I want to use the k1803 as a pre in a bass amplifier. For this the input impedance has to be high. Can anyone tell me what the actual input impedance is?
Do you have the new version or the old version of the kit? (old version uses 741 IC)
I haven’t bought it yet, so I’m assuming the new version.
Input impedance of new model is around 50K.
Thank you,
That’s a bit low for a bass guitar and specially for a piezo equiped double bass. Is there an easy way to raise the impedance by substitution of some components?
You could multiply the value of every resistor in the kit with a constant factor.
Sorry, no values, please experiment.
Hi
i have just built the kit (new version LM358N)
i have conected a small electret microphone across the inputs and powered the circuit from 12v dc
all i get on the output is a constant value of about the input voltage
no variation as i was expecting with voice or tapping the mic ?
the gain pot has no efect on this either
i have checked all components etc and that all are in corect orientation ?
can anybody help me am i doing something wrong by just conecting the small electret mic across the two input pins
thanks
gremlin
An electret mic also needs a power supply.
We have sent you a mail which shows how to connect an electret mic.
would you be so kind as to resend the e-mail with the info as i have not recieved it
regards
gremlin
would you be kind enough to post the diagram on here or a lonk to download
as it does not look like it will come through to me e-mail
regards
mark
great thanks i will give that a go tommorow
is the capacitor just a ceramic disk or is it another type ?
regards
gremlin
Cap is a multilayer cap.
Ceramic cap will work too.