[moved] Query about VU meters (led bargraph)

[Audioguru]

Connect both shielded inner wires together for the signal wire and use the stranded outer wires as the shield. The grounds of the input signal and of the amplifier do not need to be earthed, the ground is simply a common connection between an input device and an output device.

 

[Enzy]

I came back late, I did the ground connectionwhat I realize is that when I changed wires to the shielded cable it seems as if I lost volume, when nobs are in the center after the last test I was getting like 6v rms.... And previously I was getting like 23v. My friend had some music to play and needed an amp so I gave him to play 6 speakers and 2 horns I don't know the speaker specs but it played them well

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I want to build another one but I would rather not to purchase any more of those Chinese amplifiers, just like how I got help to design the preamp I would like to do a amplifier