One of my Levinson ML-2 mono-amplifiers distorts heavily for a couple of minutes a day.
Conditions:
1. Amp is fully warmed up (hour minimum);
2. Audiocard has been swapped with the other Audiocard but distortion remains in the same channel;
3. Have already checked an squeezed together the 'Elco' (that's a brand) pins together that are used to connect the cards and mainboard.
4. Coldspraying the drivers in the two drivermodules did not change the behaviour (when it is in distortion mode it won't go to undistortion mode and vice-versa)
5. Coldspraying the eight outputtransistors or four regulatortransistors (all powertransistors are already been swiched for matched pairs of MJE15024/25 TO3's) does not yield any results either;
6. Biassettings (.53A over .56 Ohm emitterresistors), regulatorvoltage (28 Volts) and DC Offset (couple of millivolts) are okay even when in distorting mode.
I'm in limbo here.
Please any assistance would be welcome.
I have the servicemanual and schematics of the ML-2
Thanks in advance
Conditions:
1. Amp is fully warmed up (hour minimum);
2. Audiocard has been swapped with the other Audiocard but distortion remains in the same channel;
3. Have already checked an squeezed together the 'Elco' (that's a brand) pins together that are used to connect the cards and mainboard.
4. Coldspraying the drivers in the two drivermodules did not change the behaviour (when it is in distortion mode it won't go to undistortion mode and vice-versa)
5. Coldspraying the eight outputtransistors or four regulatortransistors (all powertransistors are already been swiched for matched pairs of MJE15024/25 TO3's) does not yield any results either;
6. Biassettings (.53A over .56 Ohm emitterresistors), regulatorvoltage (28 Volts) and DC Offset (couple of millivolts) are okay even when in distorting mode.
I'm in limbo here.
Please any assistance would be welcome.
I have the servicemanual and schematics of the ML-2
Thanks in advance
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Does it ever distort from cold? if not try reflowing all joints it could be a cold joint aggravated by thermal expansion.
Failing that, look at the electrolytic caps and any tants that might be on the board.
Failing that, look at the electrolytic caps and any tants that might be on the board.
Not once in the four days that I've operate them.
It's only for a couple of minutes then it's gone for the rest of the day.
You mean the blue large can ones in the PSU? (two big and four smaller ones)
It's incredible.
The original bindingposts are the offenders.
At the end I just started to fumble at all connections and yes outputconnectors worn out or whatever.
I gonna order the last series Fischer connectors so it won't happen ever again.
Thanks sq225917 you pointed me at the right track!
The original bindingposts are the offenders.
At the end I just started to fumble at all connections and yes outputconnectors worn out or whatever.
I gonna order the last series Fischer connectors so it won't happen ever again.
Thanks sq225917 you pointed me at the right track!
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