knockbill
Lunatic Member
Just picked up a Fisher 220 receiver at Hamfest today,,,
I started on AK with all the help I got here, recapping my Sansui 800, but soon after got hooked on tubes...
Never had a Fisher piece before, but this doesn't look too complicated, seems a lot of the transistors plug into sockets...
What kind of performance can be expected? Similar to the Sansui? Can the power amp, and preamp sections be separated (without major surgery!!), to use it as a pre w/ tube power amp?
I did a little testing/measuring today,,, there is static, probably leaking PS caps when its turned on, and also when it is shut down...
Used its tuner as an input, which really sounds good,,, main problem I see immediately is, the right channel is about 1/3-1/2 volume of the left... Using the balance control can make them even, but the L is much louder...
There are not too many V readings on the schematic, so I got PS readings, which were pretty close to schematic... Also, compared the 9 pins on each amp board, the R side board in the amp, reads slightly higher than the L...
Any thoughts how to find the problem, without just changing everything? This might be a good exercise in troubleshooting...
Once the caps charge up, the amp runs pretty quiet, other than the low R side output problem...
Schematic/manual is at.... http://www.hifiengine.com/manual_library/fisher/220-t.shtml
Regards,
John
I started on AK with all the help I got here, recapping my Sansui 800, but soon after got hooked on tubes...
Never had a Fisher piece before, but this doesn't look too complicated, seems a lot of the transistors plug into sockets...
What kind of performance can be expected? Similar to the Sansui? Can the power amp, and preamp sections be separated (without major surgery!!), to use it as a pre w/ tube power amp?
I did a little testing/measuring today,,, there is static, probably leaking PS caps when its turned on, and also when it is shut down...
Used its tuner as an input, which really sounds good,,, main problem I see immediately is, the right channel is about 1/3-1/2 volume of the left... Using the balance control can make them even, but the L is much louder...
There are not too many V readings on the schematic, so I got PS readings, which were pretty close to schematic... Also, compared the 9 pins on each amp board, the R side board in the amp, reads slightly higher than the L...
Any thoughts how to find the problem, without just changing everything? This might be a good exercise in troubleshooting...
Once the caps charge up, the amp runs pretty quiet, other than the low R side output problem...
Schematic/manual is at.... http://www.hifiengine.com/manual_library/fisher/220-t.shtml
Regards,
John