Change the onboard op-amp and coupling caps and make your A1A2 sound much better

Timme · Jun 12, 2004, 10:20 AM

the a1a2 owns perfect DSP & DACs, but the op-amp totally spoiled the performance.

the ST4558 & JRC4556 onboard is of the cheapest & worst op-amps, < $0.1 per each i think.

this also cause a1a2 cards sounds worse than cards like DMX6fire & Revolution 7.1. i think one main reason is that they r using NE5532 op-amps

i change the 4558 opamp to OPA2312u, also the coupling caps r needed to be changed after installing a high-performance op-amp. After trying ELNA, Solen i finally chose Rifa 420.

btw:i'm studing information engineering in university

http://timme.8u8.com/a1_3.jpg

Daniel Drummond · Jun 12, 2004, 11:05 AM

Sounds like a nice idea. Have you done any audio tests comparing sound before and after the change to see if there were measurable improvements?

Doug W · Jun 13, 2004, 05:53 PM

So did you you solder in all those red caps in the JPEG in addition to those op amps?

Maybe you could post a parts list with some more details on exactly where to make the connections along with ideas about what type of solder and what heat to work with.

Just a thought...

Doomsayer · Jun 13, 2004, 06:56 PM

Hey, why not change DACs?

Use some new expensive capacitors, op-amps, install cooling, then wrap your card in foil to shield it from interference and enjoy a true audiophile-component-stuffed card, which, oh dear, still resamples to 48k

But I sure would like to see some test results on the modified card.

**dj_stick** · Jun 13, 2004, 07:15 PM

http://audio.rightmark.org for audio analyis tests… also compare results with the live & audigy they have listed there

TravelRec. · Jun 14, 2004, 12:24 AM

Hi!

I don´t think you´ll get sooo much better sound only by changing the op-amp and some capacitors (maybe I´m wrong), ´cause the op-amp in the line path is working only with an amplification of 1 and so the op-amp will not add significant noise (I don´t speak about the mic in!) and will not have so much influence on the incoming signal. And for frequencies between 20 and 20.000 Hz nearly every capacitor works fine for coupling (except some cheap electrolyte-types) - I don´t want do get my card off the computer and solder there around for say 1 db noise reduction and some modulation decreasing or so. Sorry for my ignorance but I don´t think you can make it all better only on the analog side of the card...

Greetings!

TravelRec.

**dj_stick** · Jun 14, 2004, 01:08 AM

i want to see the RMAA results for this

Tiger M · Jun 14, 2004, 08:25 AM

>>wrap your card in foil to shield it from interference

Does this make the overall performance better?

Doomsayer · Jun 14, 2004, 11:17 AM

This trick was described on one russian site (don't remember where, sorry), they claimed an increase in signal/noise ratio on an SBLive of like 5db. I went for it on my Live 5.1, but I didn't carry out any benchmarking. I found no audible difference, however. Just remember that foil should be isolated from the card itself with something non-conductive and it should be grounded as well.

**dj_stick** · Jun 14, 2004, 03:00 PM

it should prevent emi to an extent, but there will still be a fair bit picked up through the pci connections

swimtech · Jun 14, 2004, 04:29 PM

Mods like this are frequent (op-amp) throughout the history of audio gear over the last 15-20 years or so. I had a Magnavox CD player that would have benefitted from an op-amp replacement according to many - and there are audio equipment design engineers who swear it helps - I tend to believe them...

However, don't forget to color the foil you enclose the card in with green magic marker...

**dj_stick** · Jun 14, 2004, 06:15 PM

Quote:

Originally posted by swimtech
However, don't forget to color the foil you enclose the card in with green magic marker...

that is a touch of sarcasm i guess lol

Timme · Jun 15, 2004, 12:03 AM

http://timme.8u8.com/jensen.jpg

http://timme.8u8.com/card_j.jpg

http://timme.8u8.com/tweeter_j.jpg

http://timme.8u8.com/amplifier_j.jpg

newer changes

wait for my RMAA result...

Tiger M · Jun 15, 2004, 01:36 AM

Quote:

Originally posted by swimtech
However, don't forget to color the foil you enclose the card in with green magic marker...

I'll send the foil to you, so you can paint it yourself. That way I'll be shure that this is done by a magic marker proffesional.

swimtech · Jun 15, 2004, 07:53 AM

Quote:

Originally posted by dj_stick
that is a touch of sarcasm i guess lol

Yes, just being funny, no disrespect intended.

swimtech · Jun 15, 2004, 07:54 AM

Quote:

Originally posted by Tiger M
I'll send the foil to you, so you can paint it yourself. That way I'll be shure that this is done by a magic marker proffesional.

Touche', you got me, good one!

TravelRec. · Jun 17, 2004, 12:58 PM

Quote:

Originally posted by Timme
http://timme.8u8.com/jensen.jpg

http://timme.8u8.com/card_j.jpg

http://timme.8u8.com/tweeter_j.jpg

http://timme.8u8.com/amplifier_j.jpg

newer changes

wait for my RMAA result...

O k a y . . . what is the power of your solder iron - 200 watts ???

Whoa, please be careful and don´t burn your card!!!

BTW: I think the 50 hz noise will be bigger in the RMAA with such big capacitors around the card.

Greetings!

TravelRec.