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post #1 of 29 Old 01-19-2019, 09:23 AM - Thread Starter
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Dayton spa500. Lots of hum through the sub until i yank the RCA feed out. Then its silent. When it does happen w RCA plugged in, the hum gets louder w the amp volume.
I’ve tried a ground loop isolator which helps, but doesn’t resolve things totally.
Can I somehow fix this?

Ive tried multiple rooms/circuits and different sources. However, both sources are AVRs that feed an RCA wallplate which then carries the signal over co-ax to another wall plate, then RCA to the amp.
Could it be the coax to rca connections?

Last edited by TexmasterPEB; 01-19-2019 at 09:42 AM.
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post #2 of 29 Old 01-19-2019, 10:01 AM
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Well, I think you answered the question yourself.
Why in and out of a bunch of wall plates?
Don’t do that.

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post #3 of 29 Old 01-19-2019, 10:07 AM - Thread Starter
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So i should run an RCA cord across the floor of my room?
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post #4 of 29 Old 01-19-2019, 10:21 AM
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Why don’t you try that to see if the hum goes bye bye.

If it’s still there after trying that, I’m confident we can resolve the issue.

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post #5 of 29 Old 01-19-2019, 10:55 AM - Thread Starter
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Will need to track down some female to female rca connectors, as I don’t have a long enough cable to do that. And I can’t drag the 9.5cu ft sub to the av cab, as everything is built in and pulling the receiver is a disaster.
Will report back in in a day or so.
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post #6 of 29 Old 01-19-2019, 11:11 AM
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I do feel your pain!

...An A/V system is never completely finished...

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post #7 of 29 Old 01-22-2019, 02:29 PM - Thread Starter
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Direct rca from avr to sub plate amp; same hum. If I dial the gain down to 4.5 out of 10 on the amp, the hum becomes inaudible.
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post #8 of 29 Old 01-22-2019, 02:41 PM
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I have the same exact problem and just accepted it after a while I settled with a lower gain, therefore a less loud hum.

I hope one can share some golden tips to resolve this matter, I also tried an other circuit and had no luck.

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post #9 of 29 Old 01-22-2019, 03:22 PM - Thread Starter
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Originally Posted by IMWhizzle View Post
I have the same exact problem and just accepted it after a while I settled with a lower gain, therefore a less loud hum.

I hope one can share some golden tips to resolve this matter, I also tried an other circuit and had no luck.
I cant live with 4.5... that really limits the bass output, especially with a power hungry 18.
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post #10 of 29 Old 01-22-2019, 04:39 PM
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Originally Posted by TexmasterPEB View Post
Direct rca from avr to sub plate amp; same hum. If I dial the gain down to 4.5 out of 10 on the amp, the hum becomes inaudible.
Are you positive that all power cords are plugged into wall outlets that feed back to one circuit breaker.
I’m aiming to bet that this is your problem. But I would take the time to turn off that breaker, then note what other receptacles, appliances, and lights/dimmers share the same breaker.

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post #11 of 29 Old 01-22-2019, 05:59 PM - Thread Starter
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Its the same circuit, confirmed via breaker.

I just installed a higher quality ground loop isolator that I bought along with my rca adapters, and the hum vanished. I guess the PAC isolator that I’ve been using wasnt doing the trick. Now i have to find whats causing the ground loop. But it seems really odd that I had this issue in two room (two circuits).
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post #12 of 29 Old 02-02-2019, 01:15 PM - Thread Starter
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Aaaaaand the hum is back, out of the blue. It just auto turned on while watching TV, and that is when it came back.
I think its time to just get another amp.
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post #13 of 29 Old 02-02-2019, 07:14 PM
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Quote:
Originally Posted by TexmasterPEB View Post
Dayton spa500. Lots of hum through the sub until i yank the RCA feed out. Then its silent. When it does happen w RCA plugged in, the hum gets louder w the amp volume.
I’ve tried a ground loop isolator which helps, but doesn’t resolve things totally.
Can I somehow fix this?

