Strange issue playing AOE II DE


2009-06-09 4:17 pm
Gentlemen, I own a PC (image 1), running Windows10, whose soundcard (ASUS XONAR AE) is connected to an ACA ClassA amplifier
with DIYed-speakers being connected to it (image 2).
Playing CDs or ripped music files (mainly .flac and .mp3) or listening to YouTube (very seldom): the sound is really beautiful.

Last week I have bought a strategy game from the Microsoft game store: "Age of Empires II - Definitive Edition", installed it
(no problem - but I had to download about 19GB (!) of data before) and started the game.
I listened to the introductorily music, then started the learning lesson) and: I did not hear anything else but loud hum, noise, …
The same thing happens, when I start any campaign.

I connected the ACA to the Mainboard Realtek 892 music chip, to an external USB soundcard (image 3 - I have installed current drivers),
I even did a new and "clean" (nothing but current drivers and the game) Windows10 install,but the "noise-problem" persisted.
I logged on to the Microsoft AOE II Forum - I seem to be the only one to have this problem.

I then bought a new HAMA Sonic 500 PC-soundsystem (costs: 33€, image 4) - and: my "sound problem" is gone.
I do not hear the least noice on the HAMA sound system.
So currently I can (have to) choose between 2 sound-Sources on my PC: "ASUS XONAR AE connected to my ACA" and
"Mainboard Realtek 892 connected to the HAMA Sonic 500".

I cannot see, which codec Microsoft is using to generate speech and ….
Microsoft is using a "new data Management System" to store a game that has nothing to do with FAT32, NTFS, …
I see that my disk is occupied with 19GB of data, I even see 3 folders: but the 3 folders are all empty.

I suppose that the HAMA Sonic 500 has some kind of filter (highpass, bandpass, ..?) in front that the ACA does not have.

Has anyone of you an idea of what is going on?

Best regards - Rudi_Ratlos


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This one really smells like a ground loop. When the graphics card gets going, all hell breaks loose. Modern, efficient power supplies also have a habit of passing a lot more high-frequency components to the mains.

The ACA uses a SMPS brick with a 3-pin IEC input. Please measure resistance between DC output jack ground and IEC socket center pin. I would not be surprised to see a direct connection.

The Hama soundbar presumably is floating (IEC Class II device). So would be a majority of traditional hi-fi amplifiers.

A galvanic line isolator (ground loop isolator) might be the easiest solution, though many of the cheap ones aren't necessarily all that great. Alternatively, consider modifying the ACA with isolated RCA jacks and input transformers, e.g. Vigortronix VTX-102-007 (1+1 : 1+1, 2.4 kOhm nominal in & out) or VTX-101-007 + VTX-102-000.
Connecting PC output to class I amp with unbalanced line almost always generates ugly noise. The noise gets created by high currents running through ground traces of the PC motherboard between onboard connection of the 0V line of the soundcard/PCI-e/USB port and the 0V terminal of the PSU to which the PE wire is connected. Every motherboard behaves differently.

I would not get a class I amp with unbalanced-only input if I were planning to use PC (or even NTB) somewhere in the chain. Since you already have one, you will have to break the loop somehow.


2009-06-09 4:17 pm
Gentlemen, thank you for your advices.

What I did in the meantime: I have driven to a friend of mine and leaned his "AOE III" CDs (dating from 2003).
After Installation I had access to hundreds of .mp3 files.
I played a couple of them: no problem, no hum.
But when I played the game (source was: ASUS XONAR AE soundcard connected to my ACA / DIY speakers): a "terrible" whistling noise, …

And, once more: no noise, when I changed to the HAMA Sonic TFT 500 PC Speaker - being connected to the lineout of the on-board Realtek 892 soundchip.

I compare the HAMA and the ACA: both amplifiers use a wall power supply.
The "original" ACA (as is connected to my PC) uses a Dell laptop power supply, rated at 19,5 VDC / 6.7A.
The HAMA uses a wall power supply, rated at 15VDC / 1A.

Both amplifiers reproduce music files (with codec: .mp3, .wav, .flac - player is: FOOBAR2000) without any problem / noise.
And, believe me: listening to the XONAR/ACA/DIY-Speaker - ensemble reminds you of sitting in the "Hamburger Elbphilharmonie" (see attached image).

When I change to "Age of Empires" (either the AOEIII - 2003-publication or the current AOEII - Definitive Edition"): the HAMA does its job: simply and unpertubed
- whereas the ACA generates lots of noise.

I do not think that I am having hardware problem.
If I had: how can you explain the excellent sound while playing music by FOOBAR2000?

What I suppose is a "software" issue (I am reading "behind the lines" of the post of sgrossklass).
What does it mean when DirectX comes into play? Both AOE games use this feature!
Is there something like "DirectSound, …", a feature that the HAMA supports and the ACA does not, … I Need to find out!

I will check sgrossklass" post in more Detail.

Best regards - Rudi


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I compare the HAMA and the ACA: both amplifiers use a wall power supply.
The "original" ACA (as is connected to my PC) uses a Dell laptop power supply, rated at 19,5 VDC / 6.7A.

Class I adapter - the 0V is very likely connected to the PE wire.

The HAMA uses a wall power supply, rated at 15VDC / 1A.

Class II adapter, no PE wire, galvanically isolated from the mains, only Y-class EMI decoupling capacitors.

My 2 cents (and many confirmed cases) the ground trace from your graphics card PCI-e slot (and/or CPU socket) is (partially) shared with ground trace from other PCI-e slots/USB ports/integrated Realtec codec. When the graphics card (and/or CPU) load increases (game started), the noise voltage created by the large currents through the shared ground traces causes currents in your 0V return wire of the single-ended connection to the class I amp. Again, it is a very common problem. No software issue involved.

Solutions have been already given, all are about breaking the ground loop you experience:

- line-level isolation transformer
- class II amp
- balanced amp input
- galvanically-isolated digital output (optical, proper coax with isolation transformer)
- to some extent adding resistors in the 0V return line to limit the ground-loop currents - point 3 ABOUT GROUND LOOPS


2009-06-09 4:17 pm
Thank you, phofman, for pointing me to this article:


The accompanying image shows possible sources and resolutions for existing ground-loops.

I tried reason c) - resistive shield - but his did not remedy the situation at all.
I then tried reason e) - transformer - and I do not have any hum anymore, neither while listening to the PCs music nor while playing AOE.

Thank you very much for your advices - Rudi_Ratlos

P.S.:No Ground-loop exists using the HAMA Sonic 500, since the HAMA PC speaker is a Electric Class II device and ist PSU is not connected to Protective Earth!
So: a Ground-loop is not possible using the HAMA.


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I am glad you have resolved the issue.

The moral of the story is simple - do not buy/build a class I amp without balanced inputs. Commercial manufacturers selling class I amps with only unbalanced inputs are irresponsible towards their customers. Customers do not understand the traps of the combination and regularly complain about their internal/external PC soundcards, even though these are usually perfectly OK.

Notice that AVRs are almost always class II, just as regular stereo amps used to be class II, even quite powerful ones (with large standard transformers, properly designed and tested for class II isolation requirements). At home I have Kenwood KA7010 from 1990 connected to PCI soundcard of my old HTPC with standard ATX PSU - absolutely silent even at maximum volume, thanks to properly isolated dual transformers in the 15kg beast. But costs of such transformers today... Making a high-power SMPS adhering to class II is quite expensive, unlike a low-cost class I version which many producers use.

Offtopic: Notice that typically overpriced gear for "audiophiles" is class I (cheaper to make) and has unbalanced inputs only (again cheaper to make).