This 60 Hz hum is driving me crazy

Well, it is not the speaker cable. Have you tried switching between the 4 & 8 ohm taps?

Great suggestion...and yes, forgot to mention I tried both 4 and 8.

Could be a loose ground inside the amp. If you only can hear it when your ear is next to the driver and doesn't increase with gain, I wouldn't worry about it.

I'm too lazy to type the whole path of isolating 60hz hum, but if that hum is "ear to the speaker", quit doing that. 

Used the same videos as reference.  60 hz

@russ69 haha...well, as mentioned, I am in the smallest man cave ever. Its a converted walk in closet turned office/stereo room.  So even from a distance, I can hear it in between songs.  I know its not too big of an issue, but at this level of hi-fi I have certain expectations...otherwise i would just get a SONOS.

"but at this level of hi-fi I have certain expectations"

Then you you need to serious about the size of your room. I don't think you will get satisfaction inside a closet with any setup other than headphones.

So even from a distance, I can hear it in between songs.

If you hear it from your listening position, it’s got to get solved. P.S. I have never had a hum issue I could not solve. First step is isolating the problem. Isolate it, then I’ll give you some ideas.

Edit. If amp hums with just the speakers hooked to it, it's the amp. Tubes are always suspect. Is it in both channels? Did it always hum? You might need a call to Upscale.

 

You mentioned using an extension cord. Here is my question. Did you plug the cord into the same electrical circuit as the amp is already on? If there is trouble with that circuit, it may not matter what outlet you use IN THAT CIRCUIT. Make sure that the test circuit is on a different breaker. If that works, great. You get to hunt down a loose connection or who knows what.

@dill Agreed and thats the goal.  Looking to move next year but for now, the closet office is the only place I can set this up.  I have one of those....what do you call them again, oh yea, a wife, that doesn't want so much stuff in the living room.  Nor do I want it accessible to my 6 year old who loves to push buttons beyond their limits.  @4krowme  I used a plug pre remodel so I assume its on a different circuit.

Well crap, Now I Have a Hum.... but I can fix it. Building a new amp this week.

Unplug from 110v and power down the entire internet stack and see if that changes anything.

1. prior amp, no hum?

2. reconnect old/any amp to confirm the Prima amp is the source

3. both sides, or one side? if 1, that's easier to switch things one at a time, swap tubes, swap cables, swap inputs ...  if both sides ....

4. you have your own tube tester? even without a problem, you benefit for the rest of your life with a simple tube tester.

5. temp hook prima different location, small portable speakers, portable cd player, IOW, still hums in another location?

6. if all tubes test good, contact cleaner all tube pins and sockets

 

I had a hum years ago that I couldn't get rid of, until I removed the outlet from the wall.  It turned out that the ground wire, which is bare, was just barley touching the hot lead screw terminal in the box.  I just rearranged the Romex in the box slightly and the problem was gone.

@russ69 

LOL re "I'm too lazy to type the whole path of isolating 60hz hum, but if that hum is "ear to the speaker", quit doing that."

I had a hum like this and spent a lot of time in 3-way chat with the designer of my preamp and builder of my amp (both very smart guys) who both said it can be a pain in the arse to troubleshoot ground loop hums. I did get it sorted out though there is still a very slight hum (reduced about 80%) with my ear directly next to the speaker. SO--I don't do that!  I can't hear it from the listening chair. I am lazy and easily frustrated so I am sure there are things I might try to eliminate it, but as I said, I am lazy!

(reduced about 80%)

My main tools for finding a hum are a cheater plug and a pair of ground breaking RCAs. I take all my gear and put it on the floor and hook up one item at a time. I can usually find the culprit. Then I can work on that one piece of gear and find the solution. One of the toughest ones was an unpolarized two prong plug on a preamp. If it was inserted into the wall the wrong way, it would hum. The other way, no hum. Voila!

Good news is that your average multi-meter will measure this quite well.  Set it to AC, measure it and call Prima Luna.

