Op Amp Replacement for Asus STX PCI-E Card?

[phileserver39]

Howdy AR.comians,

I am possibly looking to buy different "flavors" of Op-amps for the Asus STX sound card. Here
http://usa.asus.com/product.aspx?P_ID=zCDHPnfR1jymHK2f&templete=2
is the link to the product's specs.

What do op-amps do and how can they/do they effect the sound. Also, where can I shop for op-amps and what would you recommend trying if I had to buy up to five?

Thanks for your time.

Jason

[E-Stat]

What do op-amps do...
The operational amp is the active circuitry that produces the analog audio signal.


...and how can they/do they effect the sound.
Profoundly in every way that any amplification stage may. Early op amps like the LM301 were edgy and hard sounding with a compressed sense of space. Today, they can be pretty decent, but the best one depends upon the circuit involved. Look for top end smoothness and a sense of ease on things like vocals and piano.


Also, where can I shop for op-amps and what would you recommend trying if I had to buy up to five?
You can source them at any number of places ranging from ebay to industrial parts houses like Mouser. Some top models are the LM4562, OPA2134 and OPA627.

rw

[phileserver39]

Thanks so much for your expertise. I will probably buy all three and experiment until my neighbors call the cops.

J

[Dual-500]

Jason, I'm not sure you can swap op amps without other circuit changes.

Op amps I am familiar with are DIP type or Dual Inline Package type. Back in the day, an op amp had a gain of ~100,000 and it was reduced by feedback built into the circuit it was installed in.

I don't have any experience changing or upgrading op amps in audio components.

But, I suggest you look around a little before performing medical experiments on your sound card.

Make sure what you are replacing the OEM chips with components that are direct replacement compatible.

They may be, I don't know for sure - but I do know there is a chance they may not be.

Some good reading:

http://www.stanford.edu/class/ee122/Handouts/2-Op-Amp_Concepts.pdf

http://people.seas.harvard.edu/~jones/es154/pdf/op_amp.pdf

[phileserver39]

Jason, I'm not sure you can swap op amps without other circuit changes.

Op amps I am familiar with are DIP type or Dual Inline Package type. Back in the day, an op amp had a gain of ~100,000 and it was reduced by feedback built into the circuit it was installed in.

I don't have any experience changing or upgrading op amps in audio components.

But, I suggest you look around a little before performing medical experiments on your sound card.

Make sure what you are replacing the OEM chips with components that are direct replacement compatible.

They may be, I don't know for sure - but I do know there is a chance they may not be.

Some good reading:

http://www.stanford.edu/class/ee122/Handouts/2-Op-Amp_Concepts.pdf

http://people.seas.harvard.edu/~jones/es154/pdf/op_amp.pdf

ASUS claims that the opamps in this unit are swappable. However, I am rather like the slow kid with the boom-box on his shoulder on his way to high school when it comes to my trusting what I read on the web.

I will take your advice and figure out what can and can't be done without damage or risk.

Thanks for your response,

J

[Dual-500]

ASUS claims that the opamps in this unit are swappable. However, I am rather like the slow kid with the boom-box on his shoulder on his way to high school when it comes to my trusting what I read on the web.

I will take your advice and figure out what can and can't be done without damage or risk.

Thanks for your response,

J
They probably are readily replaceable. However, there may be some that are not direct replacements.

Look over some of the info on the links. One thing that looks to be is op amp circuits seem to be somewhat standardized - meaning the gain is consistent - meaning they would be interchangeable.

Sonuds like a fun project. Please share the results - good, bad, or otherwise.

:14:

[phileserver39]

They probably are readily replaceable. However, there may be some that are not direct replacements.

Look over some of the info on the links. One thing that looks to be is op amp circuits seem to be somewhat standardized - meaning the gain is consistent - meaning they would be interchangeable.

Sonuds like a fun project. Please share the results - good, bad, or otherwise.

:14:
Will Do Dual! I just ordered, of all things, an actual Asus opamp kit I found through Newegg! Only $9! Whoda Thunk it!?

I am still going to look for the "cream of the crop" (from what I see less than $50 should get me the best pair made). I will report back my findings (stands at attention and salutes).

J

[phileserver39]

Hey all,

I just swapped out the stock opamps with the 2 that were in the ASUS branded upgrade kit that I got from Newegg ($10 with shipping!). First impressions:

1. Treble is much more controlled and upper end is not nearly as "screechy".
2. Imaging seems improved. I have a better sense of depth of field as well as instrument separation.
3. Bass seems tighter and better "behaved" while mids are a bit smoother.

I mean, shiiiiiiiit, where else can $10 have an appreciable effect on the total sound?

There is one opamp that remains to be swapped as the kit only replaces the A and B positions. This is a different opamp all together so I am excited to see what it does to the over all coloration.

Peace out,

Jason

PS- I am running this sound card into:

Audio Experience Symphonies Plus Tube Preamp
NAD 2400 THX 2 Channel Amp
Allison Four speakers (refurbed)

[Dual-500]

Interesting thread - thanks for sharing.

The new ASUS card looks like a real good one. May be time for an upgrade from the Audigy.

[phileserver39]

Interesting thread - thanks for sharing.

The new ASUS card looks like a real good one. May be time for an upgrade from the Audigy.

I highly recommend this card Dual. I have owned an Audigy and an X-fi and the Asus kicks the ever-loving snot out of them. The Asus has shielding which, although certainly not perfect, helps to protect the guts of the card from the noisy computer environment- which, as you know, is normally the big disadvantage of using a computer sound card as a source.

I would put my computer rig (especially after the opamp swap) up against sources costing 10 times as much.

RCA outs! 124db signal to noise ratio! A dedicated headphone amp (which will sufficiently drive any headphone out there)! ASIO Support! It's all good.

Ok, now I sound like an Asus employee! ha ha

I will caution you, though, that if you want to record through this card through the LINE IN to keep looking. Horrible latency!

Best,

Jason