Breezio
Well-known member
Dear all,
After some extensive fixing of my hybrid amp AMC CVT3030 I am now facing the final challenge.
When I turn the knob Direct/Normal/Phones(Mute) I hear a rather loud cracking noise which eventually fades out after around 10mins of operation.
The knob is on the solid state preamp section (see schematic attached).
I have already replaced all the elcos on the signal path (C309/C311/C313 and C310/C312/C314) with Elna Silmic II.
In parallel to these caps there are 0.2uF Wima film caps.
In addition, I also replaced other elcos such as C305/C306, C325, C324 (all Elna Silmic).
I also measured the voltage over time at the switch (top of R323/R324) and here are the results. Values are in mV.
Measure Point R323 (L)
30sec: 230
1min: 110
3min: 70
5min: 55
Measure Point R324 (R)
30sec: -290
1min: -240
3min: -65
5min: -7
Any suggestions where else to look?
Thanks again
Fabrizio
After some extensive fixing of my hybrid amp AMC CVT3030 I am now facing the final challenge.
When I turn the knob Direct/Normal/Phones(Mute) I hear a rather loud cracking noise which eventually fades out after around 10mins of operation.
The knob is on the solid state preamp section (see schematic attached).
I have already replaced all the elcos on the signal path (C309/C311/C313 and C310/C312/C314) with Elna Silmic II.
In parallel to these caps there are 0.2uF Wima film caps.
In addition, I also replaced other elcos such as C305/C306, C325, C324 (all Elna Silmic).
I also measured the voltage over time at the switch (top of R323/R324) and here are the results. Values are in mV.
Measure Point R323 (L)
30sec: 230
1min: 110
3min: 70
5min: 55
Measure Point R324 (R)
30sec: -290
1min: -240
3min: -65
5min: -7
Any suggestions where else to look?
Thanks again
Fabrizio