Ive tried multiple rooms/circuits and different sources. However, both sources are AVRs that feed an RCA wallplate which then carries the signal over co-ax to another wall plate, then RCA to the amp.
Could it be the coax to rca connections?
RFI and EMI can easily hitch hike a ride onto coax cable. The coax needs to be isolated from everything else.
Can you post everything that is connected and how it’s connected. Do you have a cable set top box connected?

Espo77's living room equipment: RECEIVER: Yamaha RX-A3030- SPEAKERS: Boston Acoustics M350, M25 center, surrounds, and front heights-
BLU-RAY: Oppo BDP103D- SUBWOOFER: HSU VTF-15H MK2- dedicated circuits for A/V- TV: Vizio P55C-1
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post #14 of 29 Old 02-02-2019, 07:22 PM
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...also, you never clarified, is there anything else sharing this circuit?
You also said “sources are two receivers”. What does this mean? Can you try just one?

Espo77's living room equipment: RECEIVER: Yamaha RX-A3030- SPEAKERS: Boston Acoustics M350, M25 center, surrounds, and front heights-
BLU-RAY: Oppo BDP103D- SUBWOOFER: HSU VTF-15H MK2- dedicated circuits for A/V- TV: Vizio P55C-1
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post #15 of 29 Old 02-02-2019, 07:48 PM - Thread Starter
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Quote:
Originally Posted by Espo77 View Post
Quote:
Originally Posted by TexmasterPEB View Post
Dayton spa500. Lots of hum through the sub until i yank the RCA feed out. Then its silent. When it does happen w RCA plugged in, the hum gets louder w the amp volume.
I’ve tried a ground loop isolator which helps, but doesn’t resolve things totally.
Can I somehow fix this?

Ive tried multiple rooms/circuits and different sources. However, both sources are AVRs that feed an RCA wallplate which then carries the signal over co-ax to another wall plate, then RCA to the amp.
Could it be the coax to rca connections?
RFI and EMI can easily hitch hike a ride onto coax cable. The coax needs to be isolated from everything else.
Can you post everything that is connected and how it’s connected. Do you have a cable set top box connected?
I removed the coax from the equation by running the long rca across the floor from receiver to amp. It still hummed.

I used to have this amp in my theatre room, connected to avr1. It hummed. Its now in the living room, connected to avr2 and it still hums.

Both setups were/are avr to rca wallplate via rca. Wallplate to rca wallplate via coax. Wallplate to sub amp via rca. As mentioned above, i did completely bypass the coax in the avr2 setup with a long rca and it still hummed.

AVR2 setup is smart tv and blu ray to avr via optical. No cable anywhere.

Last edited by TexmasterPEB; 02-02-2019 at 07:56 PM.
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post #16 of 29 Old 02-02-2019, 07:50 PM - Thread Starter
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Originally Posted by Espo77 View Post
...also, you never clarified, is there anything else sharing this circuit?
You also said “sources are two receivers”. What does this mean? Can you try just one?
The current circuit has the avr, tv, wifi repater (which i’ve unplugged), a dayton external amp which powers an outdoor sub, and a lamp.
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post #17 of 29 Old 02-02-2019, 09:03 PM
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Originally Posted by TexmasterPEB View Post
The current circuit has the avr, tv, wifi repater (which i’ve unplugged), a dayton external amp which powers an outdoor sub, and a lamp.
Does the lamp have a dimmer? That sort of thing can be a noise source. Simple enough to unplug it to check.
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post #18 of 29 Old 02-03-2019, 03:24 AM - Thread Starter
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No dimmer on the lamp
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post #19 of 29 Old 02-03-2019, 03:31 AM
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Probably a grounding issue - on the sub's power cable, if it has 3 prongs, try using a "cheater" temporarily (which lifts the ground) or run the power cable back to the same power source as the rest of your gear.

