Mackie 1202VLZ and PC Soundcard?

[buckman]

I have a Mackie 1202VLZ3 mixer and a simple 2 in 2 out soundcard (Digidesign Mbox actually via ASIO which has been great!)

Now I have connected all my sound sources into the mackie as normal and the Control Room out to my monitors..

Now I want to record any combination of the outputs of the mixer into my PC/Soundcard, so I have connected the MAIN OUTS of the Mackie to the Soundcard ins ( as the Main outs and the Ctrl Room outs are mirrored so i can hear whats going on through the speakers)

I then want to listen to the recorded PC track from the computer back in through the desk and monitors, so have connected the PC Soundcard back into the TAPE IN's.

Now I can flip between recording and playing back BUT the TAPE INPUT (you can monitor this via the buttons above the CTRL ROOM/SUBMIX fader) seems to have a audible tone/hum on it?

Its not too loud but noticeable, but when i switch back to main mix the sound has gone?

Anyone any ideas what this could be? or if there is an easier way to set up my mixer to be a patchbay and recording device?

I only have a couple of samplers patched in and muted those so its no those - its something to do with the TAPE IN??

Is there a better way to monitor the incoming soundcard? I believed that the Tape IN was best as this was uncoloured by EQ etc as i want to hear my finished recorded files as they are.

So just to recap simply : (and not confuse myself more!)

CTRL ROOM OUTS > Monitor Speakers

MAIN OUTS > PC Soundcard INS

PC Soundcard OUTS > Mackie TAPE IN

I have tried the guidlines in the mackie manual for the two different set-ups but obviously my gear differs slightly so have tried best i can with what i've got..?

Also Im quite apprehensive, as I dont want to fry the speakers by getting 5000db going through them due to me turning the wrong knob or using wrong outputs! (i do turn them off before any patch switching though )

Hope that makes some sense?!?

[UltraJv]

Sounds like your creating a feedback loop. Monitoring should be done via your application that youre using with the MBOX. That will allow you to switch between monitor and record. There will be a switch on the appplication to do that. I dont tend to record inputs from my small mixer so I dont use that config. Maybe someone else could help with the signal flow?

[Killvehicle]

Hmm Are you running 1/4inch out into 1/8 tape inputs?? If you are using any sort of cheap little clip-on 1/4 down 1/8 plug from radio shack, there may be a problem there.. Although it should work, In my experience the tape inputs arent as clean, so maybe the small amount of noise you are hearing is just the mixer.

I guess you could also run back into some open line inputs, say line11/12,(assuming you have a few left) and just monitor back thru those.. Just be sure while you are playing or recording you ARENT running your soundcard outs back into those inputs. So you may have to mute those inputs(I.E ,line 11/12) during recording.. Although you should be able to silence the soundcards outs during recording. SInce it sounds like you are monitoring your playing VIA the control room outs anyway...

[Chuck E. Jesus]

the first thing i'd check is to see if you have a ground loop...make sure your Mackie board, sound card, computer, speakers, etc (all the audio gear) are connect to the same gound plug, it sounds like that might be your problem...i would also use the ALT outputs as your send to the sound card, then assign the ALT monitor to the control room (then you can monitor your playing without any latency) ...also check that the "send to mains" button above the control room button is not pressed, that would be a feedback loop source right there...hard to tell exactly what it is without more info...

[buckman]

resigned myself to thinking it could just be noisy outputs on the soundcard...

[Chuck E. Jesus]

did you try anything?

[buckman]

I have tried various routing suggestions, and even put the powered monitors straight from the soundcard outs to the monitors to have a direct sound source and it seems like the "whistle" is still there when i turn the soundcard from "playback" to Input..

Is my soundcard the problem?

[C00kie]

I have tried various routing suggestions, and even put the powered monitors straight from the soundcard outs to the monitors to have a direct sound source and it seems like the "whistle" is still there when i turn the soundcard from "playback" to Input..

The last bit is the key to your problem...

Do I understand it right that with just the monitors connected to the card it's OK? And then you connect the mixer to soundcard input, routed by software to the output, and you get the odd sounds? And by skipping the soundcard it's OK again?

Since there are three devices chained it still could be a grounding problem...

[Chuck E. Jesus]

I have tried various routing suggestions, and even put the powered monitors straight from the soundcard outs to the monitors to have a direct sound source and it seems like the "whistle" is still there when i turn the soundcard from "playback" to Input..

Is my soundcard the problem?

possible you have a loop routed in software? do you have something plugged into the soundcard with this last test?