[hmscott]

I did. That's the first thing I tried.

You tried a different power source? You moved to a different room, or a different house? What is it that you tried?

There is noise that comes in on the power line, and noise that is simply picked up out of the air - high power lines - underground or over head - and if you still have noise when changing to a known clean power source then it's in the air in your area - near a powerful RF transmitter? - Cellular tower? Commercial communications location? Police, fire, or amateur radio operator?

The source of the induced noise can come from lots of different environmental emitters.

And, it can affect inexpensive and very expensive hardware. Even Krell stacks fall victim to environmental noise.

That's why XLR balanced feeds were developed for their noise rejection.

What is the input to your source, USB? If so, can you disconnect the USB and try optical to see if the noise remains? If it does, then it's probably the power source bringing it to your system. If it goes away, then it's coming from your computer. You can consider getting an ifi iGalvanic or something, that's worked pretty well for me to remove any kind of USB issue. It's not something that's specific to A90, any source device without properly isolated USB, connected over RCA, would suffer from (some degree of) this and that feature is usually only found on higher end DACs.

As @ra990 said the USB cable can also bring problems. Use a data only cable for one, you don't have the power live across that link so you don't need those power wires physically bridging the connection.

Users shouldn't have to go to great lengths to get something to work. It should work right out of the box on a typical desktop setup. If my $100 Schiit stack works perfectly fine, so should this. I also have zero problems with my Focal Arche.

I've seen ground loops in Krells sitting right next to Meridian's, and visa versa. It's all what's in that loop that contributes.

Are you saying that you can unplug the Focal Arche and swap the A90 in it's place - same power cable same headphone cable and the A90 has noise and the Arche doesn't?

 

[hmscott]

Anyways, I think I've covered this issue enough. I'm not trying to discount the product, as I genuinely like Topping products. Best bang for the buck so to speak. Hope I see some changes with the replacement unit. Thanks for all the tips and suggestions. But like I said before, users shouldn't have to go to great lengths to get something to work properly.

And, I'm trying to help you debug the noise problem you are having on RCA connections.

If you are ok on XLR's then I'd say you are good if you are happy with the A90's sound.

I've heard that said by IDK how many people in the middle of debugging this kind of environmental noise, why can't the engineers solve this? I say they have, get a unit with XLR connections and you'll be good to go.

At least this time with the A90 you have the opportunity to make that change to XLR cables.

 

[KPzypher]

You tried a different power source? You moved to a different room, or a different house? What is it that you tried?

moved to dedicated listening room, same house.

There is noise that comes in on the power line, and noise that is simply picked up out of the air - high power lines - underground or over head - and if you still have noise when changing to a known clean power source then it's in the air in your area - near a powerful RF transmitter? - Cellular tower? Commercial communications location? Police, fire, or amateur radio operator?

I barely even get a cell signal from my house.

The source of the induced noise can come from lots of different environmental emitters.

And, it can affect inexpensive and very expensive hardware. Even Krell stacks fall victim to environmental noise.

That's why XLR balanced feeds were developed for their noise rejection.

I've seen ground loops in Krells sitting right next to Meridian's, and visa versa. It's all what's in that loop that contributes.

This isn't my first desktop setup. I've never had noise issue at this level with any of my previous gears.

Are you saying that you can unplug the Focal Arche and swap the A90 in it's place - same power cable same headphone cable and the A90 has noise and the Arche doesn't?

Yes. Both the Focal Arche and the Schiit Modi/Hersy stack work perfectly noise free in that same location with same cables.

 

[KPzypher]

And, I'm trying to help you debug the noise problem you are having on RCA connections.

If you are ok on XLR's then I'd say you are good if you are happy with the A90's sound.

I've heard that said by IDK how many people in the middle of debugging this kind of environmental noise, why can't the engineers solve this? I say they have, get a unit with XLR connections and you'll be good to go.

At least this time with the A90 you have the opportunity to make that change to XLR cables.

I know and thanks for your help. And i'm aware of my options. I just wanted headfiers to be aware of potential limitations with the A90.

 

[hmscott]

moved to dedicated listening room, same house.

I barely even get a cell signal from my house.

This isn't my first desktop setup. I've never had noise issue at this level with any of my previous gears.

Yes. Both the Focal Arche and the Schiit Modi/Hersy stack work perfectly noise free in that same location with same cables.

All supporting it's the A90 with self-induced noise in the RCA section. Yet so many others don't have that problem. Logically you'd then think it was that particular unit.

But the A90 using an XLR connection you have no noise, right? Not even a little tiny bit on your most sensitive IEM?

