Dc Offset Fisher Ca-880

montecarlossfan

Active Member
I measured dc offset on my fisher CA-880,from a cold start it was at 85mv...after 5 min warmup 71mv, 10 min 50mv, Is there any adjustments to these or is that all stk 0080 independent?
 
The differential transistor pair- feeding the signal to the STK packs will probably need to be replaced with a matched pair..
 
thanks..Is it possible this unit has been like this since the day it left the factory? Because this unit doesn't seem like it has seen much use at all..Not a scratch on it! heck the knobs don't even have a wear mark on them.
 
I was searching for info on the ca 880, and came across this. I also have one with
problems, and am unable to find a schematic, just wondering if you might have one.

Tnx, Bill wlgrant6@yahoo.com
 
I too am looking for service manual or schematic. I have an 880 and 800. I'll keep looking and check back here if anyone finds anything.
 
I may be able to give some tips. I am the second owner of the one I have and a friend of mine fried my left channel a few years back. It now has a complete new left channel including the new STK-0080.
 
Which transistors are the differential pair. I have a 800 and 880. Not many caps. Does anyone have a cap list? Also does anyone have info on lamps. I have the small ones with leads attached and blue ones in the meters. I have no idea of voltage.
A service manual would be great but maybe too much to ask.
 
fisher ca-880 distorted output

howdy, i have a ca-880 that had no output. I replaced both STK output mods and now have audio in both channels. The problem is that the right channel is distorted. I am looking for a print or any advice as to what might be causing the distorted output. I am trying to trace the signals with a scope but it is time consuming!
Any and all help is greatly appreciated.
Gary
 
Personally, I just hate those STK power modules 'cause they contain all of the tone and preamp circuitry, but my CA-880 was sold to me from a person who died of AIDS, so its the sentimental value of why I like mine and am keeping it. Still works great, but I have not encountered distortion with those paks, so maybe someone else with that type of experience may be of some help.

A power pak could still be defective even brand new, but I would look at those differential pair of transistors and check for out-of-spec resistors in that channel.
 
Back
Top Bottom