Field spotter's guide to capacitors

[weinstro]

This is hopefully a basic question.

I have some old Marantz amplifiers from 1980 or so that I wish to freshen up a bit.

There are several types of capacitors easily seen on the circuit boards. The technical manual indicates that they are "film" capacitors, and gives the appropriate value, but I'm not sure if these are polycarbonate, mica, tantulum, etc. I generally have no problem spotting electrolytics.

This would be helpful in terms of specifying suitable replacements.

Some look like green chicklets, and some look like a wad of magic tape. Any ideas?

Thanks and regards,

Rob

 

[OliverD]

Besides the value you don't need to know what Marantz put in there originally in 1980 as you will do better anyway. It more depends on the position in the circuit (AC signal coupling, PSU filtering etc.) what type fits best.

I belong to those who think that topology and active devices have the most influence on the sound. For the passive components, I use resonably priced high quality parts, nothing esoteric.

This is my personal capacitor selection guide, based on listening preference and local availability, valid for (pre-)amplifiers and other line level audio circuitry:

For the small electrolytics, I use "Panasonic FC" as I can get them at resonable prices. The bigger values (PSU) are "BC Components", series "154" or "051", sometimes "Roederstein EYS-07".

I don't use tantalum or ceramics in (analogue) audio.

For film type capacitor, my choice is as follows:

Up to about 10nF: Silver Mica, Styroflex (R) or Wima FKP-2, depending on budget and space available.

10 nF to 1µF: Siemens MKH or various Wima types

above 1µF (PSU filtering only): Wima MKP-10

above 1µF (AC coupling): Replace by wire if possible, optionally add DC servo. If not possible, re-design circuit or ask the passive components gurus for a suitable esoteric part.

Hope this helps.