2. amps-preamps
  3. 1332600947

Hum from both speakers...This is New Please read.

Hi All, I would like to say I am new to channel after a long recovery from mid-fi! I am building a system in my home office. It consists of; Jolida 302crc (new tubes tried ), Jolida glass FX Dac, Jolida jd9, Rotel 2500 turntable..., pioneer elite pd65. Monitor Audio Silver RX2, Epos M Sub.
AQ rocket 88 speaker cable, AQ IC's.

So, the Jolida 302 is new. Since the first setup there has been a hum from both speakers. For the last month, I have been going insane throwing time and money at the problem. I have read, I think, every post on audiogon bout hum and the related links connected to other sites.

So, this AM, I am chasing the problem again, and I noticed that when I disconnect the negative speaker connection on the right speaker it goes away. Dead silent. Plug it back in and It returns. If I do this on the left speaker, it does not go away. Thes are biwired speakers and the hum only goes away on the right speaker, negative, low Freq posts. If I switch speaker sides, hum is still there but removing the right negative does nothing.

So,

Is it the negative speaker post on the amp?
Is it the negative speaker post on the speaker?
Is it the cable?

Could the ground in the amp or the speaker be loose on the right neg. post?

I know this subject has been beaten to death, but I think I am going to need counseling if I don't solve this.

Thanks in advance,

Troy
plosive
johnziomas's avatar
johnziomas
41 posts
 
I haven't read all replies, but I have been chasing a hum issue and just resolved it this morning so this might help.

In my case I isolated the problem to the preamp and it was causing the issue (ground loop,) I put a 3 to 2 prone adapter in the power cord and it's dead quiet now.


meerzistar
232 posts
 
Wire connectors are what I suspect first, ones that just aren't isolated well enough allowing them to pick up interference, or they were damaged. In one case I got some that were bad from the get go after un-packaging them. Some amplified sources are more susceptible one set of connections might work perfectly well on one source and may not on another. Also take care while removing them in confined spaces they can be easily damaged. A dap of dielectric grease can save a lot of headaches. 
r1oster's avatar
r1oster
5 posts
 
I had a hum I chased for months . Finally noticed a flicker in the house lights and called DTE to come out to check my service line , the neutral leg had corroded and caused the problem . They replaced the connectors on the house and transformer and all has been good .
oddiofyl's avatar
oddiofyl
3,825 posts
 
That's great to hear they took care of you.  While this thread is fresh I wanted to share a weird experience I had recently.  I was listening one night and every 20 seconds I heard a noise, not quite a hum and not quite a buzz.  It was strange, it lasted just a second or two and came back every 20 or 30 seconds.  I had just re-tubed my amps, Quicksilver Mid Monos so I suspected my preamp , a c-j Classic 2SE which is tough on tubes.  I replaced the 6922 with an EH and also a NOS Philips 6dj8 and the problem was still there.   I had also recently changed all the light bulbs in my house to LED so turned them all off and it was still there. .....frustrated , I began unplugging every  thing in the house one by one......It turned out to be my son's Ethernet on Ac adapter which uses the house's wiring to transmit data.  He needed it for his PS4 because Wi-Fi just wasn't fast enough.  I pulled an Ether net cable through the floor, problem solved.  Just goes to show sometimes it's the component but sometimes it's the environment it's in   
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