Cassette recorder microphone modifications

Thread Starter

BigOak14

Joined Apr 17, 2022
1
Hi there everybody
I have a new portable cassette recorder, but it has a terrible internal microphone, I was wondering if there was any way to unsolder the microphone and attach the aux cable of a lavlier microphone for better audio quality?
 

Audioguru again

Joined Oct 21, 2019
4,693
What is terrible about the internal mic? Distortion? No bass or boomy bass? No highs or noise (hisss)?
How do you know the problem is the from microphone and not in the recorder circuit?

Portable cassette recorders have not been made or used for at least 25 years. Of course Amazon and ebay still sell the old ones today. They used poor quality dynamic (coil and magnet) microphones.

Modern lavalier microphones are electret type that produce excellent sound but they must be powered.
 

panic mode

Joined Oct 10, 2011
2,135
there could be many issues and microphone may not even be the problem. could be that heads are misaligned or something else is not right. did you try feeding some signal to aux to verify that fixes the quality problems? if so, then by all means do something about the microphone.

you may try moving existing mic out of the recorder. that would make sense if the problem is due mechanics noise. maybe the unit was tampered with and the mic is not supported properly (need soft mount using rubber boot). if the goals is to replace it, should first try confirm the type. different mics have different impedance and as mentioned electret mics need to be powered. microphone itself may be using 3 terminals, the ones i saw recently are usually just two. either way most will be ok with a resistor such as 10-15k and 9V.

Replacement circuit may be something like this:
1650464262844.png
Of course if you are putting this into recorder, you do not need switch and battery, you can tap into internal power.
 

Audioguru again

Joined Oct 21, 2019
4,693
I was working for Philips when they invented the compact tape cassette. It replace the 8-track player in car radios in 1968 when I was in the car radios engineering department. I bought a portable AM-FM radio with cassette recorder/player but I never used the cheap microphone it came with.

The cassette recorder/player in this thread has an internal mic so maybe it has a restricted bandwidth for voice dictation.
 

Audioguru again

Joined Oct 21, 2019
4,693
A few days ago I looked in Google to see if anybody still sells cassette recorder/players. Today in the internet news I got an ad from a place that sells old ones for a very high price.
 
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