I purchased the Krell FPB200 a few years ago with the intention of repairing it. I'm now at that stage (I know late). Anyway, the left channel is almost exactly 1/2 the output of the right channel. It sounds good but way low. I measured the power supply and it supplying the right voltage. So far I haven't been able to spot the problem and wanted to see if anyone else has had a similar problem and where was it coming from. Any tips on troubleshooting this would be helpful since Krell is down for now. I've attached the schematics for review.
Thanks,
John
Thanks,
John
Half the output ? So you are losing amplification .. it just plays not as loud as the other channel ?
This is a bridged Amplifier, if you miss exact 6dB ... one side may run idle. Does a scope show output on both connectors (+ & - Output) against ground ?
Check a couple of capacitors in the servo amps. When the capacitors get bad the servo amp start creating feedback in the audible range and you lose amplification.
Check or replace C11, C12, C13 and C14 (sitting next to U3 and U31). Measure their ESR ...
After replacement also Check DC-Levels at Pin 6 of U3 and U31. If it is more than 1V you may have additional problems.
Hope this helps
Peter
This is a bridged Amplifier, if you miss exact 6dB ... one side may run idle. Does a scope show output on both connectors (+ & - Output) against ground ?
Check a couple of capacitors in the servo amps. When the capacitors get bad the servo amp start creating feedback in the audible range and you lose amplification.
Check or replace C11, C12, C13 and C14 (sitting next to U3 and U31). Measure their ESR ...
After replacement also Check DC-Levels at Pin 6 of U3 and U31. If it is more than 1V you may have additional problems.
Hope this helps
Peter