GMer56 Posted July 15, 2012 Report Share Posted July 15, 2012 I got a KLH Model 26 from a free box on the side of the road, and a pair of JVC SP-111 speakers for $1, and I love them.Besides needing a new needle (I have removed the current one), the Model 26 has a humming sound no matter what input I switch it to and or wheather I have my speakers or headphones plugged in.Is this normal? I have read that phonographs and such should naturally hum, but that should be caused by vacuum tubes, of which the Model 26 has none (or appears to have none).Any help would be appreciated. Link to comment Share on other sites More sharing options...
JKent Posted July 15, 2012 Report Share Posted July 15, 2012 Welcome!Maybe that's why it was free No--it should not hum.Hum is typically caused by one of 2 common problems: Bad ground or bad power supply caps. Either possibility is very likely. Those caps are beyond their expected lifespan.I don't have a schematic for the 26 but attached is one for the Eleven which is kinda sorta similar. It shows 3 caps on the PS board: 500uF/30v, 2000/30 and 1000/15. See what is in your amp and if you are up to it, try replacing the PS caps. You won't find 500uF but 470 is fine. I'd go up a notch on the voltage: 35 or 50v for the 30v and 25v for the 15.Also make sure the input RCA jacks are not corroded. The outer ring is the ground. Of course ground problems can be anywhere.....Keep us posted.Kent Link to comment Share on other sites More sharing options...
GMer56 Posted July 15, 2012 Author Report Share Posted July 15, 2012 Welcome!Maybe that's why it was free No--it should not hum.Hum is typically caused by one of 2 common problems: Bad ground or bad power supply caps. Either possibility is very likely. Those caps are beyond their expected lifespan.I don't have a schematic for the 26 but attached is one for the Eleven which is kinda sorta similar. It shows 3 caps on the PS board: 500uF/30v, 2000/30 and 1000/15. See what is in your amp and if you are up to it, try replacing the PS caps. You won't find 500uF but 470 is fine. I'd go up a notch on the voltage: 35 or 50v for the 30v and 25v for the 15.Also make sure the input RCA jacks are not corroded. The outer ring is the ground. Of course ground problems can be anywhere.....Keep us posted.KentThanks! There are some marks on the input (and output) jacks, but it hums even when there's nothing plugged in, so I think its the caps (I've also cleaned the inputs and outputs with rubbing alcohol).I've been tinkering with electronics since I was about eight 8 (that makes about 12 years of experience thus far), and I've desoldered quite a few caps in my day (and rebuilt a N64 controller port). I guess my only problem is finding some caps to use... to my junk box!If it's grounding problems I'd better break out my magnifying glass...Edit: Meh, I don't have money to invest in some caps right now, so unless I get really paranoid, I can deal with the slight hum. If I have my music up at adequate levels everything is fine Link to comment Share on other sites More sharing options...
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