High cap ceramic capacitors.... how they "sound"

[rinox]

Hi, I wold like to test this new kinf of ceramic capacitors as replacement of classic polestyrene caps... anybody have tried that? I know that paper-oil is absolutely the best but they cost a lot and are quite big. I would like to know how do you think about, thanks.

[DF96]

What new kind of ceramic cap? You have not said.

[Ouroboros]

What is the dielectric? If they are 'High Cap' then I guess they are Y5V or Z7U. (Perhaps X5R if you are lucky). The Y5V and Z7U dielectrics especially have a permittivity that falls off quickly with applied voltage, so if the audio signal causes a significant voltage across the cap, as it might do in a C-R coupling network at low frequencies, the harmonic distortion can be considerable.

As you're talking about replacing polystyrene caps, then the capacitance values will be fairly low, so C0G or NP0 ceramic dielectric parts can be used. Unlike the higher-K dielectrics, C0G and NP0 caps are very good indeed, but big and expensive for anything over 10nF.

[indianajo]

I've used cheap Z5U dielectric, expensive 50 V aerovox ceramics to replace tantalum and electrolytic caps between 1 uf and 10 uf. John Curl tells me this is really stupid. Since I'm putting 1 VAC on a 50 V cap going into my ST120, I don't think the non-linearity is hurting me. It sounds pretty good, indistinguishable from the cap free (signal path) CS800s on solo piano records.Sounds better than the all tube ST70 with new output tubes. The tantalum input caps I replaced on the ST120 were themselves a 1985 replacement, and had frying pan noises from the day I installed them. I've owned 8 tantalum caps, and 7 were bad. Wonder why JC and I differ in opinion on them? I used the Aerovox's for coupling and bypass caps on organ preamps where polyester wouldn't fit instead of the 25 year old aluminum electrolytic cap. No issues, especially not the dreaded, much warned against, microphonics. Aerovox 10uf sound a lot better, have better bass & trebel, than the dried up 42 year old electrolytics I replaced. I used 50V caps not because of the 25 mv signal, but because Hammond used them for their 25 mvac signal - maybe they were afraid of static voltage from their rotating disk tone generator? Hint- Aerovox gold ceramics cost over $5 each for 5-10 uf and are made in Mexico.