Vintage caps

[BucketInABucket]

I'm aware that it's generally a good idea to replace the electrolyte and paper caps in vintage amps, but what about the solid aluminium ones? I need them in 0.47uF 25V or better and 3.3uF 6.3V or better but I can't seem to find a modern equivalent for them. Is it even necessary to replace those? They're referred to as aluminium solid in the service manual, while the normal leaded radial electrolytics are referred to as electrolytic tubular so I don't think they're normal electrolytics. They also look different and have different branding to the electrolytics: everything electrolytic is elna while the 'aluminum solid' caps are CSY-branded.

 

[nigelwright7557]

The solid caps can last 5 to 20 times longer than wet electrolytics.

 

[BucketInABucket]

Would it be fine to replace them with equivalent-value polypropylene caps?

 

[rayma]

Would it be fine to replace them with equivalent-value polypropylene caps?

That should be ok. Where are they in the circuit?

 

[phase]

Depending on where they are, the added inductance of a film cap may not be the best thing.
They most likely are not degraded, as mentioned these last a long time.

 

[BucketInABucket]

It's a Kenwood KA-6000. Schematic is available on Kenwood KA-6000 - Manual - Solid State Stereo Amplifier - HiFi Engine. I've no idea how to trace the signal path, but I do know where the solid caps are.