Damn ground loop - sorry, can't diagnose myself :(

Pycroft

I know, I know...I hate these threads too Any help you can give would be appreciated.

Integrated Amp: Music Fidelity M6i
Buzz occurs ONLY when I'm in the HT/Aux switch - currently to HT Bypass mode.

My HK avr354 is plugged into the HT spot. Other sources = CD, Dac/Phono Preamp is plugged into the tuner section. HT is the only buzz.

Cable is not plugged into the M6i. Those are the only things. Amp is plugged directly into the wall. The HK/CD is plugged into a Monster power conditioner. Lots of other things in there - Cable, turntable, TV, etc.

Things I've tried: I've unplugged the HK AVR, still a buzz (Makes no sense why the only thing that's plugged into the spot that's got the buzz, still buzzes when unplugged. I have also tried actually unplugging the cable from the wall just in case (I know it's often the issue).

The buzz is constant, and does not change volumes when volume is increased, and is still audible when volume is turned all the way down.


Any ideas, please share!

Thanks,

James

treitz3

Pycroft wrote: »

The HK/CD is plugged into a Monster power conditioner. Lots of other things in there - Cable, turntable, TV, etc.

Hello James, Look at this as a culprit.

Tom

Pycroft

I'll do one at a time. If the problem may be the HK AVR into the Monster Power conditioner - would plugging that directly into the wall possibly solve?

James

Pycroft

Alright -

I plugged the AVR into a different socket that the Amp/Monster are not going to - no change. I checked connections of all IC's to the back of the Integrated, no difference. I will next try different IC's...if that doesn't work, what's next?

James

treitz3

Unhook the cable unit to the Monster (power and cable). Make damned sure that nothing else is connected from the cable box to any of the rest of the system and provide feedback.

Tom

treitz3

If it remains, before offering feedback, do the same thing with the phono. Unplug everything connected to the LP player and see if the issue remains. Then report back please.

Tom

cnh

Sometimes you just can't isolate those things and a cheater plug might work (using a two prong adapter on a 3 prong cord). That's what I have on my Nak pre-amp. It was the "only" thing that worked. But even that does not always do the trick. But it's simple.

cnh

Pycroft

Okay -
I unplugged EVERYTHING. The only thing plugged into the one wall socket was the Integrated Amp, and the only thing into the other wall socket was the AVR. The only IC's were from the AVR to the HT of the Integrated.

Bad news I guess - Still a buzz. If this matters - when I moved the switch from HT to AUX, the buzz stopped, it only buzzed when it was in HT mode.

I read that using the 3 prong to the 2 prong adaptor is bad?

James

cnh

I've been running my Nakamichi pre like that for a couple of years. If it's bad, the Nak doesn't know it! I'm NOT saying this is a great fix but plugging one in and trying it won't hurt anything as an experiment.

The other option is having the cable boys come by and make sure that THEIR cable is PROPERLY grounded. I know mine is NOT! As I understand it, if things are not properly grounded it affects EVERYTHING in the house. And there is no escape. If I am wrong, then someone should jump in and correct my understanding. No problem with that.

cnh

Pycroft

My cable and TV aren't even plugged into the wall, and there's still a buzz. Is it possible it's still a problem? I've used the adaptor before, but was just reading before posting and said it shouldn't be done? I know nothing about most things, so that wasn't a statement from me

James

cnh

Is your internet through a TV cable modem? And if so is that also OFF? Where's Lightman1 when you need him?

cnh

bigus

Pycroft wrote: »

I know, I know...I hate these threads too Any help you can give would be appreciated.

Integrated Amp: Music Fidelity M6i
Buzz occurs ONLY when I'm in the HT/Aux switch - currently to HT Bypass mode.

My HK avr354 is plugged into the HT spot. Other sources = CD, Dac/Phono Preamp is plugged into the tuner section. HT is the only buzz.

Cable is not plugged into the M6i. Those are the only things. Amp is plugged directly into the wall. The HK/CD is plugged into a Monster power conditioner. Lots of other things in there - Cable, turntable, TV, etc.

