Questions about phantom filtering caps

[thekid777]

Hi,
I don't know which cap would be best suited for this app and which important parameters it should have.
Original caps are some unknown "samar" branded caps 100/25 - 20mm length and 10mm diameter.
To replace these caps I looked at Panasonic FM which are smaller and I'm not sure if it's a good thing.
I found Elna silmic have the same size but don't know if they are good to use here as I read some people say they can dull the sound?
Thanks for your help!

 

[ruffrecords]

The ones in the picture are regular electrolytics. They cannot be phantom power filtering because their voltage rating is not high enough; unless it is not 48V phantom power.

Cheers

Ian

 

[RuudNL]

It depends. I could imagine that the microphone inputs are transformer coupled and the capacitors are only there as a safety measure.(To prevent core magnetisation due to DC offsets from transformerless microphones.)
But if the intention is to separate the (48 v) phantom voltage from a transformerless microphone input, the capacitors should at least be 50 v. or higher.

 

[Kingston]

I don't know which cap would be best suited for this app and which important parameters it should have.

What app and what parameters? Currently we are only guessing. Show the schematic or trace this section yourself. If it's phantom RC filter then they will have absolutely zero effect on sound, but in that case you should indeed replace them with +50V rated versions. Any bulk cap will do.

When you have no idea what these caps are doing, it's completely pointless to replace them. Also Samar is not some "unknown" brand. It's one of the most widely distributed electrolytic cap manufacturers for consumer applications.

 

[tubegeek]

I think I understand what this panel does - let me try it.

The row of female connectors on the bottom accept mic connections, the row of males on top pass the mic signals through. The resistors supply phantom power to all of the mics and the capacitors block DC from reaching the upper jacks.

If that's the case, then as ruffrecords stated, either the caps are rated for too low a voltage, or the voltage is not standard 48V phantom power.

The part that confuses me and makes me doubt my interpretation, is that there are all those separate leads for every phantom supply connection, two for every pass-through which are shorted together in pairs at the resistors.

What's up with that?

If my interpretation is correct, then those could have all been bused via one (fat) wire, just as all the grounds are.

(Maybe there are on/off switches we can't see for each pass-through's phantom power? Still, why two wires?)