Moding soundcards

[Shadowmeph]

I read the review on the ASUS Xonar DX 7.1 PCI-E and was impressed enough to buy one now I am wondering what Mods I can do to this card also a how to mod this card would be helpful, I just want to do this because it can be done also to see if I can do this and if it works well I win all the way around if not well at least I tried lol

[enaberif]

Originally Posted by Shadowmeph

I read the review on the ASUS Xonar DX 7.1 PCI-E and was impressed enough to buy one now I am wondering what Mods I can do to this card also a how to mod this card would be helpful, I just want to do this because it can be done also to see if I can do this and if it works well I win all the way around if not well at least I tried lol

Better off to buy a Xplosion or Prelude as mods are easier.

[SugarJ]

Originally Posted by enaberif

Better off to buy a Xplosion or Prelude as mods are easier.

@enaberif: That's not what he asked. He's already bought the card.

@shadowmeph: I suggest you chat to turtletrax, I think he's got experience modding sound cards. He may be able to point you in the right direction.

[Shadowmeph]

Originally Posted by SugarJ

@enaberif: That's not what he asked. He's already bought the card.

@shadowmeph: I suggest you chat to turtletrax, I think he's got experience modding sound cards. He may be able to point you in the right direction.

Thanks for the info

[biff]

I'm no expert in audio cards but what kind of mods were you hoping for? AFAIK the bottle neck in sound quality for digital sources is the DACs which I don't think there is anything you can do about it. I guess poor construction techniques could have ill effect too like bad grounding practices and shielding but again, nothing you can do about it.

I'd love to hear what can be done though since it would be nice to be able to get a cheaper card and mod it to something better, certainly something I'd be interested in.

[Robscix]

The DAC's on the Xonar DX aren't bad quality at all. The weak point of this particular card...is the opamps. You could use a better models. Surface mount opamps aren't easy to replace. There are many more advanced mods for soundcards but this is the place to start, the output opamps. I can suggest a few but the one that would give you great gains for the price would be the LM4562's.

[CanadaRox]

I'm not an expert on this or anything, but from the bit that I've seen, people will usually replace the opamps first, and then change the caps to ones that give a cleaner (more stable) voltage. Your best bet for learning how to do this would probably be at an audiophile/computer forum.

[biff]

Originally Posted by Robscix

The DAC's on the Xonar DX aren't bad quality at all. The weak point of this particular card...is the opamps. You could use a better models. Surface mount opamps aren't easy to replace. There are many more advanced mods for soundcards but this is the place to start, the output opamps. I can suggest a few but the one that would give you great gains for the price would be the LM4562's.

It's been a few years since I've poked my head in an audio electronics text so my info is certainly outdated. Also I realize it may look like I'm being a smart-ass but I'm really not trying to be, I'd appreciate being corrected where I'm wrong. Oh, and I have the memory of a goldfish so consider that too.

As I recall the human hearing threshold for distortion was 0.1% for even order harmonics and 0.03% for odd order harmonics. Now back then a few of the prefered opamps were the TL081, NE5532, LM833, and an OPA27 or 37, IIRC to name a few (and I think they were long in the tooth back then). All of those were 0.002% distortion or less and cost about a buck or so. I would have thought there'd be better for less $$$ these days. I quickly checked the datasheets for the LM4562 and yeah modern opamps are WAY better. However even those opamps are only $4 and change, are soundcard manufacturers cheaping out that badly?

I can kinda see about the caps. Polypropylene and ploycarbonate caps were the best but they were much more expensive and bigger than their ceramic counterparts.

I guess a dollar here and there adds up when trying to maximize profit on a product.

[vinister]

water-cool it ;)

[biff]

Originally Posted by CanadaRox

Ithen change the caps to ones that give a cleaner (more stable) voltage.

just to let you know.... the caps that would be replaced are in the signal path so "a more stable voltage" doesn't really apply as audio is AC. Stable voltage refers to DC and PSRR's have been well below hearing thresholds for decades for opamps specialized for audio use, even 70db is worst case.