batteryman
New Member
Hello everyone
I am wondering if anyone would happen to be able to provide advice on this Adcom GFA-7500 amp channel I am working on?
I replaced 2 bridge rectifiers on one of my amp channels in an attempt to increase reliability as I have had others fail and now I am unable to properly bias it. I powered up using a dim bulb tester and the bias is now .34v verses what it was before .01 which is spec. The bias pot is a single turn unit turned all the way down. I just recapped this unit so I know its not due to stale caps. on the plus side the DC offset is great.
The original rectifiers were 8 amp rated units
http://html.alldatasheet.com/html-pdf/208646/PANJIT/SBU8G/214/1/SBU8G.html
The replacements are 10 amp rated
http://www.mouser.com/ds/2/80/KBU10005-G_KBU1010-G-3822.pdf
upgrading to a higher rated bridge should not have any affect on the amp output should it? After the bridge and filter caps are 8 amp fuses. I just was hoping to get something with a bit of overhead. I should note that while replacing the bridges I replaced the sand cast emitter resistors with Dale RS 1% units of the same value but I dont think that would have any thing to do with it.
Any help would be appreciated. Thanks in advance
here are some links to photos
https://photos.app.goo.gl/m6epxixXOKQ3gALy1
https://photos.app.goo.gl/yOoRBbwP2CI4rqrQ2
I am wondering if anyone would happen to be able to provide advice on this Adcom GFA-7500 amp channel I am working on?
I replaced 2 bridge rectifiers on one of my amp channels in an attempt to increase reliability as I have had others fail and now I am unable to properly bias it. I powered up using a dim bulb tester and the bias is now .34v verses what it was before .01 which is spec. The bias pot is a single turn unit turned all the way down. I just recapped this unit so I know its not due to stale caps. on the plus side the DC offset is great.
The original rectifiers were 8 amp rated units
http://html.alldatasheet.com/html-pdf/208646/PANJIT/SBU8G/214/1/SBU8G.html
The replacements are 10 amp rated
http://www.mouser.com/ds/2/80/KBU10005-G_KBU1010-G-3822.pdf
upgrading to a higher rated bridge should not have any affect on the amp output should it? After the bridge and filter caps are 8 amp fuses. I just was hoping to get something with a bit of overhead. I should note that while replacing the bridges I replaced the sand cast emitter resistors with Dale RS 1% units of the same value but I dont think that would have any thing to do with it.
Any help would be appreciated. Thanks in advance
here are some links to photos
https://photos.app.goo.gl/m6epxixXOKQ3gALy1
https://photos.app.goo.gl/yOoRBbwP2CI4rqrQ2
Last edited: