Modding the RME PAD
Mar 31, 2004 at 7:53 AM Post #226 of 243
The sound is definitely more well definied and direct. I think this is a definite improvement, though I can't directly compare to anything else. The high end definitely sound more detailed and realistic then before, drums have a more immediate slam, and lead instruments jump out at you more.

The beauty of it it that almost anyone with a soldering iron and a pair of caps could do this mod.

And Sduibek, in case you're wondering, this does not mean that you go screwed over, since this setup is not appropriate for directly driving headphones, so you would have been out of luck until your amp arrived.
 
Mar 31, 2004 at 8:01 AM Post #227 of 243
Glad to hear you're liking it. It's a different flavor -- no op-amps, no feedback, no analog filter. IMHO detailed but completely non-harsh highs, and fast, fast, fast. The bass should fill in more as the caps burn in.
 
Mar 31, 2004 at 8:11 AM Post #229 of 243
In a way, it's almost a totally purist solution -- you've got data coming from a buffer hung off the PCI bus, so you've got vanishingly little jitter, and the analog stage is as pure as can possibly be (well, except that there's a cap in the signal path, but hey, can't avoid it). Kind of cool.
 
Mar 31, 2004 at 8:19 AM Post #231 of 243
Quote:

Originally posted by Iron_Dreamer
The sound is definitely more well definied and direct. I think this is a definite improvement, though I can't directly compare to anything else. The high end definitely sound more detailed and realistic then before, drums have a more immediate slam, and lead instruments jump out at you more.


Well, I guess I'm keeping one of my cards stock for awhile so we have the baseline for comparison.

I'm not sure if I'd want my card more foward with my K1000's.

Now my R10's on the other hand......

Did you do the noise test? Cranking the amp with nothing playing.

-Ed
 
Mar 31, 2004 at 8:23 AM Post #232 of 243
RMAA test of the new mods compared to the test results I saved when the card was new.

Also cranking the amp the noise that was present before seems slightly quiter, and less complex, as if it is made from fewer individual sounds. Totally inaudible at normal levels of course.

Also, I wouldn't say the sound is more forward, just more direct, as if it has been muddled with less along its' route to my ears. It is definitely much cleaner, and the high end is more detailed, yet if anything smoother and less harsh than even my previously modded card. FASTER is the main way I would describe it, it is almost like going from dynamic cans to electrostats in that regard, since the macro and microdynamics are more responsive to quick changes then ever before.

The more I listen, the more it seems like as big an increase over the previously modded card as the previously modded card was over stock.
 
Mar 31, 2004 at 8:28 AM Post #233 of 243
Interesting that IMD increased (from -109dB to -92dB at 120 Hz). A significant increase, but shouldn't be audible. General noise levels decreased (probably inaudibly as well, and probably due to skipping the analog amplification).
 
Mar 31, 2004 at 8:33 AM Post #234 of 243
Interesting how the dynamic range and noise level actually get better even though it's now running single-ended vs. balanced. Not something that would have been predicted, but a nice result nonetheless.

The THD and IMD have increased marginally, probably because there's some residual ultrasonic noise. But the overall distortion profile is still very nice, and you've got a blacker background because of the lowered noise floor.
 
Mar 31, 2004 at 9:22 AM Post #238 of 243
I'd think this mod could be done with any decent card, like the Revo or Terratec EWX (not that I'd know how to do it, meself
wink.gif
).
 
Mar 31, 2004 at 9:25 AM Post #239 of 243
I guess Wodgy would be the one to ask, but it seems to me that as long as the card has a DAC chip with voltage output (as opposed to current) it whould work. You can find that out by finding the dac chip on the card, typing it into google, and looking at the manufacturer's datasheet. Of course you'd have to be able to find the appropriate solder points, but that shouldn't be too hard.
 
Mar 31, 2004 at 9:31 AM Post #240 of 243
Any card that uses a voltage output DAC (current output devices won't work) and that has an output stage that can handle light but nontrivial loads. The EWX would probably be a good choice; all AKM DACs are voltage output devices (the Sonica design, using an AKM DAC, doesn't even have an analog stage). I think the Revo uses an AKM DAC too.

Keep in mind that part of the reason this sounds so good (and why the IMD doesn't increase all that much) is because the AD1852 has a great digital filter. If you do this mod with a DAC with a -60dB stopband, you'll get improvements but they'll be offset by a large increase in IMD. This may still be okay. Heck, the Ack! dAck! has no filtration (and I would gather very high IMD) but people still like its sound. Still, I'm not sure I can recommend that sort of thing without reservation. Also, if there isn't a good digital filter, you have to watch your tweeters if you're going to be using this with speakers. (You have to do this anyway with filterless designs like the Shigariki.) I don't want to be encouraging anyone to try stuff blindly that will fry their tweeters.

That said, experiment away!
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I think it's cool that Iron_Dreamer's setup (with Gilmore) now has no op-amps anywhere in the signal path.
 
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