The solution is to put an isolator on the RCA cable, or, the power (something like a Hum-X).
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post #20 of 29 Old 02-03-2019, 05:23 AM
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Quote:
Originally Posted by TexmasterPEB View Post
Its the same circuit, confirmed via breaker.

I just installed a higher quality ground loop isolator that I bought along with my rca adapters, and the hum vanished. I guess the PAC isolator that I’ve been using wasnt doing the trick. Now i have to find whats causing the ground loop. But it seems really odd that I had this issue in two room (two circuits).
Can you please tell me what isolator you purchased? Thanks
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post #21 of 29 Old 02-03-2019, 11:32 AM - Thread Starter
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Probably a grounding issue - on the sub's power cable, if it has 3 prongs, try using a "cheater" temporarily (which lifts the ground) or run the power cable back to the same power source as the rest of your gear.

The solution is to put an isolator on the RCA cable, or, the power (something like a Hum-X).
I am already running an isolator on the rca amd it still hums. I dont have a cheater plug, but I’ll grab one next time i’m at a big box.

The isolator is an XtremPro Hi-end Ground Loop Noise Isolator / Filter for Car Audio / Home High-fidelity System - Black (65042)
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post #22 of 29 Old 02-03-2019, 01:59 PM
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Originally Posted by TexmasterPEB View Post
I am already running an isolator on the rca amd it still hums. I dont have a cheater plug, but I’ll grab one next time i’m at a big box.

The isolator is an XtremPro Hi-end Ground Loop Noise Isolator / Filter for Car Audio / Home High-fidelity System - Black (65042)
If you are willing to sacrifice a power cable for a "Temporary Solution" you can simply cut off the ground plug.
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post #23 of 29 Old 02-03-2019, 02:17 PM - Thread Starter
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I know. But with the frequency at which I go to Lowes, it won’t be long. 🙂
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post #24 of 29 Old 02-03-2019, 02:20 PM
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Quote:
Originally Posted by TexmasterPEB View Post
Dayton spa500. Lots of hum through the sub until i yank the RCA feed out. Then its silent. When it does happen w RCA plugged in, the hum gets louder w the amp volume.
I’ve tried a ground loop isolator which helps, but doesn’t resolve things totally.
Can I somehow fix this?

Ive tried multiple rooms/circuits and different sources. However, both sources are AVRs that feed an RCA wallplate which then carries the signal over co-ax to another wall plate, then RCA to the amp.
Could it be the coax to rca connections?
my cable box was culprit
60hz isolator helped a lot
i believe it was this one
https://www.amazon.com/Viewsonics-VS.../dp/B0017I3K9M
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post #25 of 29 Old 02-03-2019, 04:39 PM
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my cable box was culprit
60hz isolator helped a lot
i believe it was this one
https://www.amazon.com/Viewsonics-VS.../dp/B0017I3K9M
He told us that he’s not using a cable box.

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post #26 of 29 Old 02-05-2019, 03:12 PM - Thread Starter
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Brief update; I tried a TrippLite Ultrablok428 in the outlet feeding the SPA500 and it still hums. Will try the two prong ground lift tomorrow.
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post #27 of 29 Old 02-07-2019, 02:18 PM - Thread Starter
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Ground loop isolator on RCA to amp, and ground lift outlet plug adapter and it still hums.

Last edited by TexmasterPEB; 02-07-2019 at 02:21 PM.
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post #28 of 29 Old 02-07-2019, 02:58 PM
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Maybe the Dayton subwoofer amplifier is defective..

Just my $0.02...
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post #29 of 29 Old 02-07-2019, 03:07 PM - Thread Starter
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Maybe the Dayton subwoofer amplifier is defective..

Just my $0.02... [IMG class=inlineimg]/forum/images/smilies/wink.gif[/IMG]
Agreed!

I’ve had this plate amp and two rack amps from them, and of the three only one of the rack amps has been trouble free.
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