Why do i get a hum when i turn on 48v?
1457689
not sure exactly, but have you tried using a different cable and/or mic to see if the hum goes away? perhaps one of them is faulty.
1401261
I have not had that occur. I wish I could tell you more about what is causing that noise. It might have done so, but I had mine installed by a professional and I was not there for the testing. I have not had a power failure so it has not had to kick in either, so I haven't heard it in operation.
558413
Lee, I might offer that what you have is an electrical hum from an outside source like a computer or the current from your rig plugged into the wall. I experienced that before unplugging components and then listening. I still got to stick by this amp as it performs well for me not only busking a / stage work but studio work as well. Check for the proper wall adaptor or even call the people at Roland they actually answer the phone.well
1269493
The hum might be due to a ground loop. This problem often happens when you interconnect devices via RF/audio/video/etc. cable that are plugged into electrical circuits with different grounds. To troubleshoot this, try disconnecting FM antenna, input and/or output cables from your receiver. Assuming that you have any kind of cable connecting the TV to the receiver, also try removing the RF cable from the TV. Cable TV hookups are reputed to be common causes for ground loops. If the hum goes away with a particular cable removed, search online for a ground loop eliminator device for that type of connection. An inexpensive audio ground loop eliminator is available at RadioShack stores; higher-end audio ground loop eliminators are available online. Cable TV ground loop eliminators are available from online sources. For further information, search the Web for the words "ground loop". Hope this helps! Dave
872995
I have the same version but with a metal chassis and noticed this whine. I'm going to look into a replacement. It makes the noise about 20 seconds after plugging in the power.
282741
I not totally sure, but I know if there is humming you have some electrical interference. The cables are possibly too close to the conduit in the walls or some other issue. I've had no problems with my setup, but when I turn my microwave on the sub hums. Not a big deal for me since it's not used much. So it's worth a try, if not return it.
95292
Mine hums a little, but to hear it you have to be really close to the unit and have the sound volume low. Basically, it is transformer hum and because the transformers are toroidal, it does not find its way into the actual audio output, so I don't worry about it at all.
690559
Could be a defective unit. Mine will sometimes make a very slight hum (ear right next to the unit) but even when I'm lying in bed sleeping other than the reassuring click that it turned on, I can't hear the hum. I also am only drawing... ~11A on the heaviest circuit, if you're pulling more than that it could explain a louder noise
1633717
No noise or hum - I forget it's even there unless it's doing it's self test (about 5 seconds) then it's quiet again. South Florida.. we have lots of power interruptions and it's been a blessing.. I know it has saved my computer time and again.
1326998
Is the hum coming from the power adapter itself? If so, it might be getting ready to go bad. Replace before you have a fire. If the hum is from the speakers, re-post and I might have some suggestions for that as well.
653612
Sounds like it needs to be replaced. My subwoofer turned on just fine (little bit of a hum though).
1328919
I notice zero AC hum or any whine. I would use this again. I will pass on stay clear of tranmittion over AC wiring S/R units---I think Black Box was the one I used. It has a delay and gets hot.good luck
1688168
It is a bad unit. I had to send mine back.I just read the answer below mine, did you put the ferrite choke on the unit on the power cord? Hello! This unit should be ready to go out of the box. That hiss or hum could be heard over spoken words too. If you can send it back.
1705081
i've never noticed a hum. The red LED is a bit distracting, but I just turn it away from my line of sight. Seems to work just fine overall.Note: I am not an audiophile and don't hear frequencies much above 10 kHz. Sometimes other people hear things that I don't. FYI.
1741343
have you tried what Wm Mcbride suggested? I am considering buying the AT-PL 120.I have a Technics SL 23. Without connecting the ground wire will give the HUM!
342490
That long whistle sound pops on when power supply is not sufficient. At least from my experience. Try a much lower power draw device on it like a mini Christmas light set and see if the problem persists.
2222571
No, not normal - Have you checked your wiring, ground, etc? Are the green and blue lights glowing properly? I have two of the surge protectors- One since 2003 and there is no hum... I would return it.... Monster Cable will not honor a warranty by a seller they do not certify. Amazon is certified, but most of the merchants selling the product at a cheaper price are not.