[Hookem]

"Use two OPA2604's and the AD8022 at the front. You'll need an adapter to insert it into the socket."

+1

 

[FallenAngel]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Since the AK4396 is a voltage out DAC, has anybody tried to bypass the opamps all together? Very interested as I just bought this card and since I have some very strong amps, I don't really want any extra line-driving opamps. I'm also going to be looking at the coupling caps on this thing, perhaps I can change those to something nice and skip the opamps altogether.

Anybody?

 

[majkel]

See the datasheet if the op-amp buffer is just a buffer, or additional low-pass filter. Despite the DAC offers voltage output, it can still be insufficiently efficient to withstand loads, especially capacitive, like cables. I'm not talking about a possible damage just about expected sound deterioration but might be wrong so the datasheet would help.

 

[FallenAngel]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif See the datasheet if the op-amp buffer is just a buffer, or additional low-pass filter. Despite the DAC offers voltage output, it can still be insufficiently efficient to withstand loads, especially capacitive, like cables. I'm not talking about a possible damage just about expected sound deterioration but might be wrong so the datasheet would help.

http://www.asahi-kasei.co.jp/akm/en/...k4396_f00e.pdf

It seems the max load capacitance of the AK4396 is 25pF, but it also says "When AOUT drives some capacitive load, some resistor should be added in series between AOUT and capacitive load".

The datasheet example of the LPF also shows a 0.1uF coupling cap, maybe something to upgrade on this card.

 

[neongod]

Hi all,
I too have this sound card european version (the one with 3 NE5532) and want to upgrade them to better ones.

I have a couple of questions:

1) Do you know Analog Device AD8620BR OpAmp? Lot of people in DIY forums talks about it as one of the best OpAmps around, for sure superior to LM4562.
Also, someone on the Audiotrak forums tried a config with 3 Texas Instruments THS4032 and told it was really beautyful, better than 3 LM4562...

What do you think about it? Better AD8620BR or THS4032?

2) And it's better use a 2+1 config or a 3x config?


Also what about replacing all the caps? Do you think it might be useful? And what to use? Audience AV Auricap, Rubycon Black Gate, Nichicon Fine Gold or Elna Cerafine?

 

[anawatsao]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Since the AK4396 is a voltage out DAC, has anybody tried to bypass the opamps all together? Very interested as I just bought this card and since I have some very strong amps, I don't really want any extra line-driving opamps. I'm also going to be looking at the coupling caps on this thing, perhaps I can change those to something nice and skip the opamps altogether.

YES...

buffer tube or bypass cap.it work deep bass and detail.

 

[leeperry]

.

 

[Shoewreck]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Since the AK4396 is a voltage out DAC, has anybody tried to bypass the opamps all together? Very interested as I just bought this card and since I have some very strong amps, I don't really want any extra line-driving opamps.

There is a lot of ultrasonic noise coming out of such voltage out DACs, so the opamps are here to filter that rubbish out, not to drive the line. I'm not sure your strong amps were designed to handle out-of-audio-band frequencies.
You may use 560 Ohm resistors between DAC output and cable to filter some noise out. In this case don't forget to take care of DC offset.
A pair of audio transformers would also do a good job filtering out DC and ultrasonic noise. Just hook the primary between + and - DAC outputs and the secondary to output.

 

[moriez]

Im a owner of a HD2 as well and found more configs on the Audiotrak support forum. Thanks for this thread

 

[leeperry]

Quote:

Originally Posted by Hadakan /img/forum/go_quote.gif Isn't the headphone out as good as the opamps installed? As far as I know the two JRC4580 amps (which have dubious quality) are for optional boost of the signal. If I don't use the jumpers I'll get whatever the opamps create. Or do I?

if you use the HP out w/o the jumper, the JRC4580 do 70% amplification, and if you enable it they do 200%.

 

[leeperry]

.

 

[thoppa]

Quote:

Originally Posted by neongod /img/forum/go_quote.gif Hi all, Also what about replacing all the caps? Do you think it might be useful? And what to use? Audience AV Auricap, Rubycon Black Gate, Nichicon Fine Gold or Elna Cerafine?

Hi,

I don't have this card but I have done quite a lot of cap selection. What's the sound like ? Bright - warm ? Spacious - close ? You'll want to blend the sonic characteristics if you can to get your preferred sound.

I haven't heard the Auricap so can't comment on them. Black Gate are very good but perhaps not worth the money, they are quite spacious and detailed. Nichicon are very bright with good bandwidth (frequency range). Cerafine are the most neutral of your selection and probably the best value for money. I'd also consider Vishay/Philips BC (136) (musically neutral and strong performance), and Elna Silmic II (outstanding musical performance - best caps IMO).

Have fun !

Tom

 

[leeperry]

anything not harsh like the STX will do

I was told that the improved caps of the "Deluxe Edition" wouldn't really be worth it?

 

[thoppa]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif anything not harsh like the STX will do I was told that the improved caps of the "Deluxe Edition" wouldn't really be worth it?

I quite agree - the ST and STX are very bright and they use Nichicon Fine Gold almost exclusively. The KZ are supposed to be better but I suspect they'll still sound too bright. I've also used the HD and they are the same. Great for digital power smoothing but too bright for audio for my tastes.

I forgot to ask - what caps are standard ? What are used on the deluxe card ? It may not even be worth upgrading.

 

[leeperry]

yep, the STX/ST sound very agressive to me...very detailed and very harsh, really not the kind of sound I'm after...considering I got very transparent cans in the first place(MDR-CD1000 -same drivers as the CD3000- and DT770/600Ω)

this is the standard edition: prodigy hd2 - Google Images

Audiotrack Prodigy HD2 ADVANCE SE SoundCard - eBay (item 120457254934 end time Sep-07-09 22:18:13 PDT)

this is the deluxe: http://audiotrak.co.kr/images/advance_de_eng_04.jpg

AUDIOTRAK Prodigy HD2 ADVANCE DE Sound Card 2-Channel - eBay (item 120460571959 end time Sep-17-09 23:58:48 PDT)

I was told that the deluxe had a more detailed sound, but still very "digital" sounding...and the upgrade wouldn't really be worth it(it's only 12 EUR more expensive, but you can find the standard edition for pretty cheap second hand..)