Fischer Audio Anthaeus Aktiv Turbo Repair
22/09/2015
Once I was done with taking out all drivers, I took the electronic modules out, too. Note that the way they are marked (R and L) doesn't match the way I had the speakers in the room. I had them with the tweeters on the inner sides, but maybe the tweeters should be on the outer sides of the speakers? No idea. All photos I found on the web were identical to my setup. Honestly, I don't know who wrote "R" and "L" on the modules. I wrote "132" and "137" to match the serial numbers. Perhaps someone swapped the modules in the enclosures. The truth is that the modules were at SAC for a repair/overhaul in 2007 and had some capacitors replaced. Maybe the owner swapped the modules then when putting them back.
Then I started finding the discrepancies in the electronics. I think this is the soft start board. Note the different resistors as well as the swapped cables leading to/from the rotary switches section. According to the soft-start scheme, the module SN 132 should be correct, at least as far as the resistors go. I am going to have all that checked professionally against the schematics that I have from SAC.
Another discrepancy, this time in the power amps. Note one capacitor's polarity is inverted in the SN 132 module. I am not sure if this matters. All capacitors were checked and bad ones exchanged during a check at SAC in 2007. If this is the result or if it passed the check and it makes no difference, I don't know yet.
One of the filtration capacitors have leaked out in the SN 137 module since that check.
Again, some inverted polarity of capacitors between the two channels. Not sure if this has any functional implications but it's there.
Complex view of both modules with discrepancies marked. I have yet to open the rotary switches box.
Then I started finding the discrepancies in the electronics. I think this is the soft start board. Note the different resistors as well as the swapped cables leading to/from the rotary switches section. According to the soft-start scheme, the module SN 132 should be correct, at least as far as the resistors go. I am going to have all that checked professionally against the schematics that I have from SAC.
Another discrepancy, this time in the power amps. Note one capacitor's polarity is inverted in the SN 132 module. I am not sure if this matters. All capacitors were checked and bad ones exchanged during a check at SAC in 2007. If this is the result or if it passed the check and it makes no difference, I don't know yet.
One of the filtration capacitors have leaked out in the SN 137 module since that check.
Again, some inverted polarity of capacitors between the two channels. Not sure if this has any functional implications but it's there.
Complex view of both modules with discrepancies marked. I have yet to open the rotary switches box.
29/09/2015
I opened the rotary switches box. They look the same. The green-yellow and grey cables at the left hand side of the photo are some custom modifications that disabled the Level switch on the back of the speakers. Someone had really been tampering with this pair. I had them both removed.
These are the two cables that are also switched at the other board.
These are the two cables that are also switched at the other board.