I'm wondering what the source of impact would be in the typical amp. Striking is certainly more invasive than a low frequency vibration.
I switched to ceramic for cdom over silver mica to see if I could hear or measure a difference. I couldn't find a difference.
I switched to ceramic for cdom over silver mica to see if I could hear or measure a difference. I couldn't find a difference.
Mr Evil,
Many things work, but it`s just not enough. Ceramic is a strongly nonlinear dielectric material causing nasty sounding distortion and is banned by me, no matter what other outstanding properties it might have.
Did you read Mr Bateman's article? You can't lump all ceramic capacitors together like that, some are very linear. There are a number of other similar capacitor distortion test results out there too.Lumba Ogir said:
Conrad,
Well, all things are relative. Physical size is directly proportional to sound quality, no exception to the rule. You should be tremendously suspicious about small-sized capacitors.
i have been doing a lot of reading lately about capacitors and have seen the term non-linear thrown about when discussing tantalum and/or ceramics. I am not exactly sure what people are referring to when they say this.
I think it is important to define the terms well so as to avoid misunderstandings and unnecessary debates.
My reading has led me to believe that one non-linearity people refer to, is the section of the impedance curve where the reactance and the inductance of the cap meet (at the resonant frequency?). Around this frequency there is a non-linear, steep drop off in impedance.
Steep drop offs are a concern because if other caps in the circuit have impedance curves that cross steeply at the same or a similar frequency this can cause oscillation.
My understanding is that if parts or chosen appropriately so as to avoid oscillation the circuit should be good to go.
One final thought is that you can combine less linear caps like some ceramics with other caps to make a flatter (more linear) output impedance curve than you could without them.
I think it is important to define the terms well so as to avoid misunderstandings and unnecessary debates.
My reading has led me to believe that one non-linearity people refer to, is the section of the impedance curve where the reactance and the inductance of the cap meet (at the resonant frequency?). Around this frequency there is a non-linear, steep drop off in impedance.
Steep drop offs are a concern because if other caps in the circuit have impedance curves that cross steeply at the same or a similar frequency this can cause oscillation.
My understanding is that if parts or chosen appropriately so as to avoid oscillation the circuit should be good to go.
One final thought is that you can combine less linear caps like some ceramics with other caps to make a flatter (more linear) output impedance curve than you could without them.
although somewhat anecdotal, I suspect that there is some/much evidence to support this contention.Lumba Ogir said:
It means that the current through the capacitor is not a linear function of the voltage across it. So for instance, if you have a nonlinear capacitor in a high-pass filter and put 1kHz into it, you get 1kHz + harmonics out the other side.okapi said:
So how is it that a C0G capacitor, which you say is highly nonlinear, shows no appreciable distortion?Lumba Ogir said:
okapi said:
It wasn't tangential at all. Thanks for posting it 🙂.
If you haven't done so already, check out the downloadable articles at Cyril Bateman's site. He did a boatload of capacitor distortion measurements.
Most ceramics have lots of distortion in the audio band. Just learn how to measure one. Published it more than 30 years ago.
john curl said:
SOME ceramics have very little distortion. Just learn that some have measured them.
"Condemnation without Examination is Prejudice"
Application counts for a lot.
A capacitor can add no more distortion than the voltage across it when in series or the current through it when in parallel. Very low frequency high-pass filters can afford absolutely terrible capacitors with only a small hit to audio frequency linearity. Likewise very high frequency low-pass filters can tolerate fairly bad capacitors with again a hit, but only a small hit to audio frequency linearity.
I wouldn't build a crossover with most ceramics, but I also wouldn't rule them out from all audio signal applications.
A capacitor can add no more distortion than the voltage across it when in series or the current through it when in parallel. Very low frequency high-pass filters can afford absolutely terrible capacitors with only a small hit to audio frequency linearity. Likewise very high frequency low-pass filters can tolerate fairly bad capacitors with again a hit, but only a small hit to audio frequency linearity.
I wouldn't build a crossover with most ceramics, but I also wouldn't rule them out from all audio signal applications.
Mr Evil,
There is no adequate method to measure sound quality. It`s up to you whether you trust the measurements or your ears.
I'm sorry, this is nonsense. MOST ceramic caps that you can afford, have significant measurable and listenable distortion. There are FEW exceptions and the good ceramic caps can be expensive for anything over 1000pf.
You may accuse the C0G capacitors of being inadequate in some way, but it can't be anything to do with their linearity. If there is something else that is causing an audible effect that does not show up in the normal measurements, then it will show up in a double-blind listening test. I am not aware of any such test ever showing an audible difference. I have personally listened (sighted) to many circuits using a variety of capacitors, and never noticed anything wrong with C0G ceramics.Lumba Ogir said:
- Status
- Not open for further replies.