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Dx9 Hum
- Thread starter terrys999
- Start date
- Thread Starter
- #23
Ok
Now just used power cable with earth disconnected.
Dx preamp to 9000p hum still present.
Lastnight I connect dx9 dac mode to a70 pro.
Then a70 to 9000p.
Frigging noise still there
There's something in the dx signal that's doing this.
Now just used power cable with earth disconnected.
Dx preamp to 9000p hum still present.
Lastnight I connect dx9 dac mode to a70 pro.
Then a70 to 9000p.
Frigging noise still there
There's something in the dx signal that's doing this.
- Thread Starter
- #26
There’s no ground lift on dx9 or 9000p.No hum from amp or speakers when nothing connected.
Playing music now with adi 2 with a70 pro to 7000p no noise.
Just tried d70pro with a70 pro no noise in speakers when paused.
9000p dead silent.
Playing music now with adi 2 with a70 pro to 7000p no noise.
Just tried d70pro with a70 pro no noise in speakers when paused.
9000p dead silent.
- Thread Starter
- #28
Wondering if the dx9 power blocks are no compatible with 9000p.
If I send the topping back. It will run fine for them.
They would need to test with 9000p.
Which they wouldn’t.
I would have to replace both units. And I ain’t doing that.
If I send the topping back. It will run fine for them.
They would need to test with 9000p.
Which they wouldn’t.
I would have to replace both units. And I ain’t doing that.
BeeKay
Major Contributor
Sorry if I missed it but have you tried to power the set up in a different house?
The topping dx9 is the dx9 you are talking about because if it is it has a ground pin on the power inlet. Try using the power cord with no ground pin on it and see what you get then.
- Thread Starter
- #31
No I haven’t hrmm most of my friends live a long way from me, and they aren’t hifi guys.
Plus my partner developed early onset Alzheimer’s so I need to be here.
It’s a bummer, but iam her carer, she cant walk.
I see what you mean though, dirty power supply???????.
There’s something in the other amps that is blocking that noise.
Plus my partner developed early onset Alzheimer’s so I need to be here.
It’s a bummer, but iam her carer, she cant walk.
I see what you mean though, dirty power supply???????.
There’s something in the other amps that is blocking that noise.
- Thread Starter
- #32
Tried that half hour ago.
Removed Earth. On both units. Same noise.
Noise sounds like it’s shifting tone hum that goes up down slowly
- Thread Starter
- #34
- Thread Starter
- #35
Roland68
Major Contributor
A power conditioner would be utter nonsense and a complete waste of money, especially with this problem.
The only thing that would make sense to try would be a ground isolation filter/galvanic isolation filter to eliminate ground loops for RCA or XLR connectors.
This looks like a classic ground loop. It would be really interesting if a specialist workshop/professional could take a look and measure what's causing it.
KenA
Member
You could consider an Audio Isolation Transformer in either the XLR or RCA line. Known as a ‘hum killer’. Someone here may offer their expertise if this could be a solution?
(Which may be the same as Roland68 suggested).
(Which may be the same as Roland68 suggested).
- Thread Starter
- #39
Wow .you think it might work?
I bought new xlr cable the other day.
Stripped all connections to the setup.
Nope didn't work.
Can you recommend which isolation transformer?
Definitely something from xlr and rca.
I used to have buzz/transformer hum that would come and go , sometimes go away completely. But never audible from the speakers.
Different combinations of SMSL Dac , Cambridge CXN v2 , Cambridge CXA81 and finally Yamaha AS2200. And I had a Hifiman EF400 that hummed with nothing connected.
So what did I do ?
- Mains filter for my Fridge.
- DC Blocker+ for the Amp.
- Dynavox Powerstrip with emi/rfi Filtering for my TV/Playstation/Mac mini stuff
- Monosaudio shielded powercables
- shielded cat6 cables for my network stuff
Sold my SMSL gear , upgraded the CXA81 to the AS2200… and I still had that transformer buzz occasionally, very quietly..
Got myself a Furman AC210 mains conditioner and dead silent amplifier.
I’ve even added a Cayin HA-2A tube headphone amp into the setup and I’m running a turntable.
Zero issues
so I would definitely recommend trying a Furman power conditioner and a DC Blocker.
And don’t connect XLR and RCA at the same time on the topping.. this could also cause a groundloop.
(I would definitely get rid of everything topping/smsl/aiyima/fosi stuff)
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