distortion

[robjh22]

I got 2 related questions: for those of us using condensers mikes AND mike preamps, how hot are you running the preamp when you record? I put mine at a bout 60% and the internal pre of the Fostex at about 5%. It was working well for acoustic guitar, but ...

When I over dub voices, the cumulative effect sounds a little distorted, i.e., more distorted than either vocal track played back alone. Any idea why?

 

[billisa]

I suspect that somewhere the signal is overcooked. Input of the mic to the preamp?/output of the preamp to the Fostex?/input of the Fostex?... How much gain others are using doesn't really help you because the real issue would be how much gain do you need on your particular equipment. When I use an external pre, the ones on the VF80 are turned all the way down. At that point I could get distortion by having my input from the mic too hot, or my output from the pre too hot. Make sure you're metering both the input and output on your pre. (Plus the meters on the VF80).

Now if the tracks actually have NO distortion individually, then perhaps with their cumulative levels you are peaking. When you play back on the VF80, the individual track LCD's show what was recorded on the hard drive -- regardless of where you set your fader on playback... When playing back, remember that the peaking LED's aren't in the loop. What are your L/R meters showing? They should be hitting at or just below the top dotted line.

In general, peaking doesn't sound like distortion... If the Fostex was peaking, you'd know (its sounds like crunching metal)

So... that leads me to suspect the problem may be in the preamp levels before it gets into the Fostex. Also, are you dialing in too much tube? Perhaps cumulatively it's too much...

Hope this all makes sense. You'll track it down.

 

[dwillis45]

I’m not sure what recorder you are using (Vf16/160 MR-8) but you might want to examine how your preamp is hooked up to the Fostex. I use an external preamp which is wired via the inserts on tracks 15-16. According to Fostex’s block diagram, hooking the preamp to one of the 1/4” line in jacks will send the signal though the onboard preamp. Using the insert, the diagram indicates that you bypass the preamp. What are the consequences? Distortion? Noise? I don’t know for sure but at least one audio guy I trust told me to avoid the issue by using the inserts. Of course this means using special cables, recording on 15 and 16, and doing alot of track exhcanges.