Delta 1010LT problem...maybe.

[punkin]

Many of you are aware that I'm a big fan of the Delta 1010LT product. Big bang for the buck but I think I may have a problem. Tell me what you think.

I recently clean house...got rid of some cheapie toob pre's and cleaned up some cabling which was abandoned inside and behind my console. I'm guessing you're likely to dwell on this...righfully so but hear me out.

I got a little carried away and went into a neat freak frenzy. I pulled everything out, dusted out the gear and put things back together. I have a couple 1/4" patch panels into which all my audio source outputs are plugged into (mic pre's, DI's, mixer channel inserts and such). Then, I have a couple patch panels for the recording DAW inputs (I've got more than one DAW and audio interface...I'll spare ya).

Today I went to set up for a small combo session I've got scheduled for this weekend. I was planning for 8 simultaneous channels. All looks fine except for channels #7 and #8. With two seperate mic pres patched to #7 and #8, hit record arm and both channels immediately register about -24 on the VU. Remove the patch cord from either channel and the remaining patched channel looks ok and records just fine. I can reverse the channels (use either channel or either mic pre) and the result is the same, I simply cannot use both DAW channels at the same time.

I looked into the Delta Control Panel to make sure something wasn't patched over in there but not. Again in the Delta Control Panel, when this thing is acting up, it things that there is a lot of audio being supplied to the input when there isn't any.

Sorry for the long post...any thoughts? Help me before I pull out that one last hair and let me tell you...it ain't on my head

 

[punkin]

OK...OK...check this out!

To further clarify...the two mic pre's in question are side by side in the patch panel (Jacks #1 & #2) which I was trying to patch to DAW channels #7 & #8 (Jacks #7 & #8) which are also next to each other...duh.

If I simply move the patch cables into the DAW say channels #5 and #7...no problem. But, if I move them to say #5 & #6, the problem reappears on, ...you guessed it channels #5 & #6.

 

[dgatwood]

OK...OK...check this out!

To further clarify...the two mic pre's in question are side by side in the patch panel (Jacks #1 & #2) which I was trying to patch to DAW channels #7 & #8 (Jacks #7 & #8) which are also next to each other...duh.

If I simply move the patch cables into the DAW say channels #5 and #7...no problem. But, if I move them to say #5 & #6, the problem reappears on, ...you guessed it channels #5 & #6.

Weird. Doesn't sound like something wrong with the Delta. Sounds almost like maybe you have some sort of bizarre ground loop problem. Are all the cables firmly plugged into the breakout cable? Are they firmly plugged in at the other end? Is the breakout cable plugged in firmly? Did you by some chance partially dislodge the sound card inside the machine?

 

[punkin]

Thanks for the reply...

The weird thing is that I'm actually using 6 inputs simultaneously. I have two avalons, an MPA Gold (2 channels) and a DMP3 (2 channels). They're all plugged in and record enabled. The two avalons when plugged jacked into the Delta patch panel seem to not want to be plugged into adjacent positions. Split them apart and all is well.

This hurts to think about.

 

[Alexbt]

Perhaps something gets crossed? Or maybe phasing and that? I dunno. It sure sounds weird.

 

[punkin]

Well, I found out what the problem was...if anyone still cares...maybe one to keep in the back of your mind if nothing else.

I'm not too proud to admit it but, I do have some cheap gear in my humble racks. Yes...a couple TOOB pre-amps...hey...they work decently as DI's for keyboards and bass once in awhile...they're Presonus TubePre's.

I have them mounted on a universal mounting tray. The TubePre's come with a tapped mounting hole in the bottom of the chassis (metal) and coincidentaly, the mounting tray has a matching hole. I secured the TubePre's using a proper screw. But here's the clinker. The TubePre's aren't grounded throught the power supply cuz they use them wall-warts but my power strips and racks are grounded/earth via virtue of real grounded chassis' equipment mounted nearby...when the TubePre's are mounted to the equipment tray, they create a ground loop between the audio side circuits and the chassis. The big fix after talking with the folks at Presonus for several days was to remove the screw and fasten with velcro.

AWWW common...don't give me any crap 'bout the "TOOB" gear...this could happen with a number of other devices powered by wallwart supplies too ya know!

FWIW