RFI RC filter

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Rob Flinn

Well-known member
Joined
Jun 3, 2004
Messages
5,207
Location
Between Sussex, UK & Aude, France.
I have a QUAD 44 hifi preamp on the bench at the moment which has a popped RFI filter capacitor thingee.  See pic. 

I don't seem to be able to find one that is this exact same spec 47n/1K from my usual suppliers. 

1. Is the spec particularly important ?
2. Is the filter itself particularly important ?  Will the owner notice a difference if I just leave it out ?
 

Attachments

  • supressor.jpg
    supressor.jpg
    567 KB · Views: 25
Is that one of the infamous RIFA capacitors/filters, that always 'explode' after some time?

I just looked at the schematic of the Quad 44 power supply, but I don't see this component.
 

Attachments

  • Quad44PSU.PNG
    Quad44PSU.PNG
    60.9 KB · Views: 20
Looks indeed like one of those doomed-to-fail metallized paper ones.

Just about any X2 rated cap of the same value should do fine. Assuming that's an RF-filter on the mains input?

RuudNL said:
Is that one of the infamous RIFA capacitors, that always 'explode' after some time?
 
RuudNL said:
Is that one of the infamous RIFA capacitors/filters, that always 'explode' after some time?

Definitely is. Seems like they all burst open along the same axis. I’ve collected all of the ones I’ve replaced just for grins and they all physically look like this, with the split horizontally across one side.

A lesson in the importance of material selection. The resin they used was rigid and lacked the flexibility needed for temp-related expansion and contraction. Over time, a hairline crack develops, moisture comes in and BOOM. Out comes the (nastiest smelling) white smoke.
 
Back
Top