Cornell Dubilier 940C / 0.01uF 500Vac (3,000Vdc) - 10% tolerance.
Technical specifications (according to manufacturer): "Type 940 round,
axial leaded film capacitors have polypropylene film and dual metallized
electrodes for both self healing properties and high peak current
carrying capability. This series features low ESR characteristics,
excellent high frequency and high voltage capabilities; high dV-dt for
snubber applications; capacitance range 0.01 to 4.7µF; capacitance
tolerance ±10%; rated voltage 600 to 3000 Vdc (275 to 500 Vac, 60 Hz);
operating temperature range with ripple 55ºC to 105ºC / full rated
voltage at 85ºC - de-rated linearly to 50% rated at 105ºC; insulation
resistance more than 100.000 MO x µF; test voltage between terminals @
25ºC 160% rated dc voltage for 60s; test voltage between terminals &
case @ 25ºC 3kVac @ 50/60 Hz for 60s; life test 2000 h @ 85ºC, 125%
rated dc voltage; life expectancy 60.000 h @ rated Vdc 70ºC; case
material UL510 polyester tape wrap; resin material UL94V-0 epoxy fill;
terminal material tin plated copper."
Sound: Using the 500Vac (3,000Vdc) Cornell Dubilier 940C as a bypass capacitor in the value 0.01uF really is the "icing on the cake" when you are looking for a low cost bypass capacitor that gel's everything into one coherent sound.
Over the past few years I have used these in many different combinations and every time they just added more to the overall sound.
More coherency and more ease. Especially when you have been "cooking" to find your favorite mix of capacitors and only need to cement the different characters together.
Adding the 940C creates an overall more mature sounding speaker.
And no, they are not better than the Duelund Silver Bypass capacitor that excel's in naturalness and richness of tone.
The Duelund is in another league, not only in sound quality but also in price ;-)
The Vishay MKP1837 used to be my favorite low cost bypass capacitor but now it is the Cornell Dubilier 940C / 0.01uF / 500Vac (3,000Vdc).
It surpasses the Vishay with quite some margin :-)
Verdict: use them everywhere!
Vishay MKP1837 / 0.01uF MKP 100Vac (160Vdc) - 1% tolerance.
Technical specifications: Metallised polypropylene, radial capacitor, designed for LC/RC filter circuits, coupling and de-coupling at high frequencies.
Sound: Many years ago I was tipped by Klaus Witte of Germany to try this capacitor as a small parallel cap for the Mundorf MCap Supreme.
I tried them as a parallel cap for the tweeter series caps in my Progress speaker and I must say I was very impressed!
To get straight to the point they don't change a Supreme into a Supreme Silver-Oil but they really do clear things up.
I must admit I was skeptical at first as the value is only 10nF (0.01uF) - and the caps I was using at the time totaled to 12.6uF.
The difference is most noticeable with classical music but also good quality recordings of jazz and fusion benefit.
No change in sound stage width or depth but there is more concert-hall acoustics that let you get into the recording more.
Not as liquid as a Mundorf Silver Oil but they did take away the slightly grainy edge from the Mundorf Supreme's.
A noticeable gain in clarity and transparency making instruments better separable from each other, the violins in an orchestra become a group of individual violins instead of one mass.
Jazz drum brushes sound more like a brush than a "shush".