I have been working on this Kenwood a lot of this week. A friend sold it to me cheap, as it was stuck in protect mode... I kind of listened in on the amp section and heard that there was a lot of noise from bad transistors, in this case it was the 2sa733's as the differential pairs and others, which i can only assume was a bad batch back then, as generally they have a solid rep as reliable transistors... so I checked my supplies and I had enough KSA922 and KSC1815 to completely restock the amp driver board, and while I was at it, I recapped it and then recapped the power supplies... all of them... and replaced the rectifier, as it seemed like it was a little weak for the system... I noticed that some output transistors had been changed so I replaced the whole lot with the MJ replacement... (the number escapes me) and so now it has all new outputs... and it sounds pretty good... but TWO issues:
1. I can't set the bias... it's not affected by the pot, and the pot is good. I believe I changed he bias transistors.,, the receiver sounds good, clean, clear and powerful, I just can't get the bias to work.
2. The radio sounds distorted, JUST A LITTLE... like it has a subtle harmonic distortion, or compression... some channels aren't that bad, but loud ones sound loud or a little saturated... is there a way to control the gain in the stereo or clean it up? I included a few pics. I forgot to take them during the repair! lol
1. I can't set the bias... it's not affected by the pot, and the pot is good. I believe I changed he bias transistors.,, the receiver sounds good, clean, clear and powerful, I just can't get the bias to work.
2. The radio sounds distorted, JUST A LITTLE... like it has a subtle harmonic distortion, or compression... some channels aren't that bad, but loud ones sound loud or a little saturated... is there a way to control the gain in the stereo or clean it up? I included a few pics. I forgot to take them during the repair! lol
