Hi, ive been having this hum thats been comming out of my right magnapan speaker. Well first thing is that my whole system is on the right side of the room and the speaker is right next to the equipment but its been like this for years and I never had a hum before. This seems to happen when using the turntable but only with certain albums that have been recorded at a low levels causing me to turn up the pre amp past 12o clock. Recently I put my speakers on mye stands with magic sliders and I dont know if that may have caused an issue or mabey its a bad vaccume tube? I tried moving the speaker around the room didnt seem to do much but the hum seems at its worst at the best listening spot (go figure). Mabey its my cartridge? I dont know but right now my turntable is about 30 inches away from the speaker. The hum is not horrible but when the music gets quiet it can be annoying. I did swap the speakers and with the tweeters on the outside the hum seems to be worse not better.
Pull the speaker cables out of the binding posts on the speakers and change places. The speaker cable that used to go to the right speaker now goes to the left. And the same thing for the other one. Don't touch the other end of the cables that connect to the amp. Play some music and see if the problem moves to the other speaker, or stays where it is. If the hum still comes from the same speaker, that's where your problem is. Otherwise, its something else in the system. Do that first and then post back. The overall idea is to isolate each piece in the system, one at a time, so you can confirm if it is or isn't working properly. You just keep eliminating components until you come across the bad one.
Try turning on the turntable, turn up the volume some and move the tonearm across the platter slowly. If you don't hear a hum at first but do when the tonearm is moved across the platter, relocate your ground wire. Best of luck.
Hi thanks guys for your input! So far I eliminated about 98% of the hum! What I did first is I put the speakers back to tweeters on the inside. Then I Moved the amp and the turntable as far away from the preamp as I could. Then I played the same record that was causing the issue and it was much better!. I think I narrowed it down to the preamp because when the record is over I can still hear a slight hum so I tapped my finger on my arc sp8 preamp and I can hear a thumping hum noise when I tap then it goes away. Then when I take the needle off the record its back to dead silence. So mabey its a bad tube or just the transformers of the amps need some space or the turntable needs some space, but the fact that I got a positive result so far is encouraging.
Well I think I found the culprit it was the turnable/interconnects. What happened was I found a piece of granite that I used to use as a cuttingboad from my kitchen lol. I thought this would be a good idea to stick under the preamp and try to isolate it from the other components. Well when I put it under the preamp nothing changed. So I decided to put the turntable on it and when I played a record all of the sudded only sound was comming out of the left speaker. I looked at the interconnects and they were in there and so was the ground wire so I moved the wire around and all of the sudden the sound came back on! And the hum was completely gone! This is weird because the interconnects are brand new and they werent loose. The ground wire was a little loose but still in there tight so I think its strange but its definitely related to the turntable.
"01-24-15: Barruch86 Hi thanks guys for your input! So far I eliminated about 98% of the hum! What I did first is I put the speakers back to tweeters on the inside. Then I Moved the amp and the turntable as far away from the preamp as I could. Then I played the same record that was causing the issue and it was much better!"
Something isn't right about how you fixed your problem. I doubt that moving the speakers was the solution. Are you absolutely sure all of you cables are in good shape, no loose connectors or any other type of damage? It could be that when you were moving stuff around, you moved the cables in such a way as to make a better connection, and just didn't realize it. I could be wrong, of course, but still wouldn't be a bad ides to check all the cables and connections again.
Sounds like you had some schmutz on your connection. One of the symptoms will be that you will pick up more noise (including hum), and another symptom is that it will be sensitive to vibration (tapping on it makes it cut in and out).
The schmutz causes a high impedance connection, which still can couple in the signal, but the high impedance connection becomes more susceptible to pickup of stray magnetic fields. It's like you created an antenna.
The high impedance connection of the dirt also creates a variable resistor, which changes value under the pressure of vibration. The vibration causes changes in connection impedance and often causes a crackling noise as it changes value. Vibration of the surface the preamp is sitting on becomes modulated into the signal through this variable connection. It is one form of what is commonly called "microphonic noise".
Mental ahah yea sometimes I make no sense either lol. Yea its or it was a small hum that came out of the right speaker only when the volume was turned up to a specific level. That level being very loud past 12 o clock. The hum would get stronger the higher up past 12 o clock. I very rarley go up that high but some records are recorded pretty low or I just like the music so much i have the urge to crank it up lol. Anyway it is possible that the interconnect wasnt completely in there and it got pushed in place when I was moving things around. Tom32, wow thats very informative and great idea, ive never cleaned the connectors, im shure my old sp8 is pretty dirty. Again thanks, you guys are the best!
Sometimes cables fresh from the factory are the worst for schmutz. There can be like this oil stuff on the connector, that is a residue from the manufacturing process.
And what is worst is when you have the oil get from the jack into the socket, because it is harder to clean then. The way to clean that out is to first clean the jack with alcohol, then plug the jack in, jack it in and out, and then clean the jack again. Repeat until you get a solid connection every time you plug in. Your using the clean jack to wipe out the socket.
A totally different topic... if you crank an amp up and the hum gets relatively louder than the music, it can be a sign of having an electrolytic power cap in the power supply going bad. What happens is that the cap is weak, and at high current draw of the amp, the weakness shows up as being significant, but at low volume the cap is able to keep up with the current demand. What was a hefty 4700 uF cap has degraded to a 500 uF cap, and it is not able to smooth out the 60 Hz ripple of the AC power supply when load current demand gets high. There isn't much you can do about a problem like that, the cap will progressively degrade over months or years, and eventually fail altogether. The cap has to be replaced.
If the hum is coming in through the signal path, the relative volume of hum to music volume will remain the same as you crank up the amp.
Oh wow i never thought that it could possibly be a cap issue, i dont think it is, but it might be . My power amp is an audio research vs110 that is about 10 years old now and pre amp well is probably 28 years old lol. I bought them both used, but the sp8 does have nichicon elecrolytics and im not shure if they are original or not. I think they used spragues back then but I could be wrong. The question I have is if its an electrolytic cap getting weak, then wouldn't both of the speakers hum instead of one? The hum did dissapear for now, but if it comes back then yea your right it might be a cap!
Its def the right interconnect cable on the turntable because again today the right side was out again with just a hum. I touched the right interconnect cable connected to the turntable and the sound came back on with no hum! I havent cleaned the system yet so ill clean the schmutz on the turntables connectors first and tighten the ground screw as that could have been a bit tighter. I hope this was the issue and not a cap because that sounds like id have to send them to a repair shop and I dont know how much that would cost lol.
I think your problem is schmutz and not a cap. I mentioned the common cap problem because the symptoms are similar. I wanted other people who are reading this to know how to tell power supply hum from pickup hum.
When the noise is coming from pickup in the signal path, the signal to noise ration remains the same, because you are faithfully amplifying both of them. When the hum is a droopy cap in the amp power supply, the signal to noise ration will be worse when you crank it up. It might even start "motor boating". Also, a power supply cap that is on it's way out gives off an acidic smell, like lemons.