Hi,
I want to change the stock microcel electret condenser microphones for these ones.
Do I need to change any resistors or capacitors, or even use a bigger battery to get the best signal to noise and performance, or should they be ok as a direct substitute?
The MK136 is my first diy project.
Thanks for any help! Spec differences below:
Velleman ECM
Pattern Omni-directional
Sensitivity: -61±3dB 0dB = 1V/1µbar, 1KHz
Impedance Low
S/N ratio 40dB or more
Maximum input sound level 120dB SPL
Standard voltage 4.5V
Current drain: 0.5mA Vcc = 4.5V, RL = 1K Ohm
BT-ECM
ECM
Pattern Omni-directional
Sensitivity -28 dB at 1 kHz (0 dB=1V/Pa)
Equivalent Noise Level 14 dB
Impedance 2.4K
S/N (SNR) Signal-to-noise Ratio > 80 dB at 1 kHz (1 Pa, A weighted)
Max input sound level 122 dB S.P.L.
Operating Voltage 5 VDC (3 to 10V)
Current 600uA max at Vcc=3VDC
CAUTION:
The ECM must be operated at or near its nominal operating voltage. Operation at too low a voltage will produce excessive self-noise.
I bought another one, assembled it with BT ECM mics and am running it on a 9v pp3 battery, just to see if any improvements in snr.
Would I be correct in assuming that there will now be 4.5v bias going to each microphone, instead of 2.25v?
I am trying to give the NE532 and the mics a little more power to see if any difference in hiss will be made, but noise seems identical to the original (3 AA) 4.5v supply.
Not that the unit is too noisy, just experimenting.
I will go to 18v, see if that makes any difference and then call it quits!
Just a tip for anyone building this minikit into a plastic box, and getting interference when connecting to other equipment,
buzzes hums etc…
Covering the inside of the casing with copper foil works a treat.
I just finish making of a bass viola da gamba, by my one self.
I am passionate about this instrument.
The sound is very, very good and powerfull.
So now, I want to make an electric bass viol to be able to make music without noise.
I thought, after reading spécifications on website, I can use electret microphone, préamplifier and headphones.
The MK136 Velleman seems to be a good start and inexpensive kit, to start this project.
Can you tell me what do you think about it?
(MK 136 suite).
Hello.
I forgot to mention the use of elecrets : I actually do not want to use them as surround microphone, but rather as a Neuman’s microphone.
I’ll put them under the bridge, directly through the soundboard.
I solder a small wire between the circuit board and microphones.
This assembly is simply expected to hear the sound and not stream high fidelity.