Hi,
Hello,
I trying repair Genelec s30's.
- its a three way active speaker
- bass, mid, treble has it own amp
- changed many parts and got it running.
Problem is treble amp offset reads -32 VOLTS when COLD!!
- treble amps bias is fine
- When amp heats up dc offset drops to +- 50mv, this is withing Genelec specs
- Dc offset bounces a lot when hot, from 50mv to 10mv then to 70mv and back to 50mv
Bias is stable when hot
- Genelec specifies that amp should be measured hot, but this is way too much when cold
- when this amp is working normally, offset is max 200mv when cold. (I have many S30 amp boards that work well)
- offset trimmer pot is tested and ok
- the whole treble amp board was resoldered just in case, looking for bad connection, no changes
- When amp is hot and its turned off for a couple of seconds, DC offset is immediately -5.00 Volts from -50mv. And starts super slowly rising back to 50mv
Where is the fault?
Hello,
I trying repair Genelec s30's.
- its a three way active speaker
- bass, mid, treble has it own amp
- changed many parts and got it running.
Problem is treble amp offset reads -32 VOLTS when COLD!!
- treble amps bias is fine
- When amp heats up dc offset drops to +- 50mv, this is withing Genelec specs
- Dc offset bounces a lot when hot, from 50mv to 10mv then to 70mv and back to 50mv
Bias is stable when hot
- Genelec specifies that amp should be measured hot, but this is way too much when cold
- when this amp is working normally, offset is max 200mv when cold. (I have many S30 amp boards that work well)
- offset trimmer pot is tested and ok
- the whole treble amp board was resoldered just in case, looking for bad connection, no changes
- When amp is hot and its turned off for a couple of seconds, DC offset is immediately -5.00 Volts from -50mv. And starts super slowly rising back to 50mv
Where is the fault?
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Hello Sir, i have bought a pair of Genelec S30 speakers with some problems. I have found a service manual online. But there is no text and explanation where to measure like yours. Is it possible to send me your service manual, or a link where i can download it myself? Thank you in advance. Greetings Martijn