Capacitor type question .. !

[JPGraphX]

Hi,

I had a hard time to find 820pf and 390pf caps, I found some, could you tell me if this is ok? (they are in a circle on my pictures)



They are Xicon Film Capacitors STYRENE 50V 390PF and Xicon Film Capacitors STYRENE 50V 820PF

Thanks!
JP

[GibsonGM]

They should be fine provided they are rated higher than the voltage present in the circuit.  Is this a 9V circuit?  They will be fine then!

The main difference between capacitors is in their construction...the old ceramic type can be noisy and change their value with applied voltage, so many don't like them in audio circuits.  The poly types are good for all-around use, IMO.  Some think they can be a little 'too clean', but they are fine by me.  Let your ears be the judge! 

Electrolytics are for power supplies, sometimes useful for big coupling caps if that's what you have. Voltage is more critical to them (being close to their rating so they are 'worked').  And you need to watch their polarity.

Rock on )

[R.G.]

Those are polystyrene by their overall appearance. As long as they are enough voltage and are the correct values, they're fine.

Polystyrene are high quality capacitors by most measures of capacitor quality.

[amptramp]

The main use of polystyrene is in circuits where the capacitance should not vary all that much over the temperature range.

[PRR]

It is VERY easy to damage PolyStyrene by soldering and unsoldering.

I would not bet on being able to recover styrenes from a board. Especially butt-mounted like that.

390pFd is a VERY common value.

In nearly any audio situation, 470pFd will work for 390pFd. And 1000pFd (or two 470pFd) for 820pFd.