Maker Pro
Maker Pro

Audio signal conversion

dortbinbir

Apr 21, 2023
2
Joined
Apr 21, 2023
Messages
2
Hello,
I'm making a pre-amp that utilizes TDA7318 (yes its old) and an analog VU-meter (with driver board) along with an Arduino Mega as a controller and a Nextion TFT for display and input.

So far so good, however, the TDA7318 audio output is 4.5V whilst my Vu-meter (nakamichi branded) requires a line-level input. Therefore, a conversion is required between them. I'm just ignoring impedance difference (if any) since it's above my poor electronics knowledge.

Appreciate any help.

Thanks
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,794
Joined
Nov 17, 2011
Messages
13,794
Use a resistive voltage divider. Depending on the curent the VU meter requires, you may also use a trim potentiometer to fine-adjust the VU's display.
 

crutschow

May 7, 2021
863
Joined
May 7, 2021
Messages
863
You could also use just a trimpot with the resistive element connected between the TDA7318 output and ground, and the wiper connected to the VU meter input.
A 5k to 10kΩ trimpot should likely work.
 

danadak

Feb 19, 2021
823
Joined
Feb 19, 2021
Messages
823
Does the VU meter board require an offset range V span to accommodate it ?

If so this will help, attached.


Regards, Dana.
 

Attachments

  • sloa030a.pdf
    137.3 KB · Views: 2
  • Gain and Offset.pdf
    230 KB · Views: 1

AnalogKid

Jun 10, 2015
2,927
Joined
Jun 10, 2015
Messages
2,927
Can you post any information or links to the VU meter and its board?

ak
 

AnalogKid

Jun 10, 2015
2,927
Joined
Jun 10, 2015
Messages
2,927
A VU meter

If that was a response to my question, you misunderstood. I have some familiarity with what a VU meter is (and a copy of Howard Chinn's book).

My question was for the TS, to see exactly what he is working with. There are many things out there that are called a VU meter, but do not meet most of the requirements for one. His meter has a "driver board", and that raises a bunch of questions.

Also, the adafruit link is to a different product line.

ak

 
Last edited:
Top