My cousin bought an Onkyo TX-4500 MKII and I restored it for him. I replaced all the electrolytics, filter capacitors, relay, cleaned all the controls and remounted outputs. I was really impressed with the sound of this unit so I decided to pick one up and do the same work for my unit. The unit I acquired was cosmetically near perfect but had some anomalies. The dial string was installed incorrectly so that when you turned the knob left the pointer moved right and the volume potentiometer was a regular one as opposed to my cousin's which was indexed. I thought that it must have been worked on at some point but all indicators when I went to open pointed to it not being ever opened. Was it strung improperly at the factory? Maybe the assembler had too much sake that day? Did Onkyo source two different types of potentiometers for the same model? Who knows? It turned out the loop around the tuning knob was backwards and after much time I was able to reroute the string and get it working as it should.
Because I was replaying the same script that I used for my cousin's unit, I didn't extensively test the unit out before getting into the bulk of the work. I hooked it up to the dim bulb, checked DC and then listened to the FM tuner through the headphones. It sounded okay, both channels came in clearly in stereo and I went ahead and did the recap, etc. After I finished I set it up properly with all sources connected and tested it out. I found that the output level and sound quality varied depending on the source being used. The tuner had a relatively weak output (I could get to 11 o'clock and still felt like it was lacking, I could barely hear it sub 9 o'clock). The phono input was a bit better but still lacked the fullness it should have. It sounds kind of tinny and so does the tuner for that matter. With the line in, however, it's a completely different story. It sounds super powerful and crystal clear (as it should). I can get to nice rock out output level at 9 o'clock.
I've been spending the better part of a month trying to figure out what would cause an issue like this and I've doe more work and testing to figure it out but I don't want to make this too long. Has anyone had an issue like this before? It seems to be a tough one because technically it is working; both channels are clear and distortion free. But I know something is off because I did a direct comparison with my cousin's unit and my findings checked out. His sounds awesome through the tuner, phono as well as the line in with no major discrepancies in output level or sound quality Appreciate any help with this.
Because I was replaying the same script that I used for my cousin's unit, I didn't extensively test the unit out before getting into the bulk of the work. I hooked it up to the dim bulb, checked DC and then listened to the FM tuner through the headphones. It sounded okay, both channels came in clearly in stereo and I went ahead and did the recap, etc. After I finished I set it up properly with all sources connected and tested it out. I found that the output level and sound quality varied depending on the source being used. The tuner had a relatively weak output (I could get to 11 o'clock and still felt like it was lacking, I could barely hear it sub 9 o'clock). The phono input was a bit better but still lacked the fullness it should have. It sounds kind of tinny and so does the tuner for that matter. With the line in, however, it's a completely different story. It sounds super powerful and crystal clear (as it should). I can get to nice rock out output level at 9 o'clock.
I've been spending the better part of a month trying to figure out what would cause an issue like this and I've doe more work and testing to figure it out but I don't want to make this too long. Has anyone had an issue like this before? It seems to be a tough one because technically it is working; both channels are clear and distortion free. But I know something is off because I did a direct comparison with my cousin's unit and my findings checked out. His sounds awesome through the tuner, phono as well as the line in with no major discrepancies in output level or sound quality Appreciate any help with this.
