Restoring a tape that was recorded using AGC?

[edsel58]

Hi,

I am trying to restore a "live" band recording, which was taped using a cheap stereo cassette recorder which uses AGC (Automatic Gain Control), unsparingingly. There is quite a bit of "pumping". Is there a way to "reverse" that effect, somewhat, using DC-Art, to smooth out the sound level?

The recording quality itself isn't too bad.

Thanks! Warren

[Craig Maier]

Re: Restoring a tape that was recorded using AGC?

There were no standards for Cassette tape ALC/AGC time constants and gain ratio's. However, the Diamond Cut Dynamics Processor allows you to reverse these processes, with variable time constants & expansion and compression ratios. You will have to "experiment" to find the correct values for these paramaters to correct the initial applied AGC by the recording Casette deck.

[Dan McDonald]

Re: Restoring a tape that was recorded using AGC?

If you are getting short bursts, such as when someone ups or lowers the gain control by hand quickly (ah, yes...I remember the old days of making tapes in the dark in stadiums), I've had good luck creating a duplicate file and opening it as a destination file. Then I highlight the area that is bumped up or back and click on the "convert files", leave it as it is (stereo or mono) and just raise or lower the dB level as needed. Takes a little practice, but works great when you have someone who was too fast in adjusting for sound differences.

Dan McDonald