Issue with 8PRE totally crapping out

[thesixgun]

Hello there all.. Hoping someone might have an idea of what the heck is going on.
I am running a MOTU 8PRE firewire connected to a macbook pro (2.5 ghz core duo, 4G ram), and Logic Pro 9. I also have an external hard drive hooked up via the other firewire port on my macbook. I use this setup as my mobile studio to bring around to my bands practice space and record demos.

The 8pre works fine when it is hooked up at my house on my desk, but the most i ever run through it is one track recording guitar through an amp simulator plugin, or a MIDI keyboard. most the time i am just using the stereo out and mixing.

When i bring it to the practice space however, this is when the problems begin. This has happened the last 3 times I have tried to record a full drum kit. I set up about 5 or 6 mics on the drumkit, have inputs 1-6 enabled, maybe two or three of them have phantom power on. the 8pre is set at 44.1, logic usually like 256 sample rate, recording delay at 28 samples, right in the middle. I set up a click for the drummer (i usually turn all the channel faders down, turn the stereo out channels EQ master gain up much higher than 0.. because the click in logic is NEVER loud enough) and press record. After about 30 seconds to a minute of recording with no issues, the sound of the click begins getting extremely loud, and starts to sound like its being run through a bit crusher that is turned to 11, like total digital distortion, until it gets too loud to listen to through the headphones and the whole session is just done from there. Then this digital distortion is running through the stereo out for every input when i turn the record enabled tracks back up. If i restart logic and power cycle the 8pre, it will work again for maybe 30 seconds to a minute or two, if im lucky.

I take the 8pre back home, and it works fine again. Ive reintalled all firewire and whatever else updates from the motu site, reinstalled the 8pre's firmware.. I have reinstalled logic.. I just cant figure it out. I have recorded using all 8 channels at once dozens and dozens of times before and never an issue. this is just the last 3 times ive tried.

any ideas? maybe a clock issue? The only thing different im doing from when it worked to now is I used to daisy chain an external hard drive through the 8pre, now i have it hooked up to my macbook. thats because i got a new one and it uses the bigger pin firewire cable.

[mikehalloran]

It sounds like the FW bus doesn't have enough power - weird as the 8pre doesn't run on bus power.

Are you using bus power for the external drive? If the answer is yes, I would use a powered external and see if that doesn't fix you up.

You probably know that only one of your FW ports provides bus power. The 8pre does not need to be connected to it as it runs on AC.

These are things to look at. It would surprise me if this were the problem.

[thesixgun]

interesting. Could it have anything at all to do with the fact that the spot this happens at has not near enough amps running through the electrical wiring? I know my tube amp sometimes crackles and the lights dim when everyone is plugged in and playing.. something isnt putting out as much power as it usually does when its hooked up elsewhere? i will try it without the external all together and let you know.

[mikehalloran]

interesting. Could it have anything at all to do with the fact that the spot this happens at has not near enough amps running through the electrical wiring? I know my tube amp sometimes crackles and the lights dim when everyone is plugged in and playing.. something isnt putting out as much power as it usually does when its hooked up elsewhere? i will try it without the external all together and let you know.

It could. Apple and MOTU power supplies are somewhat forgiving but they can't create juice where not enough exists. Phantom power does increase the power requirements for the 8pre. If you are operating in brown-out conditions, that is your likely cause. Radio Shack used to sell an inexpensive LED volt meter that I would plug in when doing live sound - saved my equipment many times.

[thesixgun]

thank you sir. turns out it was a single outlet that I always plugged into . it wasn't putting out enough power. plugged into another one that my bassist didn't wire up , and it worked perfectly.
problem solved.
Chris.