I bought the service manual for this thing from eBay at a good price and just for the heck of it I thought to spend a few hours goofing around with it. I pulled four LM741s and installed sockets with TL071s. I pulled two 2SA733s and two 2SC945s and installed matched BC550s and BC560s, they were all 580 hfe measured on a little AtMega tester job. I banged up some resistors but they measure fine. I'll fire it up tomorrow and if it works I will try to calibrate the unit. If the circuit rejects the jfet TL0s I will revert to the 741s and try to calibrate. I don't know why I had to do this. It didn't take long and the parts were here. Probably a waste of time but just having a bit of fun. I'll check it out tomorrow.
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So far this little experiment has not worked out. I have to sit down and make friends with the calibration ritual. I hope to get this thing back on track in a week or so.
I have put some time into re-writing the service manual/user guide(some may have noticed already via the pics). The original was a joke by today's standards or even the standards when the unit was fabricated. Ha. Anyway, I'm working on a new version of the print manual too. I will most certainly share it here...
I have put some time into re-writing the service manual/user guide(some may have noticed already via the pics). The original was a joke by today's standards or even the standards when the unit was fabricated. Ha. Anyway, I'm working on a new version of the print manual too. I will most certainly share it here...