PC Sound Card (external) DIY thread - start throwing ideas

[halcyon]

How about modding a PC audio sound card for improved audio output and input?

Goals:

1) peer-select a suitable sound card for modding. Preferrably external sound card (easier to mod, when one doesn't have to keep pulling out a PCI card all the time. Also external units are easier for PSU mods and RFI/EMI rejection). Interface either USB or Firewired. Price top $400/400€, so things don't get out of hand immediately.

2) Photograph and analyse the innards of the box to identify potential places for upgrades & improvements.

3) Implement, test, listen & discuss. Go to (2).

Anybody interested in sharing a project like this?

I'm a beginner diyer myself, with very rudimentary skills, but a willingness to learn and try things out.

My goal would be personally also to get a good working sound card out of this (hopefully). That is, not only learn and blow things up, but make something that works better as well. Still, learning would be my personal main objective.

I can get the ball rolling on (1) "potential sound cards", if anybody's interested in sharing such project here?

Otherwise, I'm on my own, I guess

Any interested parties out there?

cheers,
Halcyon

PS This is based on an assumption that even so called professional sound cards at this price range can be improved on some/all of the following areas: clock, headphone amplifier, power supply / related filtering, simple parts upgrades (caps, converters, sometimes even DACs).

[pinkmouse]

As long as it works out Mac compatable, I'll help. However, I'm not so hot on digital, but I am more than willing to lay out the pcb.

I think it should include at least one xlr mic channel with pre, so it can be used for measurement purposes.

[00940]

According to a thread on head-fi ( http://www6.head-fi.org/forums/showt...b+asynchronous ), the newest creative audigy 2nx uses asynchronous transfer for USB. If this is true and we can hack the card to just get I2S or similar protocol (big if), we can have an external soundcard free of any problems related to jitter.

[halcyon]

It's great that there it at least some initial interest!

I think all Audigy gear must be ruled out by default

Reasons:

1) No proper Mac support

2) Resamples everything below 48kHz to 48kHz. Imho, a big no-no for those of us who'd rather not upsample in software before going to the sound card. No digital bit-perfect output at 44.1Khz. Can only be bypassed on _some_ Audigy models, using _hacked_ (3rd party) drivers. Rather not go through the hassle.

3) Default drivers leave a lot to be desired in terms of Kernel Streaming, ASIO, etc. support (I'd rather not start hacking the drivers too)

4) No xlr-input (with proper mic pre-amp).

I think there are much better option in terms of of sound quality (Mac compatible, external, with at least one XLR mic + pre-amp).

The following borrowed from another thread at head-fi ( http://www4.head-fi.org/forums/showthread.php?t=112165 ).

Focusrite Saffire, c. $400
http://www.focusrite.com/products/saffire/index.html

M-Audio Firewire 410, c. $400
http://www.m-audio.com/products/en_u...e410-main.html

Edirol FA-66, c. $380
http://www.edirol.com/products/info/fa66.html

Presonus Firefox, c. $350
http://www.presonus.com/firebox.html

ESI QuataFire, $350
http://www.esi-pro.com/viewProduct.php?pid=16&page=1

What other requirements should the external card pass?

regards,
halcyon

PS. I'm adding a couple of points to the requirements (good additions pinkmouse!):

1) bit-perfect at 44.1kHz for digital output and before DAC
2) Mac support
3) minimum 1 XLR mic channel with mic pre-amp (for testing)

[halcyon]

I dug up some additional info on the cards above:

ESI Quatafire 610
- 24bit 192kHz DA converter; 112dB dynamic range (specs)
- 24bit 96kHz AD converter; 107dB dynamic range (specs)
- Support 44.1 - 192kHz sample rate
- uses AK5385AVF / AK4358V0
http://www.ezguide.co.kr/auto_page/01080100/12451.html
- Review in Russian: http://www.musicmag.ru/info/soundstu...ndhard2003.htm
- measurements from here (24/96, playback/recording):
http://www.watch.impress.co.jp/av/do...7/dal161_3.htm
http://www.ibsenstudio.no/prod/esi_p...rightmark.html
- somewhat problematic drivers (?), not very good interface (not that it needs to be used for non-recording stuff, necessarily)
- Mac drivers being improved upon, now works with standard OS X firewire audio drivers (less than optimal)

M-Audio firewire 410
- AK4381 / AK4355 used (depending on output/headphone)
- op-amps for output LMV722
- some measurements (RMAA, loop-back and via LYNX) at:
http://www.ixbt.com/multimedia/m-aud...wire-410.shtml
- not the absolute top notch measurements or subjective sound appraisal from reviews
- low line output
- good drivers, DirectSound also works ok
- works well on Mac

[b]Edirol FA-66[/b}
- RMAA test results:
http://www.watch.impress.co.jp/av/do...0221/24_96.htm
http://www.watch.impress.co.jp/av/do...221/24_192.htm
- sample rate switch selectable on the back (?!), no 88.2kHz support ready (surely the chips can do it...)

Focusrite Saffire
- not much info yet. Apparently not shipping yet (?)

I'm trying to hunt down some pictures of the boards inside the boxes of each one.

[halcyon]

This is what M-Audio Firewire 410 looks like inside (roughly)


http://www21.brinkster.com/roina/mau...re_410_pcb.jpg [JPG, c. 700kB]

The upper additional board I didn't dare to remove, because it was my friends card and it didn't come off even with slight force.

That's one minus for modifying this (as it's not super easy to remove the smaller pcb nor work under it).

I haven't been ablo to get my hands on the other cards.

I will post updates as soon as I do.

[halcyon]

I'm continuing this as a public memo of sorts.

Please chime in, if you know about the devices in question or want to add something.

I just testd Firewire 410 for basic things like clipping/aliasing. Seems to pass them audibly ok.

However, I can't find a possibility to selec the input signal level, so attaching unbalanced devices to Firewire 410 results in a loss of -10dB in signal level (cannot be compensated for in the true-line level stages, only if one goes through to the mic/preamps inputs in the front, which i didn't test).

I think most of the above devices are made by BridgeCo based on a very similar reference design:

http://www.bridgeco.net/products/beb...ustomers.shtml

Focusrite saffire is not yet on that list, so it could be a different design.

Then again Focusrite is already using BridgeCo reference designs in their other products, so maybe not

[soongsc]

Would it be reasonable to consider a digital chip amp which is power effecienct and small?

[Vikash]

Have you made any conclusions halcyon? I'm about to purchase one of the above after just having returned a M-Audio Audiophile Firewire which kept dropping connection.

At the moment I'm trying to pick between the ESI Quatafire 610 and Edirol FA-66 so your (and anyone elses) input will be very much appreciated!

[halcyon]

Sorry for no updates.

I had to postpone my purchase due to other arrangements (both timewise and also moneywise).

I'm trying to get back on track.

I'm not too happy with the comments on most of the BridgeCo models (esp. Edirol and ESI). They seem to have all sorts of problems with dropping connections, etc (according to users in various forums).

One option would be the E-MU series, which are quite good to start with. It's just that they are quite expensive. The external sound card option from them is the PCMCIA/PC-card version (1616m). One needs a PCI-to-PC-card adapter if one wants to use that in a standard desktop PC. Modern laptops should be fine and it would make a good portable setup.

If anybody has other contenders here to consider, please post.

I'd go for the E-MU 1616m myself, but it's too expensive at c. 500USD (even more in Europe 522€ from Thomann).