Adjusting Recording Volume from Cassette


I have a Denon DRW-660 dual cassette deck and I’m embarking on a project to digitize many old cassettes. When I listen to many of these really old cassettes (some upwards of 30 years old), they still sound pretty good.

Here’s a description of the connections I’m using:

  • RCA (red/white) out from cassette deck to dual RCA (this is more like an extension cord because both ends are male)
  • female RCA connected to above termination ending in an 1/8-inch jack which goes into iMac. The 1/8th-inch tip is TRRS.

So, essentially, I have the cassette deck pretty much plugged directly into the iMac. The TRRS dermination makes the sound input setting go from internal speaker to external microphone (I can watch it change after I plug it in). This gives me levels.

Now, when I play back what I’ve captured in Audacity, it’s ALWAYS overmodulated and sounding much worse than the source. I’ve fiddled with the recording volume slider and the GAIN slider (this appears when you open a new track) and only the recording volume seems to make a difference. But, no matter how much I bring down that slider, it’s always overmodulated.

I’m thinking the connection to the iMac may be the weak link but I suppose something with Audacity could be at fault too.

If someone wants me to post some of the captured audio (overmodulated), I can.


The TRRS termination makes the sound input setting go from internal speaker to > external microphone

It looks like you are feeding a line level signal into a microphone input (and a mono one, at that). So the distortion is happening before the sound reaches Audacity.

You don’t say which iMac you have. Newer (since 2011, at least) ones do not have a stereo line-level input.

You’ll need an audio-to-USB adapter. Some of us here use the Behringer UCA-202 or the UCA-222.

– Bill