I had the same problem a few years ago. Even took my amp to the shop because I thought it was coming from there. But there is this thing called DC Offset. You can google it. There's something in the wiring of your house. It's not your gear. I found the CMX -2 precision common Mode  AC line Filter with DC Offset Eliminator. You can find it on the Emotiva web site. Does not affect the sound and gets rid of the hum. Check it out.

thanks Coach.  This is great info.  Going to try a few more things but will def add this to the list if all else fails.

Yep, dc offset can be problem, check your house grounding system.

Now that I think about it, both plugs I used were new ones from remodel from contractors who I would never use again. Hmmmmmm...need to try another outlet...unless they compromised the entire home.

Another grounding issue I had was from the cable TV box. There was a splitter on the outside of the house, which needs to be grounded and it was, to the steel conduit/ main breaker panel just above it. But, that grounding clamp and steel pipe had been painted so it wasn’t making a good bond. The resistance from the splitter to the pipe should have been 0 Ohms, but it was measuring about 10 ohms iirc, which isn’t much, but it was enough to cause the cable box to hunt for a better ground inside the house, inducing some hum. Once I cleaned everything with a wire brush on the outside of the house and got a good bond measuring 0 Ohms, the problem was solved.

There is also a product made by iFi for the stated problem. Same idea as Emotiva. We will all be anxious to hear what you discover.

iFi DC Blocker if Emotiva DC Offset Eliminator is unavailable.  Audiolab has a similar product too.

1. you need to find out whether this model is buzzing from other users or not (cheap transformers and especially input torus - let all the dirt out of the network) ...
2. if only your copy or only in your house is buzzing - this is a dirty network - TAKE Bail filters, isolation transformers, cables ... if something helps - then buy it (do not buy what you have not heard - sellers will be deceived)

Glad I could help.

Get one of those cheap yellow outlet testers at Home Depot and see if the new outlets where wired correctly.

If your using tubes from the previous owner you have no idea how many hours they have on them.  I would say replace all the tubes and go from there.  I bet that solves your issue.  Others commented on a possible DC Offset issue but this usually manifests itself as a humming from transformers in your equipment and not a sound through the speakers as you describe.  Before you do anything...replace the tubes as that to me is the most obvious cause.  

 

@dill got the little $6 yellow tester (figured it is good to have regardless).  All outlets I have been using were OK.

Also moved the amp out of my mini man cave into the living room and plugged into another outlet....and the hum is still there!!!

I ordered the iFi DC blocker from Amazon to check that next.

My new speaker cables came in too, and no help.

If the DC Blocker fails, I will try replacing the tubes.  Does anyone recommend a solid place for both price and good tube reputation?  

 

For tubes I suggest Jim McShane or Brent Jessee. Both have websites and are good sources for tubes. Jim for good prices, Brent for the best.

You might have a ground issue inside the amp. I had one in my phono stage that was fixed by removing some paint from under the chassis ground wire. There was not enough bare metal exposed to make a good ground. The paint was acting like an insulator.

Thanks @dill! I will google their names.  There is no phono stage on mine but there is a ground mount on the back for a phone preamp.  To your point:

Talking to someone from Upscale service.  I mentioned that I lifted the ground but he still thinks its a ground loop.  He basically told me to Google it and try other things.  Haha

 

My phono stage is a separate, stand alone unit plugged into an integrated amp via interconnects and is about 1 1/2'away from the amp. The ground wire inside was insulated by the paint. I took off the ground wire, scraped the paint off and bingo, no more hum.

That is a good idea steakster!

Got the DC blocker. Was excited because I turned on amp and no buzz. Walked away and came back a minute later. Hi Buzz!  Didn’t work. Got the BuzzX coming in too. Doubt it will work but glad Amazon makes it easy return. 

Separating the wheat from the chaff in an advice column can be helpful. No offensive intended here. Working mostly with DC circuits and some AC circuits, I found out a lot of lies that sounded right but would lead you in the wrong direction. >>>>"Ground is ground the world around"<<<< was one of my favorites. Sounds catchy and true, but no, it isn’t.

