I recently purchased a Casio CDP-230R digital piano, which so far has been working quite nicely, apart from one feature. It comes with a 1/4" microphone jack, with which you can sample a sound and then play it back using the piano keys. I have yet to get it to pick up any sound from either of two microphones: one that I got for my pre-school daughter (a very cheap Disney-branded plastic microphone with a flaky cord) and a nicer one that I ordered just this week (a Shure PG58 dynamic microphone), despite following the piano user manual's instructions to the letter.

What I've noticed is that if I plug a powered sound source (such as my cell phone playing an MP3) into the piano's microphone jack, the sound comes through as you would expect, its volume can be adjusted using the microphone jack's volume knob, and it can be sampled as per the user manual's instructions. However, the manual makes no mention of needing an amplified sound source, the diagram on page 18 shows a (presumably) unpowered microphone being plugged directly into the microphone jack, and the one relevant Google result I've found is from a user who says he "Just plugged it in and worked."

Does anyone have experience with the microphone input on this or a similar piano? Does it need a pre-amp, or am I just picking the wrong kinds of microphones, or might the jack be faulty?

  • Don't mean to insult you or anything but the Shure PG58 has an on/off switch. Also there is a chance that the mic cable has a short in it. Plug the Shure mic into another amp with same cord and see if it works. Just eliminating all the obvious potential problems. I had a similar keyboard and just plugged in the mic and it worked fine. Commented Feb 7, 2015 at 7:19

2 Answers 2


Assuming the lead and plug on the new mic are both sound, another consideration is that the jack on the mic will be a mono 1/4 jack, whereas the input on Casio is stereo 1/4 jack. It may be that the mono jack is shorting the circuitry inside the keyboard. A solution, if this is the case, is to change the jack on the lead for a stereo one, and connect only tip and sleeve, leaving the ring part alone.That will only produce sound from left OR right. There is also a possibility to connect tip and ring, but this may mess up the internal circuitry on the Casio. Or contact Casio for a solution.

  • As best I can tell right now, it probably is a problem with mono vs stereo, but in the opposite direction. The microphone cable I bought has a stereo plug. Today we replaced my daughter's cheap microphone with one that works. That microphone has a mono plug, and when I plugged that into the piano, it immediately worked with the piano. When I plugged the Shure into my daughter's new microphone amp, I got no sound at all. I'll probably pick up a stereo-to-mono adapter from Radio Shack just to verify it's a plug problem and not a cord problem, but at least the question at hand is resolved. Commented Feb 18, 2015 at 23:46

these are the specifications for the CASIO CDP 230R:

Mic in: 6.3mm mono jack. Input Impedance: 3 kΩ, Input Sensitivity: 10 mV Recommended is a microphone cable with a 6.3 mm standard plug in mono. Do not use a stereo cable and a adapter.

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