Hum…help

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Illaheman

Hum…help
« on: 29 Dec 2021, 05:55 am »
Amp running, hooked to speakers, not hooked to preamp
no hum.

Amp running, hooked to speakers, xlrs to pre-amp,
@60 hz Hum.

Amp running, hooked to speakers, rca’s to preamp,
@60 hz Hum

Volume control makes no difference in volume or amount of hum
All plugs in same outlet

I’ve tried the humx…..no difference.
Unhooked everything, hooked it back up piece by piece?
Swiped XLRs..same results.
Kismet Stratos
Hegel P20 pre-amp

Is the problem the amp, preamp, speaker cable, what else?
Should I not worry?

DannyBadorine

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Re: Hum…help
« Reply #1 on: 29 Dec 2021, 03:42 pm »
What setting is the preamp on? Phono?  Is the record player ground cable hooked up?  Check to see if the hum goes away on different preamp settings (Aux 1, Aux 2, etc.)
Next, make sure that the preamp and amplifier are plugged into the same Edison outlet circuit.  You could have a ground loop if they are on different circuits.

lazydays

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Re: Hum…help
« Reply #2 on: 29 Dec 2021, 09:44 pm »
Amp running, hooked to speakers, not hooked to preamp
no hum.

Amp running, hooked to speakers, xlrs to pre-amp,
@60 hz Hum.

Amp running, hooked to speakers, rca’s to preamp,
@60 hz Hum

Volume control makes no difference in volume or amount of hum
All plugs in same outlet

I’ve tried the humx…..no difference.
Unhooked everything, hooked it back up piece by piece?
Swiped XLRs..same results.
Kismet Stratos
Hegel P20 pre-amp

Is the problem the amp, preamp, speaker cable, what else?
Should I not worry?

a sixty Hz hum can also be from your house current. Near impossible to get rid of. I'd swap all the cables going from the preamp to the amp. Then start swapping the inputs out one at a time. Next place to look is the wall receptical. Good place to start there is by swapping out power cables one at a time.
gary

Doublej

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Re: Hum…help
« Reply #3 on: 29 Dec 2021, 10:13 pm »
Using one of these will confirm that your receptacles are wired correctly.

https://www.amazon.com/Gardner-Bender-GFI-3501-Receptacle-Extension/dp/B00170KUPC





genjamon

Re: Hum…help
« Reply #4 on: 29 Dec 2021, 10:27 pm »
Sounds like a ground loop formed between preamp and amp.  Not easy to fix.  I have one between my Don Sachs tube preamp and my Kismet stereo amp that I have largely given up trying to resolve.  I was able to minimize it by re-wiring my power conditioner to ensure equal wire lengths between outlets and the circuitry (basically making sure as best I can that the preamp and amp are at the same ground/voltage potential relative to each other - which a difference in potential is a cause of a ground loop).  This made a significant difference in keeping it relatively quiet and unobtrusive when music is playing.  But it's still there. 


Illaheman

Re: Hum…help
« Reply #5 on: 30 Dec 2021, 03:16 am »
Interesting. Thank you. So do you just live with it. Any damage to be expected?
I’ve been leaving my Kismet on 24-7, but if I’m not going to listen to the stereo, I unhook one of the xlrs from the preamp and it silences it. It happens to be easy to reach.

It is a very low hum…and it disappears with music. I don’t like the idea of it harming my speakers. Should I be worried leaving it on and humming all the time?

Illaheman

Re: Hum…help
« Reply #6 on: 30 Dec 2021, 03:18 am »
a sixty Hz hum can also be from your house current. Near impossible to get rid of. I'd swap all the cables going from the preamp to the amp. Then start swapping the inputs out one at a time. Next place to look is the wall receptical. Good place to start there is by swapping out power cables one at a time.
gary

Helpful . Thank you

klaus@odyssey

Re: Hum…help
« Reply #7 on: 31 Dec 2021, 01:40 am »
Yes,  good advise all around...if you are using the XLR's and have some issues,  then I  can also do some more grounding for you as well....call me.

In general,  there are 2  kinds of hum / problems:  one is component interconnected / problem within the system.  Easy to catch as the hum will go up in volume when moving up the volume control....by far the nastiest though is the AC related one...many times it's a frickin needle in a haystack kind of deal,  and also easy to determine in that the noise level will stay the same regardless of volume control settings...this hum can be caused by pretty much anything,  including the PS of an amp,  yes.   and of course it could be a grounding problem anywhere in the system that ultimately hits it downstream into the amp / speakers.   Good news is that the amp is quiet when only connected to the speakers.  However,  as I mentioned before,  there are some additional internal groundings to be made as well..........

jjss49

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Re: Hum…help
« Reply #8 on: 31 Dec 2021, 03:53 am »
i have had similar problems with my stratos amp... xlr input is not usable, severe hum

the rca's work silently though, thank goodness

not sure why this happens on the odyssey amp, as i have no such issues with my hegel h20 nor arc 100.2, both with rca as well as xlr inputs

one thing i do notice is the stratos has much higher input sensitivity (which is neither good nor bad, just is...) - that been said, the rca input is dead silent while xlr is a hum fest  :|

Illaheman

Re: Hum…help
« Reply #9 on: 31 Dec 2021, 04:04 am »
I’ll try again on using the rca instead of the xlr.
Thank you for responding.

Illaheman

Re: Hum…help
« Reply #10 on: 31 Dec 2021, 04:10 am »

[/quote]
Yes,  good advise all around...if you are using the XLR's and have some issues,  then I  can also do some more grounding for you as well....call me.

In general,  there are 2  kinds of hum / problems:  one is component interconnected / problem within the system.  Easy to catch as the hum will go up in volume when moving up the volume control....by far the nastiest though is the AC related one...many times it's a frickin needle in a haystack kind of deal,  and also easy to determine in that the noise level will stay the same regardless of volume control settings...this hum can be caused by pretty much anything,  including the PS of an amp,  yes.   and of course it could be a grounding problem anywhere in the system that ultimately hits it downstream into the amp / speakers.   Good news is that the amp is quiet when only connected to the speakers.  However,  as I mentioned before,  there are some additional internal groundings to be made as well..........
Yes,  good advise all around...if you are using the XLR's and have some issues,  then I  can also do some more grounding for you as well....call me.

In general,  there are 2  kinds of hum / problems:  one is component interconnected / problem within the system.  Easy to catch as the hum will go up in volume when moving up the volume control....by far the nastiest though is the AC related one...many times it's a frickin needle in a haystack kind of deal,  and also easy to determine in that the noise level will stay the same regardless of volume control settings...this hum can be caused by pretty much anything,  including the PS of an amp,  yes.   and of course it could be a grounding problem anywhere in the system that ultimately hits it downstream into the amp / speakers.   Good news is that the amp is quiet when only connected to the speakers.  However,  as I mentioned before,  there are some additional internal groundings to be made as well..........

Klaus, thank you for weighing in. This is very frustrating. I’ll give you a call next week to consult and receive advice. Happy New Year! Ahead.
Jim

AzTunes

Re: Hum…help
« Reply #11 on: 7 Jan 2022, 03:09 am »
I had a hum condition pop-up a while back. The issue turned out to be a dirty tube socket. Used some Deoxit D5 on the tube pins and cycle it a couple times in the socket and reinstalled the tube. Hum went away the system is dead silent and sounds great. Maybe try the Deoxit treatment on your I/Cs, it’s an inexpensive treatment…