So enjoy the XLR connection and be happy, just like all of those running RCA in their environments free of noise...

Or, follow the rabbit hole...return this A90 for another one and hope it's that particular unit with a noisy capacitor or inductor - or some other noise inducing part.

Sorry about this, it's frustrating I know. I've taken equipment from people that have such noise problems over to a lab bench and it's quiet as can be. But, in their environment it's noisy as heck. And, most often they have no XLR option. Then they've got to debug the noise problem, which can take weeks - or sometimes people have been known to move, like me from those high tension wire towers.

 

[ra990]

I know and thanks for your help. And i'm aware of my options. I just wanted headfiers to be aware of potential limitations with the A90.

Could also genuinely be a problem with some units, while others are fine. Some of those that have asked for exchanges will hopefully reply back with their experiences.

 

[hmscott]

Could also genuinely be a problem with some units, while others are fine. Some of those that have asked for exchanges will hopefully reply back with their experiences.

It's a long way back to China. That's why I was trying to suggest various solutions. For the cost of shipping back to China you could buy a set of XLR Cables

If someone has this problem try taking it to a trusted audio shop with a grounded bench, clean power, and experience troubleshooting such interference problems and see if they can help.

 

[the machine]

There have been reports of noise on RCA interconnects between the A90 / D90 or between the A90 and powered speakers. When they move to XLR interconnects the noise goes away.

Historically I've experienced the same issues with other hardware, moving to XLR's to avoid noise, so it's no surprise some are experiencing it with the A90 /D90.

If I had this problem - I would move to XLR's and then the first chance I had I'd set up the D90 / A90 on RCA in another physical location with different power and a low noise different environment, hopefully one away from power lines and noise generating equipment.

There are power isolators - ground breakers or isolation transformers I would use while stuck on RCA's to see if that cut the noise, and move any appliances or EMF emitters and cables carrying video or RF away from the A90 / D90 - basically debug the interference as if it's from an external source causing the "noise". Most of the time - 99%? - I've debugged such situations to an external generator of noise - the unit itself wasn't responsible for the interference.

I've ordered audiophile shielded RCA cables for interconnecting the D90 / A90 to see if I experience the same noise, I already have XLR's for between the D90 / A90, and I'll see if I can get some shielded cables and powered speakers as well to test.

Sorry to hear some are having this problem...noise problems like this are annoying.

Good to know. I guess at some point when I have some time I'll dig through my bag'o'wires and find some RCA's to see if there is any issue. I'm assuming if so, there should be some way to get this fixed from Topping. But, I'd hate to have to wait to send it back to China, wait for the repair, then wait for it to come back to the US. Initial shipping was pretty quick though.

 

[Reader]

Just FYI, RCA works fine for me. Zero noise at any gain any volume.

 

[wallaby1170]

I’m not experiencing any noise from the RCA either. Given the technical specs I thought the A90 would sound almost identical to the THX 789. Based on a very limited amount of time comparing the A90 and the THX 789, the A90 appears to have a wider soundstage and a slightly warmer sound. At times the THX 789 sounds kind of plasticy if that makes any sense.

 

[Ra97oR]

Been using the A90 with my Hugo 2 with RCA and have zero issue with noise, I am suprised how quiet the amp actually is.

 

[the machine]

I’m not experiencing any noise from the RCA either. Given the technical specs I thought the A90 would sound almost identical to the THX 789. Based on a very limited amount of time comparing the A90 and the THX 789, the A90 appears to have a wider soundstage and a slightly warmer sound. At times the THX 789 sounds kind of plasticy if that makes any sense.

This was exactly my feelings as well. 789 was so neutral, A90 brought out just a touch more warmth and bass depth to my focal clears. Could be placebo, or the D90 vs D70 DAC's as well as I didn't try the D90 on the 789. I'm very satisfied with A90 D90 stack

 

[NA Blur]

If you're hearing random high-pitched sounds it's interference 99% of the time. This can be because the unit / RCA cables are too close to a cable modem, cell phone, or other device. I had the same issue using RCA cables on a Topping D50s. It was 2" away from my cable modem. Moved it a few feet and now the unit is silent.

 

[NA Blur]

Actually, now that I think of it. It makes more sense that the HP circuit is not properly grounded to the chassis ground.

 

[Swisstoni]

Been using the A90 with my Hugo 2 with RCA and have zero issue with noise, I am suprised how quiet the amp actually is.

Hi
Just joined and thought I'd ask about your experience with the topping a90 over the normal headphone out on the hugo 2. Just bought a pair of empyrean's and wanted to know if you find the a90 pairing with the hugo 2 to a good upgrade ?