With regard to the operating values at this place of the voltage occurring, this is correct. I haven't heard from solid state phono stages (op-amp or discrete) with voltages in this area. Even in tube amps lower voltage occurs.
But in order to get best sonic performance very high voltage capacitors in the RIAA network are better than low voltage, because the heavy wight of such HV caps provide low-microphonic character, especially in high impedance RIAA networks.
Unfortunately such caps are in most cases only suited for new RIAA tube projects due the larger space requirements.
P.S.: The question in post #14 was not this. I want to have the values of tan δ and others of this caps from "db".
I don't understand this term: "They don’t come in high enough precision."
in order to provide low tolerance or low sonic precision while performing a listening test ?
in order to provide low tolerance or low sonic precision while performing a listening test ?
You can always try ex-Soviet K72-7 - they are in a box, so maybe stacked which was last that polystyrene took ( in a internal design form ).
They come in 0,5% - 2,5% @ 250 Vdc.
Small values up to a few nano.
There are S+M stacked orange boxed polystyrene's said to be the best of the bunch.
For RIAA networks.
They come in 0,5% - 2,5% @ 250 Vdc.
Small values up to a few nano.
There are S+M stacked orange boxed polystyrene's said to be the best of the bunch.
For RIAA networks.
@ tief, 450v is good enough. No need to go crazy. Uk ebay has a huge selection currently in the 1n to 30n range, cheap prices too. I stocked up a few months ago.
You need 2% precision or better for accurate RIAA.
Nah, just pad the values with pf sized wima. Buying a big batch and matching is often cheaper than trying to source 1 or 2% parts.
Every designer should consider potential failure pathways in valve amplifiers. While I generally agree with you, it is not wise to use 35V rated capacitors if a potential failure (or lack of valve in a socket) might apply 200V to capacitor.
Of course, 35V capacitors are generally not terribly expensive to replace, but when a capacitor fails in a catastrophic manner the 'smoking amplifier' effect can become overwhelming.
some of your DALE 2317's look like they are flaking enamel... but that might just be cosmetic.
I definitely trim using pf caps. Some like to use polystyrene, but to be frank and honest I find polypropylene and tin foil caps, trimmed with silver mica to yield the best 'sounding' results.
And yes, I know Morgan Jones prefers polystyrene.... Maybe in his amplifiers with his speakers, etc. they work. For me they are a pain and just sound meh...
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Still using technics DJ turntable with ortofon concord pick-up? ok... then styrene caps are fine for RIAA