Close
0%
0%

Piezo preamp rebuild

My Stagg double bass has a noisy preamp that precludes recording it. I should replace it. One day.

yann-guidon-ygdesYann Guidon / YGDES
Following
Liked Like project

Just one more thing

To make the experience fit your profile, pick a username and tell us what interests you.

Pick an awesome username
hackaday.io/
Your profile's URL: hackaday.io/username. Max 25 alphanumeric characters.
Pick a few interests
Projects that share your interests
People that share your interests

We found and based on your interests.

Choose more interests.

OK, I'm done! Skip
Similar projects worth following
729 views
4 comments
16 followers
View Gallery
This is a "placeholder" project to remind me that I should, among other things, design a proper, ultra-low-noise preamp to replace the lousy circuit installed in this bass. Since my 20S, I'm used to replace the electronics of my 4-stringers but this one is piezo and I should investigate more instead of putting a '741 in voltage follower configuration...

Logs:
1. A discrete op-amp ?

  • A discrete op-amp ?

    Yann Guidon / YGDES • 05/02/2016 at 00:34 • 0 comments

    Coincidences are great.

    I need to make a preamp (voltage follower, mostly) for this bass. Impedance must be low but noise must be minimal.

    OTOH in another project, I am considering building a discrete amplifier.

    I could use an integrated circuit but I'm not sure that would answer all the questions that might appear. But since low-noise, low-power signal amplification is a goal shared with another project, it is possible to share insight and designs.

View project log

Enjoy this project?

Share

Discussions

AVR wrote 05/21/2016 at 19:20 • point

Following cause I wanna do custom guitar piezo electronics, eh and MIDI digitizing :)

  Are you sure? yes | no

Vito wrote 05/02/2016 at 09:01 • point

You don't need to make an entire op-amp for that: I suggest you a J-Fet preamp and careful shielding:

http://www.rason.org/Projects/jfetamp/jfetamp.htm

  Are you sure? yes | no

Yann Guidon / YGDES wrote 05/02/2016 at 14:58 • point

Hello Vito,

Indeed I'm looking at discrete JFET amplification for the #Active scope probe with no dedicated power supply. While looking at differential amplifiers on google, I found a lot of audio circuits as well, including this one

I don't remember where I found it but with some enhancements (offset trimming, current sources instead of certain resistors) it makes a semi-decent op-amp that I can set to unity gain. That got my headgears spinning...

I won't try to reinvent something revolutionary, just remove the noise that keeps me from using my instruments for recording. I know that audio amplification is one of the golden applications of electronics and everything has been tried already :-D

If you have other F-FET suggestions, thank you for sending more links, I'll study them !

  Are you sure? yes | no

Does this project spark your interest?

Become a member to follow this project and never miss any updates

Going up?

About Us Contact Hackaday.io Give Feedback Terms of Use Privacy Policy Hackaday API

© 2025 Hackaday

Yes, delete it Cancel

Report project as inappropriate

You are about to report the project "Piezo preamp rebuild", please tell us the reason.

Send message

Your application has been submitted.

Remove Member

Are you sure you want to remove yourself as a member for this project?

Project owner will be notified upon removal.