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Audio really bad on cassette transfer

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Walkingdead

macrumors member
Original poster
Apr 16, 2024
36
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I'm using a tape recorder plugged into a behringer interface into my iMac mini M1. I'm using audacity. I've tried all different settings but I still get a loud hum over the audio when recording. I don't even have to press play to hear the hum on the recording. I checked the cables and everything seems fine. Any advice to fix this would be appreciated.


Picture of setup and video of good audio from tape and bad audio when recording
 
Sounds like it could be a "60 cycle hum" (or 50 if you're in a country with 50Hz AC power) AKA a "ground loop".

You might try a different outlet for the cassette recorder.

It's the kind of thing that can happen when two devices are plugged into the wall and then connected together. Often it's because they're plugged into two different outlets that are on different circuits in your home/office electrical system…but it can happen on the same circuit also.

I've had this kind of issue with and putting a "ground float" adapter on a three prong plug sometimes fixed it. I imagine if the cassette machine was running off battery it wouldn't be happening.

It's possible that a better quality RCA audio cable might eliminate the hum.
 
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These chinese signal cables, put them recycle bin. Their shielding is non-existent

Also, make sure that wifi devices are well away or turned off.

Finally, have an electrician check the grounding circuit, if it is not working properly, a ground loop will occur.
 
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Ground loop hum. It's happening because voltage is getting introduced into the circuit somewhere without a path to discharge it to ground. The most common culprit is these cheap Behringer interfaces. The other problem is when attempting to use a headphone out instead of a line level out. The headphone out has different voltage and impedance than line level, and that bit of current is being amplified by the Behringer device into the RCA line that is expecting a line level signal.

Use a tape deck that has line level RCA outs and go a clean RCA to RCA cable with no adapters. NEVER go from a powered output to a line level input.
 
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I don't know how to word this so it hits you less hard, but you're never ever going to get acceptable SQ from those kind of 'shoebox' cassette players in a thousand years: they're bad quality to start with, and even if they weren't bad quality, using the headphone output (which is amplified, basically straight from the speaker) to connect to the line-level inputs of your sound-card, is just never going to give good results anyway because the impedances and levels are totally mismatched. You need a proper cassette deck with RCA outputs at the back.

EDIT: this is basically the exact same advice I gave you in your previous thread of December 15th. It's too bad you didn't follow it, because absolutely predictably, the results you're getting with this shoebox machine are sh*te, and always will be.
 
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