t30 microphone -turn-off

[Dave_s]

With an audio cable is plugged into the line-in jack, my voice is heard and recorded in addition to the audio coming in from the line-in sounds. The 30's built-in mic is still listening.

I cannot find any options in the T30 to turn-off the built-in mic when using the line jack.

Any help is really appreciated. Thanks, Dave_s

[jdhurst]

I forget my T30 but I think it was SoundMax. On my T41 with SoundMax, there is an option in the SoundMax settings (Control Panel) to choose standard microphone or headset. Does that help?
... JDH

[aditya1956]

The MIC input probabely is not switched off. You can do the following to switch it off.

Dbl click the spk icon in the sys tray. It will show you the inputs available at the moment.

If you can see the mic fader......then check the mute_box below the mic fader. You should also pull the slider down to zero as there is always the fear of leakages which happens in many of the cards, even good ones.

If you can not see the mic fader.......then from the top left corner of the page choose option>properties>playback. This will show you all the inputs. Select microphone, and click OK. Now it will be visible. Switch it off as mentioned earlier.

You should also open Options>Properties>Recording.
Choose mic, and disable it by un_checking the box.
You should also pull the mic fader down to zero.

Actually in general, it is safer to choose only the master, cd, line, mic, wave, pc-speaker and disable the rest in both the recording and playback choices. Note that only one input is enabled in the recording page unlike the playback page where many/all can be enabled.

Hope this helps.

[Dave_s]

With my T30, I am trying to record sounds using an external mic.
Apparently, not every type external mic works with my T30 mic input. I have external elecret mic's that do not work with my T30 but do work well into audio amplifiers. Do mics need to be crystal or dynamic type mics to work with my T30? Has anyone been able to use an elecret mic with their T30? I suspect the T30 is not providing the needed bias voltage that elecret mics need.
Thanks for any help. Dave_s




What type external mic

[aditya1956]

Pls confirm what input you are using to do your recording. Your OP said it to be the line_input and now you are mentioning about the mic_input. Both of these need different approaches to do a successful job.

As far as the type of mic is concerned, you will be able to use only an electret type here as the original IBM mic is also an electret type, and that means there is a bias voltage already there. Dynamics will work but will sound low or distorted, and even may get damaged if connected for very long periods. Crystal mics are no more used for normal audio recordings.

I think any standard computer mic should work here unless the bias wiring inside the T30 is proprietary, which I don't think the case to be here. My T20 works well with the mic of a standard headphone/mic combo by using only the mic jack of the combo.

What microphone are you using ? I mean any specific make etc.

Can you connect a stereo type mini jack (only jack) into the mic_input of the T30 and measure the voltages between the earth tag (the longest) and the other two ? This will help in giving the correct solution. You can also try with few other generic mics meant for computers.

Thanks

[aditya1956]

I just got another idea which will help you now to get along with your work in the mean time before you locate/solve the suitable mic issue.

Connect a "2 RCA to 1 mini stereo cord" between your amp's tape_out and the T30's line_in. Disable the speakers of the amp, and connect any standard headphone to your T30's HPhone socket.

If you have a mic gain control on your amp, then set it to the 1 o'clock position,
and your T30's "Options>Properties>Recording>Line-in slider to the last but one position.
Adjust the line-in in your Playback also to the same position.
Set the Master volume control of T30 to zero and adjust for a suitable volume level while you are speaking into the mic.

Once set you can start recording.

Cheers

[Dave_s]

>Pls confirm what input you are using to do your recording. Your OP >said it to be the line_input and now you are mentioning about the >mic_input. Both of these need different approaches to do a >successful job.

You are correct. I am recording using an external common PC mike [elecret], no brand name in one application. Using the mic input.

The other application, I did use the line-in input and needed to turn-off the T30 built-in mike.

>As far as the type of mic is concerned, you will be able to use only >an electret type here as the original IBM mic is also an electret >type, and that means there is a bias voltage already there.

I will measure the bias voltage.

>I think any standard computer mic should work here unless the >bias wiring inside the T30 is proprietary, which I don't think the >case to be here. My T20 works well with the mic of a standard >headphone/mic combo by using only the mic jack of the combo.

Several of my hand-wired elecret capsule mikes work OK with T30. One commercial prewired elecret won't work and other prewired mics do work.

Your info did help.


>What microphone are you using ? I mean any specific make etc.

No brand name mic. I bought omni-mic elecret cartridges and wired my own mics. I was careful to wire bias voltage correctly to jack.

>Can you connect a stereo type mini jack (only jack) into the >mic_input of the T30 and measure the voltages between the earth >tag (the longest) and the other two ? This will help in giving the >correct solution. You can also try with few other generic mics >meant for computers.

Yes I can measure bias.

Thanks

[aditya1956]

Glad to know that it helped.

That particular pre-wired mic might have followed a non-standard wiring inside and as a result is not working.

Cheers