adamp
New Member
Good afternoon AK gurus.....
I recently acquired a 2275. I love it and think I prefer it over my 2270. To my ears, anyway, it seems more detailed and a lot more than 5wpc more powerful, plus the FM tuner is far superior in terms of pulling in weak stations.
However, there is a pretty loud hum only on the AUX input. I tried a different cable from my CD player to the receiver, no change. Plugged the CD player (with the same cable) into tape 2 and there's no hum. It's only on aux which seems odd to me because a quick glance at the schematic doesn't indicate anything that is unique to the aux input and not the tape inputs.
I have to take it apart over the next couple days to replace the stereo indicator lamp, the dial vellum paper, and I usually adjust the power supply voltage, bias, and idle current to spec when I get a new receiver, so I'll poke around and see if I can find anything.
I'm thinking possible broken wire or flakey solder joint at the Aux input jacks? The hum sounds very much like when one of the cables to the input is only half plugged in and the grounding prongs around the outside of the cable aren't making good contact. Of course, while I'm in there, I'll look for any bulging/leaking caps as well.
Thanks for any input you may have....
Adam
I recently acquired a 2275. I love it and think I prefer it over my 2270. To my ears, anyway, it seems more detailed and a lot more than 5wpc more powerful, plus the FM tuner is far superior in terms of pulling in weak stations.
However, there is a pretty loud hum only on the AUX input. I tried a different cable from my CD player to the receiver, no change. Plugged the CD player (with the same cable) into tape 2 and there's no hum. It's only on aux which seems odd to me because a quick glance at the schematic doesn't indicate anything that is unique to the aux input and not the tape inputs.
I have to take it apart over the next couple days to replace the stereo indicator lamp, the dial vellum paper, and I usually adjust the power supply voltage, bias, and idle current to spec when I get a new receiver, so I'll poke around and see if I can find anything.
I'm thinking possible broken wire or flakey solder joint at the Aux input jacks? The hum sounds very much like when one of the cables to the input is only half plugged in and the grounding prongs around the outside of the cable aren't making good contact. Of course, while I'm in there, I'll look for any bulging/leaking caps as well.
Thanks for any input you may have....
Adam
