22
votes
Accepted
Normal capacitor vs. audio capacitor
Let's forget about audio for now and try to find where the price difference lies in the specific products you mentioned, first.
Main reason: the ebay seller of the Vishay cap seems to mistake his ...
- 16k
10
votes
Normal capacitor vs. audio capacitor
I was curious, because I have the feeling that a component being "audio" is partly driven by belief, but in so many cases there are underlying reasons for that belief to be sensible. In the most ...
- 654
8
votes
Electrical specification for minimum bias current available from 3.5mm cellphone microphone input?
(Not enough reputation to comment on @Kevin Reid's answer so I have to do so in another answer.)
The Android docs are a useful source of info regarding this question. I interpret them differently ...
- 111
8
votes
Normal capacitor vs. audio capacitor
Question: what kind of difference is there between such a capacitor, for "audio applications"
First "audio application" doesn't mean anything. A capacitor can serve many different uses, for example ...
- 72k
6
votes
How are the PNP transistors biased in this microphone circuit?
The base resistors don't have to go to ground. They just have to go to a node that's at a sufficiently lower voltage than the base to turn it on. In this case, it's the collectors.
This circuit is ...
- 2,061
6
votes
Accepted
I need to generate a +200V polarization voltage (Stable, low noise, micro-amp output)
The laziest approach is to simply buy a DC-DC converter. More like $50 one-off than $4K. An isolated one will give you the most flexibility. I see 10mV p-p ripple as a standard spec. Eg. Bellnix BYH ...
- 384k
4
votes
Normal capacitor vs. audio capacitor
I think that the authoritative work on audio is Doug Self's "Small Signal Audio Design", and in it Doug looks in some detail at things like distortion in capacitors. His observations are not some ...
- 6,604
4
votes
Accepted
Best microphone picking up sound within a small room?
You need to pay attention to the following items:
High sensitivity - measured in dB, and always negative. You want a value closer to 0. That is to say that -38 is better than -44. Sensitivity is ...
- 69.1k
4
votes
Accepted
Filter of DC does not work?
You would need a resistor from the output to Ground to remove the offset. Without a resistor to ground, leakage in the capacitor will hold the output voltage near the voltage at the bottom of R1.
- 58.1k
4
votes
Accepted
How conductive is aluminized mylar?
I cut a 2 cm square out of a mylar 'space blanket', and placed my digital multimeter probes flat on either side to measure resistance from one side to the other. The reading (on the 200 Ω scale) was 1....
- 55.8k
3
votes
Accepted
Electrical specification for minimum bias current available from 3.5mm cellphone microphone input?
It's not a universally applicable standard, but Android publishes specifications for headset plug and jack.
These documents (as of June 14, 2017) specify that the jack's mic bias voltage shall be in ...
- 7,504
2
votes
Accepted
Any tips on designing an audio preamplifier for low frequencies?
1 - Quite probably
2 - This search says its quite possible also.
3 - While C1 and C2 block DC they will also be a RC filter, which will hinder low frequency reproduction.
You'd need higher values ...
- 7,864
2
votes
How to get output voltage of microphone?
You assume the microphone is linear.
This means that when the sound level input to the microphone changes by 1dB, the output voltage of the microphone changes by 1dB.
Some old (very old) pointer ...
- 162k
2
votes
Combining two phantom power microphone capsules
The AKG PT40 Pro manual, page 17, states
You can use the PT 40 PRO bodypack transmitter with both dynamic microphones and condenser microphones operating on a supply voltage of approx. 4 V. You may ...
- 171k
2
votes
Best microphone picking up sound within a small room?
When I wanted a microphone to record voice, the USB headset was so noisy that it was unusable. (with a microphone right in front of the mouth)
It required a BC547 transistor pre-amp, extra power ...
- 5,323
2
votes
Condenser and electret microphone use
No. While it probably is possible to cause the diaphragm to move with an applied signal, the resulting audio will be severely distorted and almost completely inaudible. You would have better luck ...
- 18.2k
2
votes
Why might a condenser microphone suddenly only record very close sounds?
Welcome to the board, Joel. Let's try to do some remote troubleshooting.
It's important to recognize that the problem could originate not just in the microphone, but in the computer's USB sound driver ...
- 5,181
2
votes
Accepted
Why won't my pre-amp circuit enable my condenser microphone to work with my boombox?
The "condenser microphone" is a simple electret condenser that is powered by the computer. All it needs is power. Most condenser capsules are specified to work for something like 2V to 10V ...
- 3,613
1
vote
Random Electrical noise LM386
Sounds like you built an oscillator instead of an amplifier.
Try removing V1 to reduce the gain and see if the circuit stabilizes.
Try making R1 a low value, more like 10Ohm, not 10k.
Or try ...
- 4,629
1
vote
Accepted
AC-Coupling blocking negative voltage values
The guy in the video misspoke. It's the transistor that's cutting off half of the waveform, because of how it's biased. The blocking capacitor simply eliminates the bias that's already on the ...
- 170k
1
vote
Accepted
LM386L does not amplify the microphone signal
Googling "condenser microphone circuit" shows lots of schematics that have three things yours is missing
As does the image in this Question on biasing a condenser mic
Where does the other side of ...
- 7,373
1
vote
Accepted
Uni-Directional Electret Microphones and an Arduino
The circuit you show leaves out an important detail for using electret microphones:
Electret microphones need a source of DC to operate. The circuit you show left that out.
The circuit in the ...
- 69.1k
1
vote
How to find these resistance values in microphone phantom power power supply?
10mA is the maximum current the mic is allowed to draw in normal operation (For sizing the resistors you should of course assume a shorted mic cable), and at full 10mA you still need to have some ...
- 17.4k
1
vote
Can I wire the ouput and Vcc of an electret condenser microphone amplifier and get the same signal out?
Two-wire operation is a compromise for low-powered signal sources. The output of an electret mic is matched well to that application regarding currents and signal levels and impedance and SNR ratio. ...
- 3,613
1
vote
Microphone sensor for picking up voice from across the room
As a kid, building high-gain bipolar ac-coupled amplifiers, the only signal source I had was a 2" transistor radio speaker. Scratch on the cone, for strong signals. Speak into the cone, for normal ...
- 33.8k
Only top scored, non community-wiki answers of a minimum length are eligible