Kef PSW2000 Sub schematic required

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Hi,
I will try to address most of the problems with this unit. As you know, the amp is located inside a plastic box. The temp has been measured to be over 80C. The standby on/off function works only on the speaker relay, the amp is always powered, hence the amp is always cooking and shortening the life of the components. Replace C59,60 with same rating. Relocate R 143,144 with the aid of flying leads. Increase wattage from 2W to 5W on R148,149 and R141,142 to lower resistor surface temp. Q18, 19 are to be replaced by BD139,140, and attached to the main heat sink. Drill holes and use screws. Remember mica. C42,43, replace with PP caps. Relay are to be replaced with Omron G5LE1-24, rated at 85C. Replace C54,55 with same type, only 105C. Same goes for C52.
Any questions? Just ask.

Regards
Roar
 
Instability problem on KEF PSW1000

I have been given a KEF PSW1000. It has a low level instability problem manifesting as a rough burbling noise/tone. This is audible when there is no input or on quiet passages in the music.

It gets worse after the amp is on for a period so may be heat related.

Shorting out the line inputs has no effect.


I would be grateful for any help.

Would the PSW2000 manual mentioned last month in this post be useful to me. I would appreciate a copy.

My e:mail is debataiduk@yahoo.co.uk
 
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