Speakers humming (APPJ Tube Amp + Pioneer SP-BS22LR)

[audiolistenr]

Excuse me for being a bit of a novice.

When connecting my APPJ Tube Amp + Pioneer SP-B22LR speakers to my TV or Projector via a 3.5mm Male to 2-Male RCA adapter, I get this incessant humming sound. That I don't get when connected to an Phone or Tablet.

Is it from interference? vibration?

Any suggestions for how to eliminate it, but keep the same setup?

 

[Bob]

you have a ground issue. you need to research the various ways to reduce the hum or eliminate
it. since I don't know your level of expertise I hesitate to make recommendations that could hurt
you.

also, you do not mention whether its tv output to the tube unit, or input to tube to TV.
you may even have an AVR in there. all present varying solutions.

 

[woodj]

vibration?

Not likely.
Have you tried disconnecting one or the other of the RCA plugs?

you have a ground issue. you need to research the various ways to reduce the hum or eliminate
it. since I don't know your level of expertise I hesitate to make recommendations that could hurt
you.

also, you do not mention whether its tv output to the tube unit, or input to tube to TV.
you may even have an AVR in there. all present varying solutions.

Very likely.

 

[audiolistenr]

you have a ground issue. you need to research the various ways to reduce the hum or eliminate
it. since I don't know your level of expertise I hesitate to make recommendations that could hurt
you.

Would an article like this be appropriate?
https://www.techhive.com/article/30...noises-from-your-audio-and-video-systems.html

also, you do not mention whether its tv output to the tube unit, or input to tube to TV.
you may even have an AVR in there. all present varying solutions.

It's the Audio Out from the TV (or Projector) via 3.5mm adapter to the Component In of the tube unit that feeds the speakers.

 

[Bob]

if both are three-prong AC power plugs, try using a common power strip. other than
that you are out of options. if other are two prong plugs, use strip and reverse the
plugs on one to see if there's reduction in hum. this is if and only if the dual prongs
are NOT polarized (large blades on one side) and can be reversed into a plug.

or if its not an apple then try reverse casting.

in all cases, you have a unique situation and will require a lot of research unless
you find the same problem solved using the same set of hardware and operations.

 

[doctor fuse]

I just changed the RCA cable in an old Dual 1009 turntable, as it had a hum/buzz in the right channel. It's gone with the new cable.

Have you tried different cables?

EDIT: Not so likely in your case, as the specs for the cable are not as critical as in a turntable.

 

[audiolistenr]

if both are three-prong AC power plugs, try using a common power strip. other than
that you are out of options. if other are two prong plugs, use strip and reverse the
plugs on one to see if there's reduction in hum. this is if and only if the dual prongs
are NOT polarized (large blades on one side) and can be reversed into a plug.

or if its not an apple then try reverse casting.

in all cases, you have a unique situation and will require a lot of research unless
you find the same problem solved using the same set of hardware and operations.

Thanks @Bob really appreciate the help.

Have you tried different cables?

Don't have too many spare cables, but I'll look to try that if the suggestion above is unsuccessful.

 

[whoaru99]

@audiolistenr

Almost certainly a ground loop as eluded to by others. Not uncommon, unfortunately, when you start tying lots of different stuff together.

Do you have cable TV (or maybe dish/satellite TV)?

Does your TV and or projector have Toslink optical digital output?

 

[Tim64]

I use unshielded interconnects on my appj mini watt with no hum issues. If I had to guess I would say it's the cable with a broken ground.

 

[audiolistenr]

@audiolistenr

Almost certainly a ground loop as eluded to by others. Not uncommon, unfortunately, when you start tying lots of different stuff together.

Does your TV and or projector have Toslink optical digital output?

My TV has a Toslink, but the APPJ doesn't support that connection.

I experimented with getting the main devices on the same outlet/surge protector and the humming noticeably decreased.
I wasn't able to get all devices onto the same outlet so some hum persists, I'll need to do some work juggling connections or buy a larger surge protector.

Thank you all for the help!

 

[Bob]

research. not going to recommend anything - don't want to be cause of your defibrillation if
you mess up.

 

[whoaru99]

My TV has a Toslink, but the APPJ doesn't support that connection.

I experimented with getting the main devices on the same outlet/surge protector and the humming noticeably decreased.
I wasn't able to get all devices onto the same outlet so some hum persists, I'll need to do some work juggling connections or buy a larger surge protector.

Thank you all for the help!

A larger surge protector is not going to fix this.

I understand the APPJ doesn't support digital input but Toslink to analog converter can be had pretty inexpensively, and may well give the ground loop isolation you need.

Otherwise, if you experiment with temporarily disconnecting the CATV feed from your TV or cable box, see how that goes.

CATV installations are notorious for not having the incoming feed bonded to the premises wiring as it is supposed to be by Code. That is a major contributor to ground loop issues in mixed stereo/AV systems.

This can be fixed rather than using cheater plugs as some are eluding to. But, you gotta invest a little skin in the game to sleuth out the root cause.

 

[woodj]

A larger surge protector is not going to fix this.

Sure enough.

 

[audiolistenr]

A larger surge protector is not going to fix this.

I understand the APPJ doesn't support digital input but Toslink to analog converter can be had pretty inexpensively, and may well give the ground loop isolation you need.

Otherwise, if you experiment with temporarily disconnecting the CATV feed from your TV or cable box, see how that goes.

CATV installations are notorious for not having the incoming feed bonded to the premises wiring as it is supposed to be by Code. That is a major contributor to ground loop issues in mixed stereo/AV systems.

This can be fixed rather than using cheater plugs as some are eluding to. But, you gotta invest a little skin in the game to sleuth out the root cause.

So connecting all devices into a single surge protector plugged into a single socket will not prevent a ground loop. Why is that?
My understanding is quite weak here.

I'll try some of your suggestions regarding unplugging the Cable connection from the box/TV and see how that goes.
As well as look into an analog converter (instead of a larger surge protector).

Much appreciative for the help!

 

[Bob]

ground loops have lots of reasons. one is a missing ground connection - typically
from turntable to preamp. second, devices often have multiple ground systems and
require each and every ground system to behave properly, first by design then by
practice.

you might try to find a device that isolates the signal coming out of the TV. an optoisolater
would work unless there's a whole bunch of information missing that accounts for the
problem and this would be a red herring.

with regards to your strip description, read up on grounds and go from there.

 

[whoaru99]

So connecting all devices into a single surge protector plugged into a single socket will not prevent a ground loop. Why is that?
...

Because there are other potential grounding paths besides the power cords (such as the shield of the CATV coax). If they are not all at same/similar potential you get currents that can cause noise/hum/buzz, amongst other things.

 

[audiolistenr]

Thanks for the extra detail!

 

[woodj]

one is a missing ground connection - typically
from turntable to preamp.

That's not a ground loop, but lack of ground.

 

[woodj]

Because there are other potential grounding paths besides the power cords (such as the shield of the CATV coax). If they are not all at same/similar potential you get currents that can cause noise/hum/buzz, amongst other things.

Absolutely.

 

[Bob]

correct two different ground systems with no common ground is loops.

sorry for not adding an "s".

other countries, you can have multiple ground systems not interconnected
and it would still work, or in the US, a completely separate audio system
with multiple internal ground systems, not interconnected and it would not
hum because there's no missing ground. they are completely isolated
from each other such as iso-optically.