Need help identifying this cap

[snorkelmonkey]

Hey guys thanks for having me aboard!

I'm restoring an Alesis Midiverb II, and most of it's original issues sorted out but still have a few left.

I ran across some info that the decoupling caps in these units were problematic. I'm trying to find out what type they are. They're mostly .1uf (104). Can't make out the manufacturer?

Here's a photo I found online that looks identical to the types in this unit. I would like to replace them with a better made cap (any suggestion would be greatly appreciated) of the same type to keep the original tone of the unit in tact. TIA

[Th3_uN1Qu3]

Re: Need help identifying this cap

They are polyester (film) caps. It doesn't really matter who makes them, they are high quality caps to be used in signal coupling applications (audio or radio frequency). Just look for "polyester capacitor" or "metallized film capacitor" and you will find what you need. The metallized film type are the best.

[snorkelmonkey]

Re: Need help identifying this cap

they are high quality caps to be used in signal coupling applications (audio or radio frequency).

Really? In all the searches I made one of the chief suspects they claim are these blue caps. Known to fail (short) in these units.

[Agent24]

Re: Need help identifying this cap

Do they say why?

Is it the capacitors themselves or is the circuit tough on them?

[snorkelmonkey]

Re: Need help identifying this cap

Do they say why?

Is it the capacitors themselves or is the circuit tough on them?

The unit must be about 24 years old. Some of them look to have a large C with an M inside it followed with 104 all on one line. The line below that reads M S E.

Other caps just have .1M on them. All are blue and look like the caps in the photo above.

What's interesting is they use those little WIMA box caps in other parts of the circuit. I would think they would have used those for the entire circuit if these blue caps are poly's?

[kc8adu]

Re: Need help identifying this cap

could also be multilayer ceramic.
odd because tantalums are the ones that tend to short and even burn up.

[Th3_uN1Qu3]

Re: Need help identifying this cap

104 means the same as .1 which is 100nF or .1uF whichever way you want to call it. All blue caps i've seen are polyester, except the Y caps in power supplies which are ceramic, but those have a different appearance.

Ceramic caps are generally not welcome in audio because they tend to act as microphones.

[snorkelmonkey]

Re: Need help identifying this cap

could also be multilayer ceramic.
odd because tantalums are the ones that tend to short and even burn up.

I ruled out tantalum's, no polarity markings on the caps or the circuit board's screen printed layer (on the board all the electrolytic caps are marked for polarity). I wondered if they could be multilayer ceramic's?

Anyone know what company uses/used that CM logo? That might help narrowing it down?

[eddie97044]

Re: Need help identifying this cap

The C with small M could stand for Cera-Mite which is now owned by vishay semiconductor. They make ceramic capacitors I guess.