Hi all.
Could you please give me some guide line for making a preamp with variable gain (60db or if possible 100db) with relatively accessible parts?
I was able to achieve a fixed 60db preamp with simple parts and dual 12v supply (with +-12v) and inspired with this project. sorry if it seems noob.
Now the problem is i now have a single 5v supply instead of dual ±12v.
Could you please give me some guide line for making a preamp with variable gain (60db or if possible 100db) with relatively accessible parts?
I was able to achieve a fixed 60db preamp with simple parts and dual 12v supply (with +-12v) and inspired with this project. sorry if it seems noob.
Now the problem is i now have a single 5v supply instead of dual ±12v.
Last edited:
unfortunately I do not have access to those websites.
I'm a new by in electronics, but based on my searches, there are two types of dc/dc converter. SMPS and ChargePump. SMPS cause noise while ChargePump do not. ChargePump have high ripple while SMPS do not. Does it really matters? is there significant different for my case?
Thanks
I'm a new by in electronics, but based on my searches, there are two types of dc/dc converter. SMPS and ChargePump. SMPS cause noise while ChargePump do not. ChargePump have high ripple while SMPS do not. Does it really matters? is there significant different for my case?
Thanks
Last edited:
Rise voltage above what you need, say +/-18 or 20-22V or so with a charge pump, and get very clean noiseless +/-12 or 15V out of those raw rails with a couple regulators, 781x/791x
Not sure you are aware of how much gain 100dB means.
60dB is already high enough to give you trouble.
Noise, hum, vibration, RF interference, feedback; you-name-it.
What are you trying to pick up with that contact microphone?
Not sure you are aware of how much gain 100dB means.
60dB is already high enough to give you trouble.
Noise, hum, vibration, RF interference, feedback; you-name-it.
What are you trying to pick up with that contact microphone?
Actually this is a variable preamp. I'm not sure even it be used with 100db gain (not often used with higher than 60db), just wanted to inform it is high gain and noises are not welcome.
Actually i want to use it as geo-phone preamp with RF shield and other caring, to magnify osculations as small as possible.
Thanks anyways for the tips
Actually i want to use it as geo-phone preamp with RF shield and other caring, to magnify osculations as small as possible.
Thanks anyways for the tips
Last edited: