noisy contact in my Wilco CRS 1047

[stevenrob]

Hello,

I have just received it in very good condition.
But the contact in tape deck makes a little spark when it closes and there is a short big noise in the speakers. Do you have a solution to reduce this noise ?

Best regards

 

[Superduper]

Try adding a non polarized capacitor (ceramic) across the contacts.

 

[stevenrob]

Hello, I have this but it is no ceramic I think. I will look for ceramic capacitor but can you give value ? (V and uf) ?
I also have this : polyester mylar 0.015uF 15nF 100v 5%

 

[Superduper]

All I can suggest is try one and see if it helps, then go a little larger if necessary. Is that an electrolytic? It's probably too large. The polyester one might be better.

 

[stevenrob]

Hello, thanks a lot

I've tried different capacitors but no result. I have another problem : the sound of this boombox. The trebbles are like a porridge ! Horrible, it is hard to hear clearly cymbal.
Can I change the capacitors of speakers ?

Best regards

 

[baddboybill]

Have you checked to see if contacts are even clean? Sometimes dirty contacts will cause a little spark

 

[Superduper]

If you think that the high pass capacitors are worn (which does happen occassionally), you can change them. But remember to use only non-polarized caps and do not vary the capacitance too much or else you could reduce the protection to the tweeters. In general, you will find that the high pass caps on the speakers range from 2.2 up to 10uf. Never go higher -- it would pass too much low frequencies to the tweeter.

Instead of the capacitor, you can also install a diode too, but that generally is to reduce arcing when the contacts open.

 

[stevenrob]

the contact is clean but perhaps it is worn out.

The capacitor is 1 uf. I 'll try 4.8 uf.

The Wilco CRS 1047 is a very nice boombox but it is bottom of the range inside.

 

[Superduper]

Wait, 1uf? Really? What kind of tweeter is that and how many ohms impedance?

It looks like for 1uf cap @ 4 ohm impedance, the frequency is almost 40khz = useless.

If same 1uf cap @ 8 ohm impedance, frequency still almost 20khz. Only good for supertweeter. Many people can not hear above 20khz.

At 4.8uf, pass through frequencies will be 4.1khz/8.2khz at 8ohms/4ohms. Make sure the tweeters can handle it.

 

[stevenrob]

Thanks man. The speakers are in 4 ohms and it is really 1 uf capacitor. So, what is the good value for the capacitor ?

 

[Superduper]

4.8 is probably ok, did you try it yet? I think you'll mostly find 3.3uf in this application though.

 

[stevenrob]

Thanks ! I try with 4.8 uf. The sound islittle better on tape deck and nice on radio. I think the tape deck is cheap. Since I have my TPR 950, I'm very exigent