Sony SA WMS5

[revoldius]

I've bought this subwoofer really cheap, works great but have a question. It has an auto power off, which is usefull because that way it uses a little less power. Now I would like to modify the time it stays of. So I want to know which component is the one that regulates the time.

Schematic:

[budm]

Re: Sony SA WMS5

"Now I would like to modify the time it stays of" Can you clarify that? You wan it to stay OFF and not turned on automatically when audio signal is present?
The circuit right now will make the unit stay on as long as it detects the audio signal, when the signal is not detected, then after fixed period of time is timed out then it will go into standby mode.
The signal detection and the ON time is done by IC602 NJM2072 and the timing cap C609 (1000uf 6.3V).

[revoldius]

Re: Sony SA WMS5

That opening post sounded a lot better in my head, now it just seems like garbage...
What I wanna do is change the time the unit stays on. Because some movies have quiet scenes and then suddenly a deep base scene. Problem is the sub isn't fast enough in switching on. So I needed to find out how to change the time.

Can I change the value of the capacitor to any value, or do I need to stay within a certain range?

[budm]

Re: Sony SA WMS5

OK, that makes more sense now.
Right now the stay-on time is done by that 1000uF CAP C609.
Typical sub woofer will stay on after the quiet period from 10~15 Minutes (my JBL does).
So it can be that C609 lost its value, or the jumper on the connector CN603 is missing.
The larger the value of C609 the longer will will stay on after quiet period.
Did you try measuring the time how long it stays on after the audio signal is removed? you can see the LED status light.