Dx9 Hum

[terrys999]

I own the topping dx9.
Just noticed an hum sort of changing tone up down .
As soon as I turn it on both speakers are affected.
If I unplug xlr and rca sound goes.
xlr is louder than rca

I removed the earth ground for a minute to see if it cured it. Nope still same.
Obviously I reconnected the earth again
Anyone ?

Oh topping d70 and adi played without hum.
Anyone?

Update.
If i turn off power with switch on back ofthe dx9 and then take out rca from amp then touch rca with finger noise is louder huh.

Even with nothing connected from dx9 to amp touching the rca from the powered down dx makes speakers hum
What the????????
All my other dacs are silent.

Do I need a power cleaner?

 

[Roland68]

I own the topping dx9.
Just noticed an hum sort of changing tone up down .
As soon as I turn it on both speakers are affected.
If I unplug xlr and rca sound goes.
xlr is louder than rca

I removed the earth ground for a minute to see if it cured it. Nope still same.
Obviously I reconnected the earth again
Anyone ?

Oh topping d70 and adi played without hum.
Anyone?

Update.
If i turn off power with switch on back ofthe dx9 and then take out rca from amp then touch rca with finger noise is louder huh.

Even with nothing connected from dx9 to amp touching the rca from the powered down dx makes speakers hum
What the????????
All my other dacs are silent.

Do I need a power cleaner?

A power cleaner won't help at all here.

First, you need to list and describe exactly which devices are involved and how they are connected, from the source to the speakers, ideally with -> in between.

Even with nothing connected from dx9 to amp touching the rca from the powered down dx makes speakers hum
What the????????
All my other dacs are silent.

You mean there's no connection to the amplifier from the DX9?
Is there a connection (USB?) from the source to the DX9 and to another device that goes to your amplifier?

That sounds like a massive ground loop problem.

 

[terrys999]

OK
So I have now moved the dx9 in the middle of room.
It is plugged into the wall socket with audiolab 9000p along with cxn streamer .
Iam using toslink to the dx9.
There are 3 things connected.

I then can connect xlr to power amp .
Humming is louder.
Rca is not as bad but still hums.
Preamp volume does increase noise.
Dac mode is the same.

It's definitely not the amp.
Adi 2dac fs and d70 pro with a70 to amp either xlr or rca no noise at all.

I have switched all house appliances off

 

[KenA]

Do you get the same hum vai headphones, with Xlr and rca disconnected?

 

[Roland68]

OK
So I have now moved the dx9 in the middle of room.
It is plugged into the wall socket with audiolab 9000p along with cxn streamer .
Iam using toslink to the dx9.
There are 3 things connected.

I then can connect xlr to power amp .
Humming is louder.
Rca is not as bad but still hums.
Preamp volume does increase noise.
Dac mode is the same.

It's definitely not the amp.
Adi 2dac fs and d70 pro with a70 to amp either xlr or rca no noise at all.

I have switched all house appliances off

You can't be sure that it's definitely not the amplifier. A grounding problem always comes from multiple devices combined.
The fact that it doesn't occur, or isn't audible, in connection with your other devices, the ADI 2DAC FS and the D70 Pro with the A70, doesn't mean anything. The problem could just as easily exist, but not in the audible range, only in the measurable range.

Did the problem occur with the DX9 from the beginning?

It would be good to check whether the DX9 is defective. Do you have someone with an oscilloscope who could measure it?

Alternatively, I would test the DX9 in a completely different system, for example, at a friend's or dealer's.

 

[terrys999]

Headphones are no affected.
I change amp with cxa80.
Same noise.
I have used both amps before never had this noise.
Xlr is twice as loudish at a loss of what to do

 

[KenA]

No hum in headphones, same hum across two amps, same hum in both Xlr and rca. I’m thinking this suggests the dac has an error in its analog output stage, possibly a grounding issue.

 

[terrys999]

Ok
Now just sorted out cables
I was wrong . The CXA80 no noise.
When I connect audiolab amp noise is back.
But only with dx9
Now I don't know w
If ts the dx fault or audiolab.
Everything else is super quiet

 

[Roland68]

Headphones are no affected.
I change amp with cxa80.
Same noise.
I have used both amps before never had this noise.
Xlr is twice as loudish at a loss of what to do

No hum in headphones, same hum across two amps, same hum in both Xlr and rca. I’m thinking this suggests the dac has an error in its analog output stage, possibly a grounding issue.

