I checked into my KSA80B amp for some minor repair on the protection board.
Needed to exchange the ROE 470uF in the power supply. While case was open I adjusted offset on one channel and was able to adjust from 50mV to around 6mV.
My emitter resistor voltage was measured to 200-220mV (4 places). This is a bit low as manual states 325mV for correct bias.
Now to my concern, I’m not able to find a trim pot for this! Even with glasses on and flashlight I couldn’t find a second pot on the main board.
Does anyone have a correct lay-out to share or can advise?
Thanks
Needed to exchange the ROE 470uF in the power supply. While case was open I adjusted offset on one channel and was able to adjust from 50mV to around 6mV.
My emitter resistor voltage was measured to 200-220mV (4 places). This is a bit low as manual states 325mV for correct bias.
Now to my concern, I’m not able to find a trim pot for this! Even with glasses on and flashlight I couldn’t find a second pot on the main board.
Does anyone have a correct lay-out to share or can advise?
Thanks
Yes, I know it does. But I got KSA80B.
And I can’t find the pot on the board.
Is bias fixed or is the pot “hidden” somewhere?
And I can’t find the pot on the board.
Is bias fixed or is the pot “hidden” somewhere?
I am looking at a KSA80 I have only found trimpots on the rear panel labeled L and R I moved them a little, but saw no appreciable change in the bias or offset. Has anyone out there been able to adjust these. R sink is 53C (280mv) and L sink is 50C (210mv)
Rear panel (board) is for protection and soft-start.
I think those pots are current limit for protection circuit.
I think those pots are current limit for protection circuit.
If you read this thread then you may find that you are "member of the club" 🙂
https://www.diyaudio.com/community/threads/krell-ksa-200b-bias.291507/
LOL, Thanks for that. Luckily, all I need to do is replace the caps to freshen up the power supply circuits.