Things I've tried: I've unplugged the HK AVR, still a buzz (Makes no sense why the only thing that's plugged into the spot that's got the buzz, still buzzes when unplugged. I have also tried actually unplugging the cable from the wall just in case (I know it's often the issue).

The buzz is constant, and does not change volumes when volume is increased, and is still audible when volume is turned all the way down.


Any ideas, please share!

Thanks,

James

You might want to disconnect everything and then hook up each unit one at a time.
99% of the time it's the coax cable but it could be a bad cable or unit.
If it is the coax cable that's causing the problem, you might also want to look at HumX or something similar.
good luck.

treitz3

Just to be sure, are any cable runs going to or from either plugged into the system in any way? This has nothing to do with power cords.

Welcome to the forum, bigus.

Tom

Pycroft

Cable is through RCN cable - typical wire from home to Cable Box to TV. When I did the last test, I unplugged everything - Cable/TV/BD Player/CD/Turntable - the only things in the wall or connected to the M6i Integrated was the AVR plugged into the HT/Aux that is buzzing.

James

Pycroft

Cable box goes to the TV, but the TV/Cable were unplugged, and I've never sent the cable through the AVR, so the answer is no Tom. Thanks.

James

ALSATIAN in USA

use "3 to2"prong adaptor (Less than $3 at walmart) for all!!!! I done that and everything is ultra-quiet! (I hope my dogs don't pee on my stuff)!

treitz3

Pycroft wrote: »

.....the only things in the wall or connected to the M6i Integrated was the AVR plugged into the HT/Aux that is buzzing.

I'll trust that you did the last test to a "t" with what I asked. If this is the case, we have now narrowed it down to two components. It's the integrated or the AVR. Have you tried hooking both up to the speakers separately to see if the issue remains with either one? If so, which one or neither?

Tom

bigus

Pycroft wrote: »

I know, I know...I hate these threads too Any help you can give would be appreciated.

Integrated Amp: Music Fidelity M6i
Buzz occurs ONLY when I'm in the HT/Aux switch - currently to HT Bypass mode.

My HK avr354 is plugged into the HT spot. Other sources = CD, Dac/Phono Preamp is plugged into the tuner section. HT is the only buzz.

Cable is not plugged into the M6i. Those are the only things. Amp is plugged directly into the wall. The HK/CD is plugged into a Monster power conditioner. Lots of other things in there - Cable, turntable, TV, etc.

Things I've tried: I've unplugged the HK AVR, still a buzz (Makes no sense why the only thing that's plugged into the spot that's got the buzz, still buzzes when unplugged. I have also tried actually unplugging the cable from the wall just in case (I know it's often the issue).

The buzz is constant, and does not change volumes when volume is increased, and is still audible when volume is turned all the way down.


Any ideas, please share!

Thanks,

James

You might want to disconnect everything and then hook up each unit one at a time.
99% of the time it's the coax cable but it could be a bad cable or unit.
If it is the coax cable that's causing the problem, you might also want to look at HumX or something similar.

good luck.

Pycroft

Tom,

The Integrated is powering the SSM9's, and the AVR has the SSM1, and Polk RT800's as surrounds. I haven't tried to play either with the hum. I have played the SSM9's with both CD's, Vinyl and Dac through my Furutech GT40. Would you suggest trying to hook the CD up the the AVR and play through just the other 3 speakers, or are you suggesting something else?

james

treitz3

I am suggesting to try to isolate the issue. From our discussions, we have seemingly narrowed it down to one of two things. The integrated or the AVR. One of the two (or both of them connected) has an issue with the ground loop. If we isolate which one it is, then we can figure out what to do.

Is it easy enough for you to hook up the same set of speakers to both units using the same source?

Tom

billbillw

Every time I've ever tried to mix my 2-ch with HT, I ended up with ground loop issues. In my case it was always something to do with the cable box. Doesn't matter if the cable is fed through through the AVR. It just somehow screws things up. Might try to see if the grounding block on your cable feed is tied into the ground your power meter.

