As speakers pop when i power on my amp (Creek 4330) i thought of connecting a suppresion capacitor (X2 0.47nF 275V) on the switch.
I'm a little confused where to connect it, can you have a look at the photo and guide me through?
The thick cables (pins 1&2) come from the mains socket and the thinner are connected to the transformer's prime.
Cheers
I'm a little confused where to connect it, can you have a look at the photo and guide me through?
The thick cables (pins 1&2) come from the mains socket and the thinner are connected to the transformer's prime.
Cheers
Attachments
Ordinarily supression caps are put across the NO (normally open) pole of the switch to eliminate turn off pop.
Only you can determine with an ohmmeter (power unplugged) which pair of these terminals are the normally open contact. 0 ohms on, 1999 ohms open. One side goes to the hot in, another to the transformer primary.
In the US one capacitor is usually sufficient. I don't know if eastern hemisphere designs with both mains powered suppress both poles of the switch.
Internal design features of the amp usually supress turn on pop.
In the UK with 220 vac mains, a 275 v rated x2 cap is a little marginal IMHO.
Only you can determine with an ohmmeter (power unplugged) which pair of these terminals are the normally open contact. 0 ohms on, 1999 ohms open. One side goes to the hot in, another to the transformer primary.
In the US one capacitor is usually sufficient. I don't know if eastern hemisphere designs with both mains powered suppress both poles of the switch.
Internal design features of the amp usually supress turn on pop.
In the UK with 220 vac mains, a 275 v rated x2 cap is a little marginal IMHO.
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The best place for the cap is across the transformer primary, not the switch. This makes the cap last longer, and also means 'off' means off. It won't affect switch-on pops, only switch-off (unless you have serious switch-bounce).
275V X2 is fine for 240V mains, as the X2 spec knows about overvoltage.
275V X2 is fine for 240V mains, as the X2 spec knows about overvoltage.
Better to snub the high voltage back emf at the Source, i.e. across the inductive load.
As the AC mains has almost zero impedance the cap will suppress sparks just as well whether it is across the switch or across the transformer primary. However, only the latter ensures long life for the cap and 'off' really means off. This assumes that the amp will be 'off' (but connected to the mains supply) more than it will be 'on'.
It doesn't seem to be generally known that X-rated caps gradually lose value. This is an apparently unavoidable consequence of their fail-safe properties. Every big mains spike removes a little bit of capacitor plating, so reducing the value. Typically, if connected permanently across the mains something like 50-70% of capacitance can disappear in 5-6 years. This is why mains-powered doorbells, oven controllers, central heating thermostats etc. fail at about this time - they use an X cap as a voltage dropper.
It doesn't seem to be generally known that X-rated caps gradually lose value. This is an apparently unavoidable consequence of their fail-safe properties. Every big mains spike removes a little bit of capacitor plating, so reducing the value. Typically, if connected permanently across the mains something like 50-70% of capacitance can disappear in 5-6 years. This is why mains-powered doorbells, oven controllers, central heating thermostats etc. fail at about this time - they use an X cap as a voltage dropper.
This is what i read and i asked you to step in:
http://www.diyaudio.com/forums/solid-state/5678-speaker-thump-amp-question.html#post56162
http://www.diyaudio.com/forums/solid-state/5678-speaker-thump-amp-question.html#post56162
That is a different problem, so different solution. A suppression cap can prevent switch on in one item of equipment from creating clicks in another item.
The switch for an amplifier cannot create switch-on clicks in that amplifier, because at the point of switching on the amplifier has no power supply voltageand so cannot produce any output. A few 10's or 100's of ms later the amplifier is working, but the switch has already been moved so no noise to generate. The only exception would be an amp with a very fast PSU and a very bouncy switch.
The switch for an amplifier cannot create switch-on clicks in that amplifier, because at the point of switching on the amplifier has no power supply voltageand so cannot produce any output. A few 10's or 100's of ms later the amplifier is working, but the switch has already been moved so no noise to generate. The only exception would be an amp with a very fast PSU and a very bouncy switch.
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