[Glassman]

I've just finished laying out pcb for two pole active Bessel filter at 75kHz.. it's intended use is on friend's Audigy2 ZS card, which even after opamp replacement and power supply caps upgrades sounds still horrible

this is my last attempt to make soundcard out of that crap.. it connects directly to the Audigy DAC's balanced voltage outputs, right before the 10uF DC coupling caps, power supply is +/- 12V from the PCI connector taken from the input of Audigy's +/-5V regulators, LC filter is onboard and it is basicaly how Lynx cards filters their opamp supplies except that I'm using twice the values on Lynx just because I have 2200uF Pana FCs on hand instead of 1000uF used on Lynx.. I suggest using 1000uF + 330uH inductor instead of my 2200uF + 680uH..

don't know if it interests anyone, but here it is:

here you can download the Eagle 4.11 .brd file..

cheers

 

[raif]

Looks cool. In the next couple of months, whenever I get any good at soldering, I will have to give it a go.

 

[Garbz]

hhahah turn the Audigy into a soundcard. That's a laugh. I think u'll find the main source of the mud is the ****ty digital work. All thoes filters, driver adjustments, equaliser, resampler etc which are part of the card.

Let us know how it turns out.

 

[Glassman]

so it's up'n runnin' and it sounds good so far, will test on friends speaker setup and let you guys know.. so far sooo good

 

[rayofsi]

wow, what does one of these cost anyway? =P maybe you should mind as well put together cap upgrade kits =P

 

[drewd]

Hey! No surface mount parts!!!! What's up with that???

-Drew

 

[Glassman]

funny to see you guys expecting me automatically to do it surface mount and kitted

you really made me laugh now

if you want some, we can work something out

but I suggest waiting for the final test results which will be available hopefully tomorrow..

 

[Glassman]

so we've tested it today with a friend on his tubed speaker setup.. tried OP275, OPA2227, even NE5532, but our favorit is OPA2132, no other dual opamps in DIP package on hand, I bet LT1364 and AD826 would sound very good too, maybe even better.. but most importantly - it finaly sounds great! not right up to the quality of modded ESI WT192X and definitely not up to modded Kenwood DP-7090 w/ 8x PCM1702 and 12x OPA627, but it's not far away.. this approach avoids any DC blocking caps in signal way, use higher supply voltage for better operation of the opamps and there's an easy way of rolling the amps