Trouble finding Ceramic Capacitor for MS30 Crossover

[Grant1969]

Hi All, new member here hoping someone can help me with suggesting a replacement ceramic cap on my Mordaunt Short crossovers.

I bought the MS30's at a garage sale and found one of the drivers had very low bass reproduction. Testing the main terminals returned a value of about 200 ohms. The driver tested at about 6 ohms so process of elimination, I found one of the ceramic caps on the crossover was 194 ohms.

I have not been able to identify what type of ceramic cap it is, the capacitance or voltage. I tried measuring the capacitance of the good cap on the other crossover (out of circuit of course) but the value jumped around a lot so I took it to the local electronics store but they too were unable to help. The guy said the value of the cap 'might be' 450,000 pF from the markings but it could also be a manufacturers code.

I have attached photos of the crossover and a close up of the cap. If anyone has advice, I'd gladly hear it.

 

[Lojzek]

Manufacturers use such devices (ptc) to protect the drivers from being fried because of too high a current, so these present a significant resistance once they get triggered. 90 could mean the holding current is 900mA.

 

[amplidude]

Aren't those thermistors for protecting the speakers?.

 

[amplidude]

Lojzek was faster🙂

 

[amplidude]

If you plan no abuse ,you can just short them

 

[amplidude]

The big one 0.9 amp . Small one 0.5 a

 

[Grant1969]

Sincere thanks to all who offered advice. Now I can repair the crossover 🙂

 

[system7]

And rest secure in the knowledge that your speakers were designed by Mr. Robin Marshall:

Robin Marshall: A Modicum of Genius | Stereophile.com

One of the audio greats, IMO. 😀

Or maybe a few years after he left MS. But still a satisfying lingering legacy of greatness.