Come to think of it, I had ground loop problem trying to feed my BAT preamp with my Onkyo's preouts.

I just get the feeling that AVRs don't like 2-ch preamps or integrated amps for that matter (especially ones with tubes in them ). They advertise the HT-bypass feature, but I haven't had any luck with it.

Pycroft

Treitz -

I have no source in right no, but i can plug my CD into both. Again - I've already used the integrated with other sources, so should I start with the AVR? Also, the AVR can't really handle the Sony SSM9's. I guess small volume is okay right?

When I play through my AVR only, I should unplug from the Integrated right? I'll wait to hear.

Bill, I'm not sure what that means

Thanks for the input so far guys!

James

cnh

Sounds like a plan! But I would assume, and correct me if I am wrong. That James has "probably" run the AVR by itself with no hum and also the integrated by itself, with no hum in the past. No?

cnh

Pycroft

The Integrated is new (About 2 months) and I have not used it once in the HT function. I've used the AVR with different amps, but not this one. I had a ground loop issue with the specific AVR once before, in a different home though (My Voorhees one that you were too CNH).

James

billbillw

Pycroft wrote: »

Treitz -


Bill, I'm not sure what that means

Thanks for the input so far guys!

James

Sorry, my thoughts were a bit scattered. I've edited the original post some.

As for the grounding block that I mentioned, that would be on the outside of the house, where the cable feeds into the house. There should be a ground/surge block where the feed comes from the street before it goes into the house. It should have a ground wire that ties into the ground strap that is tied to your power meter (big rod in the ground).

After reading your situation more, it might just be like I said, the tube pre-section doesn't like being fed from AVR.

treitz3

Pycroft wrote: »

I have no source in right now, but i can plug my CD into both. Again - I've already used the integrated with other sources, so should I start with the AVR? Also, the AVR can't really handle the Sony SSM9's. I guess small volume is okay right?

Yes, plug the source (in your case the CDP) into one, then the other. Do you hear a ground loop with either one? Lower volume is okay, play with no worries.

Now, if you hear no issues with either one.....plug just the two units together like you normally would and see if the ground loops rears it's ugly head.

Tom

cnh

billbillw wrote: »

Every time I've ever tried to mix my 2-ch with HT, I ended up with ground loop issues. In my case it was always something to do with the cable box. Doesn't matter if the cable is fed through through the AVR. It just somehow screws things up. Might try to see if the grounding block on your cable feed is tied into the ground your power meter.

Come to think of it, I had ground loop problem trying to feed my BAT preamp with my Onkyo's preouts.

I just get the feeling that AVRs don't like 2-ch preamps or integrated amps for that matter (especially ones with tubes in them ). They advertise the HT-bypass feature, but I haven't had any luck with it.

Hmmm. This pretty much syncs with one of the options Tom mentioned as well:

"...(or both of them connected) has an issue with the ground loop". Treitz

I'd say this sounds like a winner?

cnh

treitz3

Well, we have one more component that we haven't checked yet that is still in the loop. Let's see what James figures out and go from there. Ground loops are a *female dog*.

Tom

Dennis Gardner

Lift the grounds on your Odyssey amps. 3 to 2 adaptors or 2 prong cables, either way will work. That is the only thing that got the hum out of my Odyssey amps. My hum came from my Tivo to my AVR with HDMI to my Odyssey by RCA. Those that say that ground lift devices are bad don't understand that tons of gear is built with ground lift switches built in the design. Guitar amps, pro sound guys deal with it all the time.

Pycroft

Okay, No buzz when done separately. Dennis - I no longer have the Odyssey amps - I've gone simpler with the Musical Fidelity M6i integrated - just one piece instead of two.

I'm hoping something isn't actually malfunctioning in the integrated. Next step?

James

Dennis Gardner

If the amp has 3 prongs it is getting a different ground than the conditioned gear since it is plugged in directly.