# Capacitor identification

#### Satman17

Joined Feb 19, 2021
12
Can anyone identify this capacitor please it says 4.7K but it’s a capacitor I’m confused

thank you

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#### twohats

Joined Oct 28, 2015
447
4.7k = 4.700nF Hence the 'k', or 4.7uF with a working voltage of 100

Good luck..

#### Satman17

Joined Feb 19, 2021
12
Seems that a higher voltage cap seems to last longer by whatever read

#### Audioguru again

Joined Oct 21, 2019
6,693
4.7k = 4.700nF Hence the 'k', or 4.7uF with a working voltage of 100

Good luck..
Absolutely not!
It has a capital K that means a tolerance of 10%. Capital J is 5% and M is 20%.
It is huge and is used in a speaker crossover so it is 4.7uF.
I think an oriental one would be marked 475.

EDIT: I see that you are in the UK and instead of writing 47000nF you wrote 4.700nF which is actually 4.7nF.

#### Audioguru again

Joined Oct 21, 2019
6,693
Seems that a higher voltage cap seems to last longer by whatever read
Nope. A film capacitor will last forever if you never apply a voltage higher than the voltage rating.
A rating of 100V would be a peak voltage of 100V into an 8 ohm speaker which is 625 watts. An amplifier with a 625W output would use an active crossover circuit not needing a high voltage film capacitor.

#### Satman17

Joined Feb 19, 2021
12
Well it looks like the speaker is knackered As no resistance 6ohms

#### Audioguru again

Joined Oct 21, 2019
6,693
Tweeters are delicate. If an amplifier is played too loud which produces severe clipping distortion then all the high pitched distortion harmonics burns out a tweeter. The crowd cheering during a ball game can also burn out a tweeter if it is played loudly.

#### Satman17

Joined Feb 19, 2021
12
Well I’ve just connected the wires which were originally on the tweeter to one of the side speakers, sounds pretty good now.
I’m obviously looking for a replacement middle tweeter (pictured)

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#### ApacheKid

Joined Jan 12, 2015
1,611
Well I’ve just connected the wires which were originally on the tweeter to one of the side speakers, sounds pretty good now.
I’m obviously looking for a replacement middle tweeter (pictured)
In case you don't know do not apply DC or low frequencies to that tweeter.

Years ago I did that, I wanted to "test" the tweeter and knew if put a battery across it with some wire, Id hear it click and crack if it was working, I'd done that hundreds of times with cheap little speakers in transistor radios or old speaker taken out of TVs. I did that, it clicked and died, no smoke, no indication only silence after I'd made that initial contact with battery.

This was in the early 80s, no idea if they're different or more rugged now. (the tech notes even mentioned not applying anything without a filter/crossover in place - did I listen? No).

#### KeepItSimpleStupid

Joined Mar 4, 2014
5,088
Replace the tweeter in pairs. Sound will be yucky of you don't.

The dome tweeters I have used got scratchy.

Never applied a 1.5V battery to a tweeter, but have with larger speakers to determine polarity.

#### wayneh

Joined Sep 9, 2010
17,498
Never applied a 1.5V battery to a tweeter, but have with larger speakers to determine polarity.
1.5V and 6Ω = 0.25A, or about 0.4W. It can take it.