comparative qualities between windows and linux ice1712 chipset drivers

I’m going to have to be the bad guy and say this, but first I’m going to start off with a positive. Ardour isn’t LIKE protools… I think it’s better in many ways.
I think it is a well designed piece of software.
Now with the negative…

I purchased about 4 months ago a delta 66 and a delta 1010. I never tried either of the cards in windows, but I tried syncronizing them with a MMAP_COMPLEX patch for jack and a pcm_multi patch for the newest alsa-lib. With jack patched and running both cards in sync, I was getting wierd phasing issues and some very unnatural sounding hardware monitoring. As a vocalist amongst other things, I was noticing strange behavior with backing harmonies and pitch issues between accopaniment and vocals. It is common knowledge that singers normally sing FLAT when a headphone mix is a bit hot. Singing slightly flat on a note or two usually goes unnoticed, but I was getting frighteningly weird behavior with backup harmonies. They were SHARP!
Not only that but there was much to be desired in the recording with both high and low frequency definition. My recordings were not sounding professional. I then got curious, installed windows(yuck!), and tried out the windows drivers.
The resolution quality of the hardware monitoring was like night and day. Using the exact same settings I had on the envy24control mixer, with the windows hardware monitoring on I could hear the fish tank in the next room. It was crystal clear, which made me realize that these delta cards are supposed to sound JUST LIKE THE RADIO. It is my understanding that they even use the same AD/DA converters as the ones in protools HD systems.
I’m not a professional computer programmer, but if you’re willing to take my word for it, I’m actually a well-respected musician. The sonic quality difference between the linux and windows drivers is like night and day. It almost sounds like the linux driver is only sampling at 22050 HZ instead of at 44100. If you listen carefully to the playback the linux recording quality almost sounds like half of the data is missing.
I would have never known any of this until I configured a dual-boot system and was able to do a side-by-side comparison.
So, in conclusion, I think ardour is an absolute gem, but I’m forced to use windows right now so that I can submit a radio-quality demo. Perhaps if some genius out there was willing to sign a non-disclosure agreement and SELL drivers that work flawlessly with linux, I’d be their first customer. Techies love to tech. Pro-grade musicians want pro recordings, and they can’t be second best or just okay. They have to be BIGGER THAN LIFE.
I don’t think anybody is going to have a problem shelling out hard cash for linux solutions if they know their rig if going to work flawlessly in linux, but it’s just that. The hardware really has to WORK FLAWLESSLY.

            I commend everybody who has worked so  hard, but I think it is only fair that I let out the  bad news.

I am always interested in ganging cards together, but the #1 issue in doing so is maintaining sync.

If I remember correctly (and I recently looked it up), the Delta 1010 and 1010LT are the two that have wordclock, the delta 44 and 66 do not.

So running a Delta 66 and Delta 1010 means that there is no hardware solution for maintaining sync.

(!!Unless!! the 66 offers syncing over SPDIF, the 44 has no digital in/out)

I can imagine what you are talking about when you spoke about a wierd phasing kind of thing, as this sounds exactly like a sync-drift issue.

The only way to correct for drift (sync) is in software (unless the delta 66 offers sync via SPDIF).

The brute force way to deal with drift is to drop samples on the faster card (or duplicate samples on the slower card). The better way is to interpolate (bezier path-like, or similar) samples lost or gained.

As I am not sure as to the MMAP_COMPLEX patch for jack and the rest of that, I suspect that the method (if any) for correcting sync is less than optimal.

Eventually, multi-card support will be more common place, but it best to use sound hardware that supports wordclock (over BNC or via SPDIF).


I know you want two cards working, but did you try with just one card? I suspect your problems are with ganging the two cards together.

Also, the sync settings are another possible culprit.

When I was testing the sound quality I wasn’t syncing the cards via spdif or in any other way. I was using only one interface at a time with the jack server so as to rule out any kind of drift or sync problems. I was actually conducting the test without MMAP_COMPLEX using the most recent release of the jack server which doesn’t have MMAP_COMPLEX support. Seriously though, if you have a dual boot system of any kind you’ll HEAR the difference, especially with hardware monitoring and recording quality. It’s not nit picky, it’s OBVIOUS. Even with one card, there’s a big difference.
When I first started recording on this box, I only had a delta 66, but from hearing old mixdowns with the delta 66, the same sonic characteristics exist. If I were only using a linux box I may have thought the resolution I was getting was just the way the card was supposed to sound, but it’s not. Something is very different.

ice1712 chipset devices work very well. My apologies to the community. Please disregard my comments…

As soon as I physically removed the spdif cable from my cards, the sonic quality was excellent. Perhaps I’m uninformed about syncing via spdif?
Any comments in this area would be greatly appreciated. I just want to understand what I did wrong. Thanks.

the ice1712 chipset is one of the most widely used and best supported chipsets for linux. there are dozens of people who use it with linux and windows, and the quality issues you are reporting are either not common or have never been reported in any forums or mailing lists i am familiar with.

i wish i could be more specific about what the problem is, but i hope you will trust me when i tell you that there are a lot of very satisfied users of ice1712-based devices (especially the delta 1010) on linux, and that in this sense, the drivers “just work”. these are not all naive users - many of them are experienced audio engineers and self-recording musicians.

rather than advocating that someone needs to write new drivers, you should join a mailing list (linux-audio-users or alsa-devel) where you could get very detailed and expert help on what might be wrong.

you could also try the #ardour and/or #lad IRC channels described on the support page on this web site.

Is it possible to just delete this topic? I’m embarrassed.
I’ll do what you recommend and see if I can solve the problem some
other way. Sorry… I won’t bug you guys any more.

My delta 1010 is now working great. I tried everything except unplugging the spdif cable I used to try to sync the cards. Now my delta 1010 sounds like DY-NO-MITE! The high and low frequency clarity is fine. I appreciate everybody’s input. Ultimately I was just frustrated because I wanted my linux box back.