through hundreds of electrolytic caps in the mixing console and studio... you can't change that. You do have the chance to make your device not mistreating the already hampered signal any more 😉 As the device is from 1992 a cap change is not luxury so combining necessity and quality seems a good choice.
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Leading analog designers like Bruce Hofer of Audio Precision are already a step ahead: ceramic COG/NPO SMD capacitors are by far the best, because of their small size and lack of connecting wires, iron/copper or otherwise.
The only drawback is that they are not available yet in (very) values.
Jan
The only drawback is that they are not available yet in (very) values.
Jan
Try to find a 100 µF 25V C0G SMD cap and I will be the first to try them out. I am not so sure if those C0G are just as good as SMD film caps in the same value. Ceramic caps are the weapon of choice as the industry has chosen that format and I doubt these people even listen to what they produce as audio is not so much in their interest. Apart from that finding SMD film caps in large values is also a challenge and prices are non competitive to those of ceramic caps. Even non leading audio engineers will acknowledge that X7R etc. are not the best in audio. So choosing the best of ceramic dielectrics (currently C0G) is the maximum obtainable in the near future. Low weight, small size and thus low price are key parameters.
In Through Hole the situation is very clear which dielectric performs more optimal (for those that listen to equipment). Many of my audio pals are convinced: the larger the part the better it is 🙂
It may not be a surprise but I like parts to be good and small.
In Through Hole the situation is very clear which dielectric performs more optimal (for those that listen to equipment). Many of my audio pals are convinced: the larger the part the better it is 🙂
It may not be a surprise but I like parts to be good and small.
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It is quite plausible that adding a bypass is audible. It is less likely that it is a good thing.jean-paul said:
In older gear that had older normal electrolytic caps it was considered a good thing (apparently) as it was done in many devices. Even triple bypasses.
There is a strong herd instinct among audio designers, supported by audio journalists and some customers.
J-P. diyralf, you are behind the times. They are now used in equipment used to test and judge audio stuff.
Ceramic COG and NPO SMDs are no longer the junk of even 5 years ago and can hold their own, soundwise, with the best of the old, expensive and huge film cap clunkers.
But this shift has happened unnoticed except by those who are always looking for the best parts and understand the issues. There is little doubt that Bruce Hofer is one of or even the world recognized authority for exceptionally linear and transparent designs, so if he switches to SMDs, we should pay attention.
So far, you can't get them for values above a few uF, but that means that they can already fill a lot of spots in our best designs.
Jan
Ceramic COG and NPO SMDs are no longer the junk of even 5 years ago and can hold their own, soundwise, with the best of the old, expensive and huge film cap clunkers.
But this shift has happened unnoticed except by those who are always looking for the best parts and understand the issues. There is little doubt that Bruce Hofer is one of or even the world recognized authority for exceptionally linear and transparent designs, so if he switches to SMDs, we should pay attention.
So far, you can't get them for values above a few uF, but that means that they can already fill a lot of spots in our best designs.
Jan
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Given their additional exceptional mechanical stability it wouldn't surprise me, circuit depending, if they better the clunkers.
I'm sure you understand why that will not impress some people? In fact, for them it might even explain something!jan.didden said:
Sorry but I am not behind times. I am not contradicting your statements. I never said C0G to be junk as they are the best in ceramic caps. I do say that most other ceramic caps are not the best one can find. I also did say that I doubt if C0G can compete with the best in film caps as they simply can't (not being self healing being one of the issues). It does not matter as the market pushes to SMD and cheap. Of course manufacturers will choose the parts that are small and cost effective. Even if they know a 10 µF MKP will do better they won't use it as it is expensive, large and TH. TH is not even considered in new designs except for power electronics like frequency converters, motor controllers etc. I know my hardware.
Also the shift did no go unnoticed, did you even read my post ?
I don't care if it is a deity that chooses for SMD C0G or whatever variant as everybody will be forced to do so. Then logic tells us to better pick out the best what is available (just like we did when TH was standard). Besides that I make my own choices as you may have noticed. Like many guys in this hobby I don't shy away from any empiric experiment (unlike some naysayers who don't even try out swapping 2 caps) and I don't feel the slightest shame for doing so.
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