Tuesday, January 10th 2012

ASUS ROG Phoebus Sound Card Pictured, Driven by New CMI Oxygen Express Chip

ASUS displayed its latest sound card, the Republic of Gamers (ROG) Phoebus. This card is designed for multichannel gaming audio. While it might not pack any fancy DSP that doesn't already exist, its AMP circuitry is so designed to give the best positional audio that could come handy with competitive online gaming. With this card, ASUS also brought to the fore C-Media's latest audio chipset, the CMI 8788DH Oxygen Express, which packs native PCI Express support. All PCI Express sound cards launched by ASUS so far feature OxygenHD and ASUS-rebadged AV-100 chipsets, that use legacy PCI, and hence depend on PCIe-to-PCI bridge chips by PLX to function on PCI Express.

The primary DAC for headphone/front-out channel of the ROG Phoebus is TI-BB PCM1792A, with stellar signal-noise ratio (SNR) of 127 dBA. Other main channels are handled by Cirrus Logic, probably the CS5381, with SNR of 120 dBA. There's also a tertiary Realtek ALC889 (110 dBA) CODEC that probably handles an independent set of audio channels, or handles the digital outputs, since it's licensed with a few Dolby technologies. On the AMP side, we spy bleeding-edge OPAMPs, a Texas Instruments 6120A2(?) AMP chip (for the headphones channel), etc.

Many parts of the card are electrically isolated from the PCI Express slot, to prevent interference from the ground layer of the motherboard. So these parts rely on power drawn from a 6-pin PCIe power connector, conditioned by a tiny VRM. Only the power-conditioning parts of the card use solid-state capacitors, the AMP and audio parts use audiophile-grade electrolytic capacitors since by design they are better for analogue circuits. The whole card is topped off with a groovy-looking EMI shield. Expect this card to be costly.Source: VR-Zone
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25 Comments on ASUS ROG Phoebus Sound Card Pictured, Driven by New CMI Oxygen Express Chip

#1
Scatler
I already fear the day when audio cards will require dual 8 pin power. *shiver*
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#2
btarunr
Editor & Senior Moderator
by: Scatler
I already fear the day when audio cards will require dual 8 pin power. *shiver*
This card should barely draw 10W. If you read the article, the idea behind that power connector was electrical isolation from the slot.

Why no Molex? Because it's an old, ugly connector in its dusk.
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#3
Live OR Die
I've been waiting for this card :rockout:
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#4
RejZoR
by: btarunr
This card should barely draw 10W. If you read the article, the idea behind that power connector was electrical isolation from the slot.

Why no Molex? Because it's an old, ugly connector in its dusk.
ASUS Xonar Essence STX was using 4 pin molex for power supply in addition to PCIe. Also power draw was apparently pretty high because i had power stability issues when it was plugged in on a 550W PSU with higher end components. It was aooarently on the edge already and the soundcard tipped it over...
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#5
FreedomEclipse
~Technological Technocrat~
I wonder if this is worth getting over the Xonar STX....

though, I really do wish Asus would spend more time on their Audio drivers. They only really release a new driver once or twice a year and it doesnt matter if their new drivers are bugged or not they just make you wait until the next release :(

luckily, modded drivers are available and they are leagues ahead of Asus's the change log is like a 50 page essay on Astro Physics compared to Asus's own changes/updates.
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#6
robal
Electrolytic caps ?!
I know it's not a power-circuit, but still...
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#7
arterius2
by: robal
Electrolytic caps ?!
I know it's not a power-circuit, but still...
wrong, those are high quality audio-grade electrolyte caps, the ones used on this card I believe are called 'muse-gold'

you obviously do not know a whole lot about analogue circuits, many professional and top end audio equipments use electrolyte caps because they tend to sound more 'musical' (warm or tube-like) to the solid state caps.
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#8
btarunr
Editor & Senior Moderator
by: robal
Electrolytic caps ?!
I know it's not a power-circuit, but still...
Solid state caps suck with analogue circuits (audio quality is bad, sounds too shrill/synthetic). The electrolytic caps on this card cost 5~10x the solid caps found on motherboards. They needn't be as durable, since they're not handling large currents.

