hi
2 weeks ago i've bought an nice receiver heco 2000(german version of leak 2000).it worked fine but had a loud hum noise(around 120hz).so i've replaced the 2 power supply capacitors.2 decent samwha 10000uf 63v(the original 6800uf 40v).the hum noise there is still but now is very slight.more audible whit low impedence headphones.
the dc offset is:right: 55mV , left: 75 mV.a little high?
I've set the bias on other amps(whit very clear istructions on service manual), but the process for this heco/leak 2000 is not clear to me as my electronic skills are a bit basic. Can anyone spell out exactly where i should be placing my digital multimeter black-red probes?i've seen where is it the potentiometer vr1(on main amplifier pcb.2 vr1..i presume one for left channel and one for right channel). I've attached the instructions from the service manual.photo of part of service which explains how to adjust quiescent current and 2 photos of electrical diagram.
2 weeks ago i've bought an nice receiver heco 2000(german version of leak 2000).it worked fine but had a loud hum noise(around 120hz).so i've replaced the 2 power supply capacitors.2 decent samwha 10000uf 63v(the original 6800uf 40v).the hum noise there is still but now is very slight.more audible whit low impedence headphones.
the dc offset is:right: 55mV , left: 75 mV.a little high?
I've set the bias on other amps(whit very clear istructions on service manual), but the process for this heco/leak 2000 is not clear to me as my electronic skills are a bit basic. Can anyone spell out exactly where i should be placing my digital multimeter black-red probes?i've seen where is it the potentiometer vr1(on main amplifier pcb.2 vr1..i presume one for left channel and one for right channel). I've attached the instructions from the service manual.photo of part of service which explains how to adjust quiescent current and 2 photos of electrical diagram.