The output stages for the preamplifier and headphone amplifier are the same on the DX9.

The output stages for XLR and RCA are also completely separate: 4 for balanced, 2 for RCA/SE.

 

[Roland68]

Ok
Now just sorted out cables
I was wrong . The CXA80 no noise.
When I connect audiolab amp noise is back.
But only with dx9
Now I don't know w
If ts the dx fault or audiolab.
Everything else is super quiet

Again, this doesn't necessarily have to be related to a defect. Ground loop problems are very complex and can occur in combination with two or more devices without any defect being the cause.

Ground loop problems are a very complex topic, even for the best experts.

 

[terrys999]

Ok so what do I do?
Would some sort of isolator solve it?

 

[terrys999]

Cxa amps work fine.
Audiolab 9000p doesn't like topping dx9 dac/amp

 

[Roland68]

Cxa amps work fine.
Audiolab 9000p doesn't like topping dx9 dac/amp

Do you have the DX9 gain set to low or high?

 

[terrys999]

Low gain.
Always.
Iam a little stuck as to what to do.

 

[Roland68]

Low gain.
Always.
Iam a little stuck as to what to do.

Unfortunately, it's a complex problem.
Since you connected the source device with Toslink and it is therefore isolated, that is also out of the question.

May I ask what country you live in? Regarding plug standards, mains voltage, etc.

 

[terrys999]

I live in the UK
Power is 240v
3 pin plug .

Just moved a few things around.
So to recap.
Topping causes noise when connecting to
Audiolab 9000p xlr is worse than rca.
The dx9 can connect to cxa80 and cxa60 dead silent no prob.

All other dacs
Adi2 dac fs
Topping d70
Audiolab mdac plus
Even irdac 2
All silent as the dead.

So the dx9 plays fabulously but not with 9000p.
It's go me beat.
Oh the headphones are silent too
No hum lovely silence

 

[Chagall]

Sorry, can't help - bumping for visibility though

 

[terrys999]

Yes you got the diagram right.
It seems that for some reason dx9 or 9000p just don’t get on.

Dx9 is dead silent with either the cxa80 and 81
No speaker hum absolutely black silent.

The 9000p as no problem with any other dac.

I called RicherSounds they suggested I take the amp to store for a test.
And also take the dx9.
Now I called the company audio emotion. They said that if the dac works with all other equipment then it’s the amp.

Which I do not believe.
It’s 6 of one and half a dozen of the other.

I have just bought a new xlr cable same prob.

Just hooked up d70 pro to a70 pro to 9000p.
No hum nothing....
Same with all others. Checked connections no hum black silence.

Disconnected all power in the house.
Left a double plug.
Plugged both dx and 9000p ususing same socket.
I removed the earth wire on the dx9
Same problem.

Tonight wi will do the same on the amp.
Obviously it’s dangerous . But I need to know if it’s the ground on amp.

 

[Roland68]

I live in the UK
Power is 240v
3 pin plug .

Just moved a few things around.
So to recap.
Topping causes noise when connecting to
Audiolab 9000p xlr is worse than rca.
The dx9 can connect to cxa80 and cxa60 dead silent no prob.

All other dacs
Adi2 dac fs
Topping d70
Audiolab mdac plus
Even irdac 2
All silent as the dead.

So the dx9 plays fabulously but not with 9000p.
It's go me beat.
Oh the headphones are silent too
No hum lovely silence

Honestly, I'm at my wit's end at this point.

I'd like to test one more thing.
Play the DX9 and Audiolab 9000p through speakers. That should produce the hum.

Now leave everything connected and turned on and test whether the hum is also present in the headphones or not.

 

[terrys999]

Nope dx headphones black silence.
Haha iam beginning to wonder if iam in a twilight zone episode.

Hrm I have a freezer in the garage. But that's on a seperate 30 amp circuit.

Wouldn't be that cus it kicks in every 50 mins for 10 mins.
This hum is changing tone up and down like old uk police care siren 2 tone.

Its doing my head in trying to find a solution