Besides VRM areas, a PC motherboard doesn't really need solid caps in other parts. The vendors put them anyway, for PR reasons.

by: RejZoR
ASUS Xonar Essence STX was using 4 pin molex for power supply in addition to PCIe. Also power draw was apparently pretty high because i had power stability issues when it was plugged in on a 550W PSU with higher end components. It was aooarently on the edge already and the soundcard tipped it over...
Maybe because the rest of the rig is already pushing the PSU far, and the sound card is just putting it at its breaking point. There's no way a sound card draws over a dozen Watts. There's nothing on it that needs that much power.
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#9
Cold Storm
Battosai
It looks cool.. It sounds like something good.. But, if I can't go and swap my opamps easily... It's not for me...
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#10
Sihastru
by: robal
Electrolytic caps ?!
I know it's not a power-circuit, but still...
There are some solid caps that can be considered "audio grade" but they don't look any different from the usual solid caps. There are more electrolytic caps that made the "audiophile" grade then there are solid ones (and there's a war going on there).

Also gold painted electrolytic caps are easylier to explain for the marketing department. There are some green/blue/magenta ones that are much better.

Even if it makes no difference whatsoever.
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#11
FreedomEclipse
~Technological Technocrat~
people believe too much that anything made of gold (or looks like gold) is pure win.
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#12
RejZoR
by: btarunr
Solid state caps suck with analogue circuits (audio quality is bad, sounds too shrill/synthetic). The electrolytic caps on this card cost 5~10x the solid caps found on motherboards. They needn't be as durable, since they're not handling large currents.

Besides VRM areas, a PC motherboard doesn't really need solid caps in other parts. The vendors put them anyway, for PR reasons.



Maybe because the rest of the rig is already pushing the PSU far, and the sound card is just putting it at its breaking point. There's no way a sound card draws over a dozen Watts. There's nothing on it that needs that much power.
I doubt that it was in the ~5W difference zone. It had to be more.
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#13
claylomax
by: FreedomEclipse
I wonder if this is worth getting over the Xonar STX....

though, I really do wish Asus would spend more time on their Audio drivers. They only really release a new driver once or twice a year and it doesnt matter if their new drivers are bugged or not they just make you wait until the next release :(

luckily, modded drivers are available and they are leagues ahead of Asus's the change log is like a 50 page essay on Astro Physics compared to Asus's own changes/updates.
To get Asus modded drivers, check FreedomEclipse signature. :D
Posted on Reply
#14
tigger
I'm the only one
Very nice, really good SNR on the front outputs, but were is the FP connection gone :(
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#18
repman244
by: RejZoR
ASUS Xonar Essence STX was using 4 pin molex for power supply in addition to PCIe. Also power draw was apparently pretty high because i had power stability issues when it was plugged in on a 550W PSU with higher end components. It was aooarently on the edge already and the soundcard tipped it over...
The whole point of the extra molex connector was to avoid the dirty power from the motherboard, PCI-e is there only for data.
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#19
LAN_deRf_HA
Did Asus ever fix that headphone/eardrum damaging super screech? I know it's rare but the possibility of ear damage is significant enough to warrant never recommending their soundcards.
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#20
Horrux
by: Cold Storm
It looks cool.. It sounds like something good.. But, if I can't go and swap my opamps easily... It's not for me...
My Auzentech Preludes have that feature I believe. I haven't upgraded anything on any of them though. Should I?
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#21
TheLostSwede
by: tigger
Very nice, really good SNR on the front outputs, but were is the FP connection gone :(
That's what the special headphone/mic extension is for which also add noise cancelling microphones...
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#22
Static~Charge
by: btarunr
Why no Molex? Because it's an old, ugly connector in its dusk.
Assuming that you have a 6-pin PCIe power connector to spare, after your video cards are installed. Unused Molex connectors are a lot easier to come by.
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#23
jalex3
How is Asus software? I'm still feeling burned by my old Creative problems.
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#25
MadMan007
At least they are focusing on the only part of a soundcard that matters any more: the analog output.

I, however, will still stick with an external DAC hooked up to onboard audio. Since I don't care about 5.1 or 7.1 sound that is the best solution for me, and you can get very good quality DACs for the price of high-end soundcards. If you really want surround a receiver and passive speakers, or a sound card such as this and active/powered speakers, are the way to go.
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