Random Dropouts without Xruns?

[Zen:Core]

Hey all. Long time.

I've been recording the band and I'm getting weird random dropouts on the system. I'm hoping someone might have some ideas on where I should look next.

The recording rig is a Core2Duo with 4 Gig of ram. A Delta1010 (the one with the breakout box) and an old EV BK-142 mixer to get everything into the card. I'm using the half plug method on the mixer inserts to get the sound in the card. On the software side I'm using Crunchbang Waldorf (Debian Testing) with the 3.2RT Kernel. We've been using Qtractor (5.6, but I just compiled 5.7 last night) this whole time. The only plugin I use while recording is the Simple Amplifier to run the Metronome into a separate bus and give the click a little more oomph when we're recording drums. We monitor the drums off the mixer and send the Click and scratch to the mixer for monitoring. I set up jack so that all of my inputs are just ins and then I give the drums thier own Stereo out Bus.

Okay, so the problem is that everyhitng has been going great until now. We've got the back half of 2 songs left on this first phase and I keep getting random dropouts in the audio. We've recorded six other songs without a problem. The dropouts just happen, you can see them in the waveforms in Qtractor. It's just for maybe a half second or a breath no sound in that one small area of the recording and it happens over and over with an undefined spce between them. More rarely there's a pop that is repsented by a small upside down triangle at the end of the waveform. When the Dropouts happen they happen across all 8 tracks that are being recorded.

When this first happend we got flustered and moved on to the back of another song and it recorded fine (one more in the bag right?) Then we moved onto another song and it happend again. The 2 songs this has been happening on both have a back half at a different tempo then the first. I thought it might be a bug and that Qtractor wasn't happy about the differing tempos. I got rid of the second tempo and just used one, but that didn't help. I also made new projects for the back halves, but that didn't work. I went so far as to make new projects and cut new scratch tracks, but still no joy. Now the best part of all this is that, we've recut scratches for tempo changes on these parts and done some other guitar related changes on the scratches and added some vocal scratch and this problem hasn't reared it's head. Some time ago, to get familiar with the system I recorded 3 tracks of guitar (DI, PSA 1.1 out and PSA/GSP1101 with impulse combo), and never had a hiccup. Only on the Drums and only on these 2 songs. When it happens I get no Xruns and there's nothing in the message output of Qtractor or Qjackctl. I do however hear a pop or drop in the headphones when we're moitoring.

So far to work this problem I've:
1. Removed Pulseaudio from the equation and tell Jack to stop using Dbus.
2. Dumped the Scratches into Ardour and tried recording with it, but it happend there too, so it's not Qtractor.
3. My CPU's never max (or even get pushed hard for that matter) and I'm only using about 400mb of Ram at any givin' time.
4. Still plenty of room on the Hard drive. (Over 490GB left. 7200rpm drive with noatime in the fstab.)
5. Raised my periods buffer in Jack and even tried to lower it just for giggles. (Jack has ran at 2.45ms latency @44.1k fine this whole time. I raised the periods to 128 instead of 64 and it still happened.)
6. I thought it might be the Ogg scratches having an issue with the FLAC recordings and nope that didn't affect anything.
7. Tonight we're going to try a different mixer.
8. Tried to get it to do it on guitars, but I just can't get it to drop. So I think it's fixed until we start recording the Drums again.

So, there we go. I've got no error messages on the software side, so I'm starting to think it's hardware unless there's something I've missed. Has anyone had any issue like this? Might it be the Delta1010? I really hope it's not the Delta. While I'm out today I'm going to grab a new printer cable for the Delta. The one that goes from the brakout box to the card. Maybe that's the issue, who knows.

Sorry if this post was a bit rambling. I 'm trying to get as much info on what it's doing and what I've tried to fix it. Mix that with trying to quit smoking and the words and grammar don't always make for "good words type on screen."

Any help or ideas is greatly appreciated. I'm kind of at a loss as to what might be happening.

[Alwaysanewb]

I use the delta 1010 and as good as the driver is it's a little sketchy sometimes. If I'm recording certain bpm in ardour the click drops out at certain times on the clock like at 5min on 56 bpm the metronome just goes dead for 4 beats. It doesn't happen with my art dual pre with generic usb drivers. It's not that big deal for me I just change the bpm up one or down one and it's fine but then again I don't have songs half recorded already using certain bpm when I'm doing it.

I know that might not help a lot and might even not be what's going on with your system but my guess it's just something finicky with the 1010 drivers.

[Zen:Core]

It looks like the problem is the mixer. We tried a different one and didn't have the dropous. For the sake of being thorough we tried the original mixer again and we got dropouts again. So, I guess my system tuning skills hold true again!

So, now I've got a bid in on an maudio octane to mate with the delta......