I am sorry that the DC blocker didn’t work for you. Would have made things simpler. One thing that you mentioned was that there is Still Hum when using the amp on a different circuit in the house. That definitely points to the amp at this moment. Replacing the tubes may be a good idea, yet I would be inclined to start only with the rectifier tube if the amp uses one.

Try to isolate One Thing at a Time. That is what we did in my job, and though it might seem tedious, it won out in the end... most of the time. As others have said, it can be difficult to find a hum problem, but at least there are a few things that you can do on your own.

 

I look forward to following your progress.

@steakster I have too much going on to do that but instead, I plan to pack it up and take it into my office (which was built in the 60s) so I hope the electrical there has good grounds.

I knew it wouldn't work, but tried it anyway.  DC Block paired with the Hum Eliminator did not work.  Also notice that the Hum will increase a touch if I turn the volume up.  Is that a 120 Hz?  

Really confused now.  Talking to someone at UA, he thinks its a groundloop and new tubes won't help.  Spoke to a local dealer here and he thinks the tubes need to be changed.  

I am trying everything I can before taking her in to the doctor. 

UGH!!  Fresh set to tubes from McShane...perhaps a slight decrease in buzz, but it's still there.

Looking for Bay Area recommendations for stereo repair.  I don't know what else I can do.

FYI, Upscale Audio was completely useless and the customer service was quite half ass.  I do appreciate that they got back to me, but their replies were very "figure it out or Google it."  Which I did.

Hums, buzzes and all that. Been there done that. Ditched tubes, went all SS and never looked back. Liked the tube “sonics” but “noise” bugs the Shitake out of me. The issue is most likely your household. It literally could be a bad plug or light switch somewhere on the circuit. Another thing to look at is any LED bulbs on the circuit or dimmers. Notorious. 
 

 

 

Ooooh.  I have LEDs and dimmers.  But I took the unit to my condo complex's main lobby and plugged in there.  Got the buzz.but there are LEDs galore.  Maybe I need to take it to my office that was built in the 60s

I just got a new to me, Prima Luna Prologue Premium Integrated tube amp. Sounds great, but there is a "ear to the speaker" 60 Hz hum. Hum sounds the same if I adjust volume +-/  The only thing I have connected is a Parasound Zdac.  Speakers are Rega RS1 Here is what I have tried:

1. I disconnected the Zdac so it was just the PL connected to the speakers with no other inputs. Hum still there.

Shorting the RCA shell and center conductor would be the best. If it is floated it “could” be more noisy, but it should also be something like 100k ohms.

Whatever a Zdac is, then leave it connected, or connect up a 1/8” to RCA cable and plug and iPhone into that aux input. The later is probably best, as then you have an A/B to know it is not the Zdac. 

 

2. While Zdac still disconnected, I use a 3-to-2 prong adpater to determine if its a ground loop.  Still there.

reconnect that Zdac.

 

3. The outlet is a new one added from our remodel.  So I used an extension cord and plugged into an original outlet to see if the electricity was "dirty."  Hum was still there. 

Dirty? It would not be dirty at 60Hz. Maybe 120, 180 Hz, etc, could be dirty, but the power should be 100% (or 99.9999% at 60 Hz.)

Now here some possible culprits.  

* The stereo is perhaps set up in the smallest man cave in California.  The speakers are about 2 feet away from preamp.  I will try moving speakers further.

That should not do anything different.

The size and distance does not affect the hum.

 

* I am using crappy Amazon 12 AWG cables.  I have some better ones coming from Morrow Cables. 

They should not do anything different. Amazon copper is the same as other copper. (It all comes from the dust of stars.)

 

* The stereo is in front of the panel that our internet wiring comes in through (I am in a condo complex).  There is no wireless there, but perhaps I should set up system somewhere else to try.

Wireless is way higher than 60Hz. But it doesn’t hurt to try and extension cord.

 

* I am using the tubes from the previous owner...do I just buy a set of new tubes?  

No. That is the last thing you need.

 

Is there anything else I should try?  Thanks in advance.

I have Zu Def 4s with built-in powered subs. One of them started to buzz. I bought a relatively inexpensive hospital grade isolation transformer made by Tripp Lite. No buzz. Obviously YMMV.