jcmusic Posted August 12, 2006 Share Posted August 12, 2006 I have a hum that was very slight before I moved my TT, now it is 3 times as loud. In trying to track it down I noticed that the hum is present even when the TT is off, not powered. Does this mean pretty much for sure the hum is in the phono pre amp? jay Quote Link to comment Share on other sites More sharing options...
Gilbert Posted August 12, 2006 Share Posted August 12, 2006 Can you try to isolate the source, component by component. Quote Link to comment Share on other sites More sharing options...
jackpod Posted August 12, 2006 Share Posted August 12, 2006 try flipping the power cord plug over 180 degrees. Jack Quote Link to comment Share on other sites More sharing options...
jackpod Posted August 13, 2006 Share Posted August 13, 2006 also, if that gets you back to where you were (slight hum) then try flipping the power plug on your receiver/preamp over 180. If any of your equipment has a 3 prong plug, get one of those 2 prong to 3 prong adapters and don't fasten the ground. Hum is often caused by gound loops (more than one connection to ground) Jack Quote Link to comment Share on other sites More sharing options...
SilverSport Posted August 13, 2006 Share Posted August 13, 2006 If you "lift" (am I using that term right???) all the grounds by using the cheater plugs (eliminating your ground) but plug all this into a "spike protector" which has a three pronged grounded plug and plug this into a grounded wall socket...have you re established the ground for everything at the wall outlet? Bill Quote Link to comment Share on other sites More sharing options...
hwatkins Posted August 13, 2006 Share Posted August 13, 2006 Folks have already given the basic ground loop advice (which is good). If none of this works I would also look at my direct to source connections at amp, pre and TT. I have seen, more than once, the loop introduced in an often used RCA connection (bad/cold solder, etc.). It is most often with TTconnections as well. Quote Link to comment Share on other sites More sharing options...
SilverSport Posted August 13, 2006 Share Posted August 13, 2006 I would agree on the TT connections...NOTORIOUS for causing this. Bill Quote Link to comment Share on other sites More sharing options...
jackpod Posted August 13, 2006 Share Posted August 13, 2006 considering that once you get to the breaker box, your neutral and ground become one, yes, from the perspective of the load side of the spike protector, no. Remember 3 prong outlets are for safety, offering a dedicated path to ground in case of malfuction. Polarized plugs (one blade wider) is to keep the "hot" wire from being connected to the chassis. From an electrical standpoint the only difference between the neutral wire and the ground wire is the color. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted August 13, 2006 Author Share Posted August 13, 2006 OK guys the hum is only present when i turn on the phono pre amp. I did not have this hum until i put the TT into the system. I have tried fliping the plugs, changing the power cords etc. My question was is possible that the problem is in the phono pre amp? I get this hum with the TT off, no power to it. Jay Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 13, 2006 Share Posted August 13, 2006 1)Does the Phono Preamp have a 3 pronge power cord? If so try a 3 to 2 cheater plug on it. 2) Is the Phono preamp grounded to the main preamplifier or integrated amp? It should have a ground wire run between the two devices and possibly another between the turn table and the phono preamp.... or to make things more complicated any combination of grounded and not grounded. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted August 13, 2006 Author Share Posted August 13, 2006 Craig the phono pre has 3 prongs, i have already tried going too 2 prongs no luck. I will try grounding the phono pre too the main pre amp. jay Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 13, 2006 Share Posted August 13, 2006 Jay, Once you ground the phono preamp to the amp also try with and without the cheater plug on the phono preamps power cord. I bet you solve the problem with some combination of grounded/not grounded. Craig Quote Link to comment Share on other sites More sharing options...
jcmusic Posted August 13, 2006 Author Share Posted August 13, 2006 Craig you say to ground the phono pre amp to the amp? or the main pre amp? jay Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 13, 2006 Share Posted August 13, 2006 Lets make this easier call me 810-287-6135 if I don't answer leave your number I'll call back shortly. Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted August 13, 2006 Moderators Share Posted August 13, 2006 Lets make this easier call me 810-287-6135 if I don't answer leave your number I'll call back shortly. Well, You know that problem is solved, 'cause Craig was in the house! Travis Quote Link to comment Share on other sites More sharing options...
jcmusic Posted August 13, 2006 Author Share Posted August 13, 2006 Well guys i have it back to where it was in the begining, at lest i can listen to it. I still have a problem, it will take some time. Thanks to all the guys who helped out. jay Quote Link to comment Share on other sites More sharing options...
DrWho Posted August 13, 2006 Share Posted August 13, 2006 What'd you end up doing to fix the problem? I just wanted to throw in a quick comment about the cheater plugs; their use decreases the safety of your equipment. If a cheater plug works, then you know you have a problem with your power source that should be corrected. Though the sonic problem is gone, the electrical problem is still there. I use cheater plugs all the time so I'm not condoning their use, but twice now I've been electrocuted as a result. Just something to keep in mind. Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted August 13, 2006 Moderators Share Posted August 13, 2006 What'd you end up doing to fix the problem? I just wanted to throw in a quick comment about the cheater plugs; their use decreases the safety of your equipment. If a cheater plug works, then you know you have a problem with your power source that should be corrected. Though the sonic problem is gone, the electrical problem is still there. I use cheater plugs all the time so I'm not condoning their use, but twice now I've been electrocuted as a result. Just something to keep in mind. Dang Dr.!!! Electrocuted or just shocked? How on earth did you manage that? I get a good buzz everytime I touch the ic on the back of my MX110, 1963 preamp with non-polorized two prong plug, and and IC on the back of one of the amps. Not anything major, but it makes me jump like crazy every time it happens. Travis Quote Link to comment Share on other sites More sharing options...
DrWho Posted August 13, 2006 Share Posted August 13, 2006 No, it was definetly electrocution - my arm was numb for a week both times. I've been electrocuted dozens of times though - you kinda get used to it after a while [] The worst time was when I was tucked in a very tight spot behind some equipment racks trying to unscrew something audio related. I slipped and got the screwdriver wedged in a 220V socket and my arm got stuck in such a way that I couldn't pull out. It seemed like forever for the circuit breaker to flip - my arm was hot (not burned thank goodness) and I was all staticky. I was around 12 at the time so you can imagine the horror for the old guys that wanted to take advantage of my small size [H] Ignoring the scary part, it was by far the coolest sensation ever - don't think I'll try it again though... [] The only thing that hurt was my head that shot up and smashed into a metal bar. They say the reaction to the shock is often more dangerous than the actual shock itself. Quote Link to comment Share on other sites More sharing options...
rcarlton Posted August 13, 2006 Share Posted August 13, 2006 DrWho...you couldn't have been electrocuted! I saw you in Hope. The term electrocution can mean either: accidental death or suicide by electric shock deliberate execution by electric shock, usually involving an electric chair Quote Link to comment Share on other sites More sharing options...
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